كتاب خواص المواد واختباراتها الجزء الاول

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‫אصאאدوא א‪K‬د‪L‬دم‪ J‬م‪K‬د‪ JL‬د‪ L‬‬

‫ ‬ ‫ ‬ ‫‪ 1 –1‬‬

‫ﺍﻟﻌﻠﻮﻡ ﺍﳍﻨﺪﺳﻴﺔ ﻣﺎ ﻫﻰ ﺇﻻ ﻋﻠﻢ ﻭﻓﻦ ﻳﻌﻤﻞ ﻋﻠﻰ ﺍﺳﺘﻐﻼﻝ ﺍﳌﻮﺍﺩ ﻭﺍﳌﻮﺍﺭﺩ ﻭﻗـﻮﻯ ﺍﻟﻄﺒﻴﻌـﺔ ﻟﻠﺘﻄـﻮﺭ‬ ‫ﻭﺍﻟﺘﻘﺪﻡ ﺍﻟﺼﻨﺎﻋﻰ ﻭﺍﻟﺘﻜﻨﻮﻟﻮﺟﻰ ﻭﺍﻟﻌﻤﺮﺍﱏ‪ ،‬ﻭﻳﻌﺘﻤﺪ ﻫﺬﺍ ﺍﻟﺘﻘﺪﻡ ﺃﺳﺎﺳﹰﺎ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﺨﺘﻠﻔـﺔ‬ ‫ﻭﻋﻠﻰ ﻣﺪﻯ ﺍﻟﺘﻘﺪﻡ ﰱ ﺗﻄﻮﻳﺮﻫﺎ ﻭﲢﺴﲔ ﺧﻮﺍﺻﻬﺎ ﻟﻜﻰ ﺗﻮﺍﻛﺐ ﺍ‪‬ﺎﻻﺕ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ‪ .‬ﺇﻥ ﺍﳌـﻮﺍﺩ‬ ‫ﺑﺼﻔﺔ ﻋﺎﻣﺔ ﻫﻰ ﻋﺼﺐ ﺍﻟﻌﻠﻮﻡ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﺘﻨﻮﻋﺔ ﰱ ﻣﺎﻫﻴﺘﻬﺎ ﻭﻣﻘﻮﻣﺎ‪‬ﺎ‪ ،‬ﻭﺃﺻـﺒﺤﺖ ﻣﻮﺿـﻊ ﺍﻫﺘﻤـﺎﻡ‬ ‫ﻟﻠﻤﺘﺨﺼﺼﲔ ﻭﺍﻟﺒﺎﺣﺜﲔ ﻷﳘﻴﺘﻬﺎ ﰱ ﺧﺪﻣﺔ ﺍﻟﺒﺸﺮﻳﺔ ﰱ ﻛﻞ ﺍ‪‬ﺎﻻﺕ ﺍﳌﺨﺘﻠﻔﺔ ﺳﻮﺍﺀ ﻛﺎﻧﺖ ﻫﻨﺪﺳـﻴﺔ ﺃﻭ‬ ‫ﻃﺒﻴﺔ ﺃﻭ ﺯﺭﺍﻋﻴﺔ ﺃﻭ ﻏﲑ ﺫﻟﻚ‪ .‬ﻭﻋﻠﻴﻪ ﻛﺎﻥ ﻋﻠﻰ ﺍﳌﻬﻨﺪﺳﲔ ﺍﳌﺘﺨﺼﺼﲔ ﺍﻟﻜﺸﻒ ﻋﻦ ﺃﺳـﺮﺍﺭ ﺍﳌـﻮﺍﺩ‬ ‫ﻭﺍﻹﺣﺎﻃﺔ ﲟﻜﻮﻧﺎ‪‬ﺎ ﻭﺍﻟﺘﻌﺮﻑ ﻋﻠﻰ ﻛﺎﻓﺔ ﺧﻮﺍﺻﻬﺎ‪.‬‬ ‫ﻭﻣﻦ ﻫﻨﺎ ﳚﺊ ﺩﻭﺭ ﻋﻠﻢ "ﺧﻮﺍﺹ ﻭﻣﻘﺎﻭﻣﺔ ﺍﳌﻮﺍﺩ ﻭﺍﺧﺘﺒﺎﺭﺍ‪‬ﺎ" ﻟﻴﻜﻮﻥ ﺃﺣﺪ ﺍﻷﺳﺲ ﺍﻟﺮﺋﻴﺴﻴﺔ ﻷﻯ ‪‬ﻀﺔ‬ ‫ﺗﻜﻨﻮﻟﻮﺟﻴﺔ ﺣﺪﻳﺜﺔ‪ ،‬ﻭﳑﺎ ﻻ ﺷﻚ ﻓﻴﻪ ﻓﺈﻥ ﺩﻭﺭ ﻋﻠﻢ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻮﺍﺩ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﻟﻨﻈﺮﻳﺎﺕ ﻭﺍﻟﻌﻠﻢ ﺍﳋـﺎﻟﺺ‬ ‫ﰱ ﺩﺭﺍﺳﺔ ﺍﻟﻌﻠﻮﻡ ﺍﳍﻨﺪﺳﻴﺔ ﻟﻴﺲ ﺑﺎﻟﺸﻜﻞ ﺍﳌﻼﺋﻢ‪ ،‬ﺣﻴﺚ ﺃﻧﻪ ﳚﺐ ﺗﻨﻤﻴﺔ ﺩﻭﺭ ﻫـﺬﺍ ﺍﻟﻌﻠـﻢ ﺑﺎﻻﻫﺘﻤـﺎﻡ‬ ‫ﺑﺎﻟﻨﻮﺍﺣﻰ ﺍﻟﻌﻠﻤﻴﺔ ﺍﻟﻨﻈﺮﻳﺔ ﻣﻊ ﺍﻟﻨﻮﺍﺣﻰ ﺍﻟﻌﻠﻤﻴﺔ ﺍﻟﺘﻄﺒﻴﻘﻴﺔ ﺍﳍﻨﺪﺳﻴﺔ‪ ،‬ﻟﻜﻰ ﻳﺘﻤﻜﻦ ﻛﻼ ﻣـﻦ ﺍﻟﺪﺍﺭﺳـﲔ‬ ‫ﻭﺍﳌﻬﻨﺪﺳﲔ ﺃﻥ ﳚﻤﻌﻮﺍ ﺑﲔ ﺍﳌﺒﺎﺩﺉ ﺍﻟﻌﻠﻤﻴﺔ ﻭﺍﳋﱪﺓ ﺍﻟﻌﻤﻠﻴﺔ ﺍﻟﻼﺯﻣﲔ ﻟﻌﻤﻞ ﻭﺻﻨﺎﻋﺔ ﺍﳌﻮﺍﺩ ﻭﺍﻻﺳـﺘﻔﺎﺩﺓ‬ ‫ﻣﻨﻬﺎ‪ .‬ﻭﻟﻜﻰ ﻧﺘﻤﻜﻦ ﻣﻦ ﺍﻟﻮﺻﻮﻝ ﺇﱃ ﺫﻟﻚ ﳚﺐ ﺃﻥ ﻳﻜﻮﻥ ﺍﻟﺒﺎﺣﺚ ﻭﺍﳌﻬﻨﺪﺱ ﻋﻠﻰ ﺩﺭﺍﻳﺔ ﻛﺒﲑﺓ ﺑﺈﻧﺸﺎﺀ‬ ‫ﻣﻮﺍﺩ ﺟﺪﻳﺪﺓ ﺃﻭ ﲢﺴﲔ ﻣﻮﺍﺩ ﻣﻮﺟﻮﺩﺓ ﻻﺳﺘﺨﺪﺍﻣﻬﺎ ﰱ ﳎﺎﻻﺕ ﻣﺘﻨﻮﻋﺔ‪ ،‬ﺑﺄﻥ ﳜﺘﺎﺭ ﻣﻮﺍﺻـﻔﺎﺕ ﺍﳌـﻮﺍﺩ‬ ‫ﺍﻟﻼﺯﻣﺔ ﻟﻠﺘﻄﺒﻴﻘﺎﺕ ﺍﻟﱴ ﺗﻄﻠﺐ ﻣﻨﻪ‪ ،‬ﺑﺄﻥ ﻳﻬﺘﻢ ﺑﻀﺒﻂ ﺟﻮﺩﺓ ﻛﻞ ﺍﳌﻮﺍﺩ ﺍﳌﺴﺘﺨﺪﻣﺔ ﻭﻃﺮﻕ ﺍﻟﺼﻨﺎﻋﺔ‪ ،‬ﺑﺄﻥ‬ ‫ﻳﻜﻮﻥ ﻋﻠﻢ ﺗﺎﻡ ﺑﺎﳋﻮﺍﺹ ﺍﳌﺨﺘﻠﻔﺔ ﻟﻠﻤﻮﺍﺩ ﺍﳌﺘﻨﻮﻋﺔ ﻭﻛﺬﻟﻚ ﺍﻟﻌﻼﻗﺎﺕ ﺑﻴﻨﻬﻤﺎ ﻭﻇﺮﻭﻑ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ‪ ،‬ﺑﺄﻥ‬ ‫ﻳﻘﺮﺭ ﻃﺮﻕ ﺍﻻﺧﺘﺒﺎﺭ ﺍﳌﻄﻠﻮﺑﺔ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﺃﻭ ﻋﻠﻰ ﻋﻤﻠﻴﺎﺕ ﺍﻹﻧﺘﺎﺝ ﻷﻯ ﻋﻨﺎﺻﺮ ﺇﻧﺸﺎﺋﻴﺔ ﺗﺴﺘﺨﺪﻡ ﺗﻠـﻚ‬ ‫ﺍﳌﻮﺍﺩ‪.‬‬ ‫ﻣﻦ ﻛﻞ ﻣﺎ ﺗﻘﺪﻡ ﳚﺐ ﺃﻥ ﻧﻌﺮﻑ ﺍﻟﺪﻭﺭ ﺍﻷﺳﺎﺳﻰ ﺍﻟﺬﻯ ﻳﻠﻌﺒﻪ ﻋﻠﻢ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻮﺍﺩ ﻭﺍﺧﺘﺒﺎﺭﺍ‪‬ﺎ ﰱ ﺗﻘـﺪﻡ‬ ‫ﺍﻟﻌﻠﻮﻡ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ‪ ،‬ﻭﻛﺬﻟﻚ ﻇﻬﻮﺭ ﺃﳘﻴﺔ ﻫﺬﺍ ﺍﻟﻌﻠﻢ ﰱ ﺍ‪‬ﺎﻻﺕ ﺍﻟﺼﻨﺎﻋﻴﺔ ﻭﺍﻹﻧـﺸﺎﺋﻴﺔ ﺣﻴـﺚ‬ ‫ﳜﺘﺺ ﻋﻠﻢ ﺧﻮﺍﺹ ﻭﻣﻘﺎﻭﻣﺔ ﺍﳌﻮﺍﺩ ﻭﺍﺧﺘﺒﺎﺭﺍ‪‬ﺎ ﺑﺪﺭﺍﺳﺔ ﺳﻠﻮﻙ ﻭﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﻭﺍﺧﺘﺒﺎﺭﺍ‪‬ﺎ ﲢﺖ ﺗـﺄﺛﲑ‬ ‫ﺍﻷﲪﺎﻝ ﺍﳌﺨﺘﻠﻔﺔ‪.‬‬ ‫‪١‬‬


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2-1‬‬

‫ﺇﻥ ﺍﻟﺘﻄﻮﺭ ﻭﺍﻟﺘﻘﺪﻡ ﺍﳍﺎﺋﻞ ﰱ ﺍﻟﻌﺎﱂ ﺃﲨﻊ ﻫﻮ ﺍﻟﺴﺒﺐ ﺍﻷﺳﺎﺱ ﻹﻇﻬﺎﺭ ﺩﻭﺭ ﻋﻠﻢ ﺧﻮﺍﺹ ﻭﻣﻘﺎﻭﻣﺔ ﺍﳌﻮﺍﺩ‬ ‫ﺍﻟﺬﻯ ﻳﺴﺎﻫﻢ ﺑﺸﻜﻞ ﻭﺍﺿﺢ ﰱ ﲢﻘﻴﻖ ﻫﺬﺍ ﺍﻟﺘﻘﺪﻡ‪ ،‬ﻷﻥ ﻫﺬﺍ ﺍﻟﻌﻠﻢ ﳜـﺘﺺ ﻭﻳﺒﺤـﺚ ﰱ ﺍﻟﺪﺭﺍﺳـﺎﺕ‬ ‫ﺍﻟﻌﻠﻤﻴﺔ ﻭﺍﻟﺘﻄﺒﻴﻘﻴﺔ ﻟﻠﻤﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﺍﻟﱴ ﺗﺴﺘﺨﺪﻡ ﰱ ﻛﺎﻓﺔ ﺍ‪‬ﺎﻻﺕ ﺍﳍﻨﺪﺳﻴﺔ ﺇﻧﺸﺎﺋﻴﺔ ﺃﻭ ﻣﻴﻜﺎﻧﻴﻜﻴـﺔ ﺃﻭ‬ ‫ﻛﻬﺮﺑﻴﺔ ﺃﻭ ﺻﻨﺎﻋﻴﺔ ﺃﻭ ﻏﲑ ﺫﻟﻚ ﰱ ﲨﻴﻊ ﳎﺎﻻﺕ ﺍﳊﻴﺎﺓ‪ .‬ﺇﻥ ﺩﻭﺭ ﻫﺬﺍ ﺍﻟﻌﻠﻢ ﺃﻳﻀﹰﺎ ﻳﺘـﻀﺢ ﰱ ﺗﻌـﻴﲔ‬ ‫ﻣﻌﻈﻢ ﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﺳﻮﺍﺀ ﻛﺎﻧﺖ ﻣﻮﺍﺩ ﻃﺒﻴﻌﻴﺔ ﺃﻭ ﻣﻮﺍﺩ ﻣﺼﻨﻌﺔ ﻣﻦ ﺧﻮﺍﺹ ﻃﺒﻴﻌﻴـﺔ ﺃﻭ ﻣﻴﻜﺎﻧﻴﻜﻴـﺔ ﺃﻭ‬ ‫ﻛﻴﻤﻴﺎﺋﻴﺔ ﺃﻭ ﺣﺮﺍﺭﻳﺔ ﺃﻭ ﻛﻬﺮﺑﻴﺔ ﺃﻭ ﺃﻯ ﺧﻮﺍﺹ ﺃﺧﺮﻯ ﻣﻄﻠﻮﺑﺔ‪ ،‬ﻭﻛﺬﻟﻚ ﲢﺪﻳﺪ ﻗﺪﺭﺓ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﲢﻤـﻞ‬ ‫ﺍﻷﲪﺎﻝ ﺍﳌﺨﺘﻠﻔﺔ ﻟﺪﺭﺍﺳﺔ ﺳﻠﻜﻮﻫﺎ ﻭﻛﻴﻔﻴﺔ ﺗﻄﻮﻳﺮﻫﺎ ﻟﻠﻮﺻﻮﻝ ‪‬ﺎ ﺇﱃ ﺧﻮﺍﺹ ﳑﻴﺰﺓ ﺟﺪﻳﺪﺓ‪ .‬ﻭﻣﻦ ﻫﻨـﺎ‬ ‫ﻳﺘﻀﺢ ﺃﻥ ﻫﺬﺍ ﺍﻟﻌﻠﻢ ﳜﺘﺺ ﺑﺎﻟﻌﺪﻳﺪ ﻣﻦ ﺍﻟﺪﺭﺍﺳﺎﺕ ﺍﻟﻌﻠﻤﻴﺔ ﻭﺍﻟﺘﻄﺒﻴﻘﻴﺔ ﻟﻠﻤﺎﺩﺓ ﰱ ﻛﺜﲑ ﻣـﻦ ﺍ‪‬ـﺎﻻﺕ‬ ‫ﻭﻳﺘﺮﻛﺰ ﺩﻭﺭ ﻫﺬﻩ ﺍﻟﺪﺭﺍﺳﺎﺕ ﰱ ﺍﻵﺗﻰ‪:‬‬ ‫‪.١‬‬ ‫‪.٢‬‬ ‫‪.٣‬‬ ‫‪.٤‬‬ ‫‪.٥‬‬ ‫‪.٦‬‬ ‫‪.٧‬‬ ‫‪.٨‬‬

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‫ﲝﺚ ﺩﺭﺍﺳﺔ ﺍﳋﻮﺍﺹ ﺍﳌﺨﺘﻠﻔﺔ ﻟﻠﻤﻮﺍﺩ ﺳﻮﺍﺀ ﻛﺎﻧﺖ ﺧﻮﺍﺹ ﻃﺒﻴﻌﻴﺔ ﺃﻭ ﻣﻴﻜﺎﻧﻴﻜﻴﺔ ﺃﻭ ﻛﻴﻤﻴﺎﺋﻴﺔ‪.‬‬ ‫ﲢﻠﻴﻞ ﺍﻻﺟﻬﺎﺩﺍﺕ ﻭﺍﻻﻧﻔﻌﺎﻻﺕ ﻟﻠﻌﻨﺎﺻﺮ ﺍﻹﻧﺸﺎﺋﻴﺔ ﻭﺍﳌﺎﻛﻴﻨﺎﺕ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﳌﺨﺘﻠﻔﺔ ﲢـﺖ ﺗـﺄﺛﲑ‬ ‫ﺍﻷﲪﺎﻝ ﺍﻻﺳﺘﺎﺗﻴﻜﻴﺔ ﺃﻭ ﺍﻟﺪﻳﻨﺎﻣﻴﻜﻴﺔ ﺃﻭ ﺍﳌﺘﻜﺮﺭﺓ‪.‬‬ ‫ﲢﺪﻳﺪ ﺍﳋﻮﺍﺹ ﺍﳌﻤﻴﺰﺓ ﻟﻠﻤﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻭﻛﺬﻟﻚ ﺍﻟﻈﺮﻭﻑ ﺍﻟﻮﺍﺟﺐ ﻣﺮﺍﻋﺎ‪‬ﺎ ﻋﻨﺪ ﺍﺳـﺘﺨﺪﺍﻣﻬﺎ ﰱ‬ ‫ﺃﻯ ﳎﺎﻝ ﻫﻨﺪﺳﻲ ﻟﻠﻮﺻﻮﻝ ﺑﻪ ﺇﱃ ﺃﻋﻠﻰ ﻛﻔﺎﺀﺓ ﻓﻨﻴﺔ‪.‬‬ ‫ﺩﺭﺍﺳﺔ ﻭﲢﺪﻳﺪ ﺃﻧﻮﺍﻉ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﻼﺯﻣﺔ ﻟﺘﻌﻴﲔ ﺍﳋﻮﺍﺹ ﺍﳌﻤﻴﺰﺓ ﻟﻠﻤﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻟﻠﺘﺤﻘﻴﻖ ﻣـﻦ‬ ‫ﻣﻄﺎﺑﻘﺘﻬﺎ ﻟﻠﻤﻮﺍﺻﻔﺎﺕ ﻭﺍﻻﺷﺘﺮﺍﻃﺎﺕ ﺍﻟﻔﻨﻴﺔ ﺍﳌﻄﻠﻮﺑﺔ ﻟﺼﻼﺣﻴﺔ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﰱ ﺍﻷﻋﻤﺎﻝ ﺍﳌﺨﺘﻠﻔﺔ‪.‬‬ ‫ﺗﻌﻴﲔ ﺍﳋﻮﺍﺹ ﺍﳍﺎﻣﺔ ﺍﳌﻄﻠﻮﺑﺔ ﻟﻠﻤﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻟﺪﺭﺍﺳﺔ ﻣﺪﻯ ﲢﻤﻠﻬﺎ ﻣﻊ ﺍﻟﺰﻣﻦ‪.‬‬ ‫ﲡﻬﻴﺰ ﻭﺗﺼﻤﻴﻢ ﺍﳌﺎﻛﻴﻨﺎﺕ ﻭﺍﻷﺟﻬﺰﺓ ﺍﳌﺴﺘﻌﻤﻠﺔ ﰱ ﺍﺧﺘﺒﺎﺭﺍﺕ ﺗﻌﻴﲔ ﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﺍﳌﺨﺘﻠﻔﺔ ﻭﺩﺭﺍﺳﺔ‬ ‫ﺳﻠﻮﻛﻬﺎ ﲢﺖ ﺗﺄﺛﲑ ﺍﻷﻧﻮﺍﻉ ﺍﳌﺨﺘﻠﻔﺔ ﻣﻦ ﺍﻷﲪﺎﻝ ﰱ ﺍﳌﻌﻤﻞ ﺃﻭ ﰱ ﻣﻮﻗﻊ ﺍﻟﻌﻤﻞ‪.‬‬ ‫ﻋﻤﻞ ﺍﻟﺪﺭﺍﺳﺎﺕ ﺍﻻﻗﺘﺼﺎﺩﻳﺔ ﻭﺍﻟﻔﻨﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ ﻟﻮﺿﻊ ﺃﻓﻀﻞ ﺍﻟﻄﺮﻕ ﻻﺧﺘﺒـﺎﺭ ﺍﳌـﻮﺍﺩ ﺍﳍﻨﺪﺳـﻴﺔ‬ ‫ﻭﺍﻷﺳﻠﻮﺏ ﺍﻷﻣﺜﻞ ﻻﺳﺘﺨﺪﺍﻣﻬﺎ ﻣﻔﺮﺩﺓ ﺃﻭ ﻣﺮﻛﺒﺔ ﻣﻊ ﻣﻮﺍﺩ ﺃﺧﺮﻯ ﰱ ﺍﻷﻋﻤﺎﻝ ﺍﻹﻧﺸﺎﺋﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ‪.‬‬ ‫ﲝﺚ ﺩﺭﺍﺳﺔ ﲢﺴﲔ ﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻭﺫﻟﻚ ﻣﻦ ﺍﻷﲝﺎﺙ ﺍﻟﺴﺎﺑﻘﺔ ﺃﻭ ﺃﲝﺎﺙ ﺟﺪﻳﺪﺓ ﺟﺎﺭﻳـﺔ‬ ‫ﻭﺫﻟﻚ ﻟﻜﻰ ﺗﻼﺋﻢ ﺍﺳﺘﺨﺪﺍﻣﺎﺕ ﺃﻛﺜﺮ ﻓﺎﻋﻠﻴﺔ ﰱ ﳎﺎﻻﺕ ﺗﻄﻮﻳﺮ ﺍﻟﻌﻠـﻮﻡ ﺍﳍﻨﺪﺳـﻴﺔ ﺍﳌﺘﻘﺪﻣـﺔ ﺃﻭ‬ ‫ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﻣﻮﺍﺩ ﺟﺪﻳﺪﺓ ﺫﺍﺕ ﺧﻮﺍﺹ ﳑﻴﺰﺓ ﺗﺼﻠﺢ ﰱ ﳎﺎﻻﺕ ﺁﺧﺮﻯ ﻣﺘﻌﺪﺩﺓ ﻭﻣﺒﺘﻜﺮﺓ‪.‬‬ ‫ﲢﺪﻳﺪ ﻭﻭﺿﻊ ﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﻭﺍﺧﺘﺒﺎﺭﺍ‪‬ﺎ ﰱ ﺇﻃﺎﺭ ﻋﻠﻤﻰ ﳏﺪﺩ ﻭﺫﻟﻚ ﻟﻀﺒﻂ ﺟﻮﺩﺓ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ‬ ‫ﻭﺍﻷﻋﻤﺎﻝ ﺍﳌﺴﺘﺨﺪﻡ ‪‬ﺎ ﺗﻠﻚ ﺍﳌﻮﺍﺩ ﻭﻫﺬﺍ ﺑﻌﻤﻞ ﻣﻮﺍﺻﻔﺎﺕ ﻗﻴﺎﺳﻴﺔ ﻭﻗﻮﺍﻧﲔ ﺧﺎﺻﺔ ﲝﻤﺎﻳﺔ ﺍﳌـﻮﺍﺩ‬ ‫ﻭﺍﻷﻋﻤﺎﻝ ﺍﻹﻧﺸﺎﺋﻴﺔ‪.‬‬ ‫‪٢‬‬


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‫• ﺩﺭﺍﺳﺔ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﳍﺎ ﺩﻭﺭ ﻓﻌﺎﻝ ﻭﺃﳘﻴﺔ ﺧﺎﺻﺔ ﰱ ﺃﻯ ﺗﻘﺪﻡ ﺗﻜﻨﻮﻟﻮﺟﻰ ﰱ ﲨﻴـﻊ ﺍ‪‬ـﺎﻻﺕ‪،‬‬ ‫ﻭﻟﺬﻟﻚ ﻓﺈﻥ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻫﻰ ﺍﻟﱴ ﺗﻜﻮﻥ ﺍﻟﻜﻴﺎﻥ ﺍﻟﺮﺋﻴﺴﻲ ﻟﻸﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﺨﺘﻠﻔـﺔ‪ .‬ﻋﻠـﻰ‬ ‫ﺫﻟﻚ ﳚﺐ ﺍﳌﻌﺮﻓﺔ ﺍﻟﺪﻗﻴﻘﺔ ﻻﻧﻮﺍﻉ ﺍﳌﻮﺍﺩ ﺍﳌﺨﺘﻠﻔﺔ ﻭﲝﺚ ﺩﺭﺍﺳﺔ ﺧﻮﺍﺻﻬﺎ ﻭﺇﻣﻜﺎﻧﻴﺔ ﺍﺧﺘﺒﺎﺭ ﺃﻓـﻀﻞ‬ ‫ﻫﺬﻩ ﺍﳌﻮﺍﺩ ﻭﺍﻧﺴﺒﻬﺎ ﻟﺘﺘﻤﺎﺷﻰ ﻣﻊ ﻇﺮﻭﻑ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﰱ ﲨﻴﻊ ﺍﻷﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﻄﻠﻮﺑﺔ‪.‬‬ ‫• ﻭﻣﻦ ﻫﻨﺎ ﻧﺮﻯ ﺃﻥ ﺍﳌﻬﻨﺪﺳﲔ ﻭﺍﻟﺒﺎﺣﺜﲔ ﻣﻊ ﺍﺧﺘﻼﻑ ﲣﺼﺼﺎ‪‬ﻢ ﻻﺑﺪ ﳍﻢ ﻣﻦ ﺍﻟﺘﻌﺎﻣﻞ ﻣـﻊ ﺍﳌـﻮﺍﺩ‬ ‫ﺍﳍﻨﺪﺳﻴﺔ ﺑﻘﺪﺭﺓ ﻭﻛﻔﺎﺀﺓ ﻋﺎﻟﻴﺔ ﰱ ﲨﻴﻊ ﺧﻄﻮﺍﺕ ﺃﻯ ﻋﻤﻞ ﻫﻨﺪﺳﻰ ﻣﻄﻠﻮﺏ ﺗﻨﻔﻴﺬﻩ ﻟﻠﻮﺻﻮﻝ ﺑـﻪ‬ ‫ﻷﻋﻠﻰ ﺍﳌﺴﺘﻮﻳﺎﺕ ﺍﻟﺘﻘﻨﻴﺔ ﻭﺍﻟﻔﻨﻴﺔ‪.‬‬ ‫• ﻓﻤﺜﻼ ﰱ ﳎﺎﻻﺕ ﺍﻟﺘﻨﻔﻴﺬ ﻭﺍﻟﺘﺼﻨﻴﻊ ﻓﺈﻥ ﺍﳌﻬﻨﺪﺳﲔ ﻳﻘﻮﻣﻮﺍ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﳌـﻮﺍﺩ ﺍﳌﺨﺘﻠﻔـﺔ ﰱ ﻋﻤـﻞ‬ ‫ﺍﳌﻨﺸﺄﺕ ﺍﳌﺨﺘﻠﻔﺔ ﺃﻭ ﺗﺼﻨﻴﻊ ﺍﳌﻜﻴﻨﺔ ﺍﳌﺨﺘﻠﻔﺔ ﲢﺖ ﻇﺮﻭﻑ ﺧﺎﺻﻪ ﻭﺑﻄﺮﻕ ﻣﻼﺋﻤﺔ‪ ،‬ﻭﺃﻳﻀﺎ ﺑﺎﻟﻨﺴﺒﺔ‬ ‫ﻷﻋﻤﺎﻝ ﺍﻟﺘﺸﻐﻴﻞ ﻭﺍﻟﺼﻴﺎﻧﺔ ﻭﺍﳌﺒﻴﻌﺎﺕ ﻓﺈﻥ ﺍﳌﻬﻨﺪﺱ ﻳﻜﻮﻥ ﻋﻠﻰ ﻋﻼﻗﺔ ﻣﺒﺎﺷﺮﺓ ﺑﺎﺳـﺘﺨﺪﺍﻡ ﺍﳌـﻮﺍﺩ‬ ‫ﺍﳍﻨﺪﺳﻴﺔ ﰱ ﻛﻞ ﺍﻷﻋﻤﺎﻝ ﺍﳌﻄﻠﻮﺑﺔ ﻭﻛﺬﻟﻚ ﰱ ﺃﻋﻤﺎﻝ ﺍﻟﺘﻔﺘﻴﺶ ﻭﺍﻻﺧﺘﺒﺎﺭ ﻓﺈﻥ ﺍﳌﻬﻨـﺪﺱ ﻳﻘـﻮﻡ‬ ‫ﺑﺎﺧﺘﺒﺎﺭ ﺍﳌﻮﺍﺩ ﻭﺗﻌﻴﲔ ﺧﻮﺍﺻﻬﺎ ﻭﻣﺪﻯ ﺻﻼﺣﻴﺘﻬﺎ ﻗﺒﻞ ﺍﺳﺘﺨﺪﻣﻬﺎ ﰱ ﺃﻯ ﻣﻦ ﺍﻷﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ‪.‬‬ ‫• ﻟﺬﻟﻚ ﻧﺮﻯ ﳑﺎ ﺗﻘﺪﻡ ﺃﻥ ﻟﻠﻤﻬﻨﺪﺱ ﺻﻠﺔ ﺭﺋﻴﺴﻴﺔ ﻣﺒﺎﺷﺮﺓ ﻣﻊ ﺍﳌﻮﺍﺩ ﲝﻴﺚ ﺃﻥ ﺍﳌﻬﻨﺪﺱ ﻳﻘﻮﻡ ﺑﺘﺤﻮﻳﻞ‬ ‫ﺍﳌﻮﺍﺩ ﺍﳋﺎﻡ ﺇﱃ ﻣﻨﺸﺂﺕ ﻣﺜﻞ ﺍﳌﺒﺎﱏ ﻭﺍﻟﻜﺒﺎﺭﻯ ﻭﺍﳌﺼﺎﻧﻊ ﻭﺍﻟﺴﻴﺎﺭﺍﺕ ﻭﺍﻟﺼﻮﺍﺭﻳﺦ ﻭﻏﲑ ﺫﻟـﻚ ﰱ‬ ‫ﲨﻴﻊ ﺍ‪‬ﺎﻻﺕ‪ ،‬ﻟﺬﻟﻚ ﻓﺈﻧﻪ ﳚﺐ ﻋﻠﻰ ﺍﳌﻬﻨﺪﺱ ﺃﻥ ﻳﻜﻮﻥ ﻋﻠﻰ ﺩﺭﺍﻳﺔ ﻭﻣﻌﺮﻓﺔ ﺗﺎﻣﺔ ﺑﺎﳌﻮﺍﺩ ﻭﺧﻮﺍﺻﻬﺎ‬ ‫ﺍﳌﺨﺘﻠﻔﺔ ﻭﻣﺪﻯ ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻸﻧﻮﺍﻉ ﺍﻷﲪﺎﻝ ﺍﳌﺨﺘﻠﻔﺔ ﻭﻛﺬﻟﻚ ﻣﺪﻯ ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻠﻌﻮﺍﻣﻞ ﺍﳌﻌﺮﺿﺔ ﳍـﺎ‬ ‫ﻣﻊ ﺍﻟﺰﻣﻦ‪ .‬ﻟﺬﻟﻚ ﻳﺘﻄﻠﺐ ﺩﺭﺍﺳﺔ ﺍﻟﻘﻮﺍﻋﺪ ﻭﺍﻟﻘﻮﺍﻧﲔ ﻭﺍﻟﻨﻈﺮﻳﺎﺕ ﺍﻟﱴ ﺗﺘﺤﻜﻢ ﰱ ﺍﺧﺘﻼﻑ ﻋﻤـﻞ‬ ‫ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻭﺧﻮﺍﺻﻬﺎ ﲢﺖ ﺗﺄﺛﲑ ﺍﻟﻌﻮﺍﻣﻞ ﺍﳌﺨﺘﻠﻔﺔ ﻭﺩﺭﺍﺳﺔ ﺗﻠﻚ ﺍﳌـﻮﺍﺩ ﺍﳍﻨﺪﺳـﻴﺔ ﺗﻄﺒﻴﻘﻴـﺎ‬ ‫ﻭﻋﻤﻠﻴﺎ‪ ،‬ﻭﻛﺬﻟﻚ ﺗﺘﻄﻠﺐ ﻣﺘﺎﺑﻌﺔ ﺍﻟﺒﺤﻮﺙ ﺍﻟﻌﻤﻠﻴﺔ ﺍﻟﱴ ﲡﺮﻯ ﻋﻠﻰ ﻋﻠﻢ ﺧﻮﺍﺹ ﻭﻣﻘﺎﻭﻣﺔ ﺍﳌـﻮﺍﺩ‬ ‫ﻭﺍﺧﺘﺒﺎﺭﺍ‪‬ﺎ ﻟﻜﻰ ﺗﺼﻞ ﺑﻨﺎ ﺇﱃ ﺣﻞ ﺃﻯ ﻣﺸﺎﻛﻞ ﺗﻘﺎﺑﻠﻨﺎ ﰱ ﺍﺳﺘﺨﺪﺍﻡ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻭﻣﻮﺍﻛﺒـﺔ ﺃﻯ‬ ‫ﺗﻄﻮﺭ ‪‬ﺬﺍ ﺍﻟﻌﻠﻢ ﳝﻜﻦ ﺍﺳﺘﺨﺪﺍﻣﻪ ﰱ ﺃﻯ ﻏﺮﺽ ﺇﻧﺸﺎﺋﻰ ﻳﺘﻤﺎﺷﻰ ﻣﻊ ﺍﻟﺘﻄﻮﺭ ﻭﺍﻟﺘﻘﺪﻡ ﺍﳍﺎﺋﻞ ﰱ ﻛﻞ‬ ‫ﺍ‪‬ﺎﻻﺕ‪.‬‬

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‫‪ 4=1‬‬

‫ﺍﳌﻘﺼﻮﺩ ﺑﺎﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﺃ‪‬ﺎ ﺍﳌﻮﺍﺩ ﺍﻟﱴ ﺗﺴﺘﺨﺪﻡ ﰱ ﺍﻷﻋﻤﺎﻝ ﻭﺍ‪‬ﺎﻻﺕ ﺍﳌﺨﺘﻠﻔﺔ ﺳﻮﺍﺀ ﻟﻠﻤﻨﺸﺂﺕ ﻣﺜﻞ‬ ‫ﺍﻷﺣﺠﺎﺭ ﻭﺍﻟﻄﻮﺏ ﻭﺍﳌﻮﺍﺩ ﺍﻷﲰﻨﺘﻴﺔ ﻭﺍﻟﺮﻛﺎﻡ ﺍﻟﻨﺎﻋﻢ ﻭﺍﳋﺸﻦ ﻭﺍﻷﺧـﺸﺎﺏ ﻭﺍﻟﺒﻼﺳـﺘﻚ ﻭﺍﳌﻌـﺎﺩﻥ‬ ‫ﻭﺍﻟﺰﺟﺎﺝ ﻭﺍﳌﻮﺍﺩ ﺍﻟﻌﺎﺯﻟﺔ……ﻭﻏﲑﻫﺎ ﻛﺬﻟﻚ ﺗﻠﻚ ﺍﳌﻮﺍﺩ ﺍﳌﺴﺘﺨﺪﻣﺔ ﰱ ﺍﻟﺼﻨﺎﻋﺔ ﻭﺍﳌﺎﻛﻴﻨـﺎﺕ ﻣﺜـﻞ‬ ‫ﺍﳊﺪﻳﺪ ﻭﺍﻟﻨﺤﺎﺱ ﻭﺍﻷﻟﻮﻣﻨﻴﻮﻡ … ﺍﱁ‪ ،‬ﺃﻭ ﺍﳌﻮﺍﺩ ﺍﳌﺴﺘﺨﺪﻣﺔ ﰱ ﺃﻋﻤﺎﻝ ﺍﻟﺼﻴﺎﻧﺔ ﻣﺜـﻞ ﻣـﻮﺍﺩ ﺍﻟﻄـﻼﺀ‬ ‫ﻭﺍﻟﺒﻮﻳﺎﺕ‪ ،‬ﻭﻛﺬﻟﻚ ﺍﳌﻮﺍﺩ ﺍﻟﱴ ﺗﺴﺘﺨﺪﻡ ﻟﺘﻮﻟﻴﺪ ﺍﻟﻄﺎﻗﺔ ﻣﺜﻞ ﺍﳌﺎﺀ ﻭﺍﳌﻮﺍﺩ ﺍﻟﺒﺘﺮﻭﻟﻴﺔ ﻭﻣﻮﺍﺩ ﺍﻟﻄﺎﻗﺔ ﺍﻟﺬﺭﻳﺔ‪.‬‬ ‫ﺗﻘﺴﻢ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﺣﺴﺐ ﺗﺼﻨﻴﻔﺎﺕ ﻣﺘﻌﺪﺩﺓ ﻛﻤﺎ ﻳﻠﻲ‪:‬‬ ‫ﺃ‪-‬‬

‫ﺗﻘﺴﻴﻢ ﺍﳌﻮﺍﺩ ﺣﺴﺐ ﻃﺒﻴﻌﺔ ﺗﺮﻛﻴﺒﻬﺎ‪.‬‬

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‫ﺗﻘﺴﻴﻢ ﺍﳌﻮﺍﺩ ﺣﺴﺐ ﻣﺼﺎﺩﺭ ﺍﳊﺼﻮﻝ ﻋﻠﻴﻬﺎ‪.‬‬

‫ﺟـ‪ -‬ﺗﻘﺴﻴﻢ ﺍﳌﻮﺍﺩ ﺣﺴﺐ ﺧﻮﺍﺻﻬﺎ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ‪.‬‬ ‫‪@ @Nbèjî×Šm@òÈîj@ky@…aì½a@áîÔm@@QMTMQ‬‬ ‫‪@ @òîã†È½a@…aì½a MQ‬‬ ‫• ﻣﻌﺎﺩﻥ ﺣﺪﻳﺪﻳﺔ‪ :‬ﻣﺜﻞ ﺍﳊﺪﻳﺪ ﺍﻟﺼﻠﺐ ﻭﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ ﻭﺍﳊﺪﻳﺪ ﺍﳌﻄﺎﻭﻉ‬ ‫• ﻣﻌﺎﺩﻥ ﻏﲑ ﺣﺪﻳﺪﻳﺔ‪ :‬ﻫﻰ ﻣﻌﺎﺩﻥ ﺛﻘﻴﻠﺔ ﻣﺜﻞ ﺍﻟﻨﺤﺎﺱ ﻭﺍﻟﻨﻴﻜﻞ ﻭﻣﻨﻬﺎ ﻣﻌﺎﺩﻥ ﺧﻔﻴﻔﺔ ﻣﺜﻞ ﺍﻷﻟﻮﻣﻨﻴـﻮﻡ‬ ‫ﻭﺍﳌﺎﻏﻨﺴﻴﻮﻡ ﻭﻣﻌﺎﺩﻥ ﻃﺮﻳﺔ ﻣﺜﻞ ﺍﻟﺼﻔﻴﺢ ﻭﺍﻟﺮﺻﺎﺹ‪.‬‬ ‫‪@ @òîã†È½a@Ë@…aì½a MR‬‬ ‫• ﻣﻮﺍﺩ ﺍﻟﺒﻨﺎﺀ‪ :‬ﻣﺜﻞ ﺍﻷﺣﺠﺎﺭ ﻭﺍﻟﻄﻮﺏ ﻭ ﺍﻟﺮﻛﺎﻡ ﻭﺍﳋﺮﺳﺎﻧﺔ ﻭﺍﻷﲰﻨﺘﻴﺎﺕ ﻭﺍﳉﺒﺲ ﻭﺍﻷﺧـﺸﺎﺏ…‬ ‫ﻭﻏﲑﻫﺎ‪.‬‬ ‫• ﻣﻮﺍﺩ ﻣﺘﻨﻮﻋﺔ‪ :‬ﻣﺜﻞ ﺍﳌﻄﺎﻁ ﻭﺍﻟﺒﻼﺳﺘﻴﻚ ﻭﺍﻟﻔﻮﻡ ﻭﺍﻟﺒﻮﻳﺎﺕ… ﺍﱁ‪.‬‬ ‫‪@ @òÓbĐÜÛ@ñ†Ûì½a@…aì½a MS‬‬ ‫• ﻣﺜﻞ ﺍﳌﺎﺀ ﻭﺍﻟﻔﺤﻢ ﻭﺍﳌﻮﺍﺩ ﺍﻟﺒﺘﺮﻭﻟﻴﺔ ﻭﺍﻟﻴﻮﺭﺍﻧﻴﻮﻡ… ﻭﻏﲑﻫﺎ‪.‬‬

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‫‪@ @@@bèîÜÇ@Þì–§a@‰…b–ß@ky@…aì½a@áîÔm@RMTMQ‬‬ ‫@@‬ ‫‪@ @òîÈîj@‰…b–ß@åß@…aìß MQ‬‬ ‫ﳝﻜﻦ ﺗﻘﺴﻢ ﺍﳌﻮﺍﺩ ﺍﻟﻄﺒﻴﻌﻴﺔ ﺇﱃ ﻣﻮﺍﺩ ﻃﺒﻴﻌﻴﺔ ﻟﻴﺲ ﻷﻯ ﻳﺪ ﺑﺸﺮﻳﺔ ﺩﺧﻞ ﰱ ﺗﻜﻮﻳﻨﻬﺎ ﺃﻭ ﺗﻐﲑ ﺧﻮﺍﺻـﻬﺎ‪،‬‬ ‫ﻭﻣﻮﺍﺩ ﻣﺴﺘﺨﻠﺼﺔ‬ ‫• ‪@ @òîÈîjĐÛa@…aì½a‬‬

‫ﻫﻰ ﺍﳌﻮﺍﺩ ﺍﻟﱴ ﺗﺴﺘﺨﺪﻡ ﺑﻨﻔﺲ ﺑﻨﻴﺎ‪‬ﺎ ﻭﺧﻮﺍﺻﻬﺎ ﻛﻤﺎ ﻫﻰ ﺑﺎﻟﻄﺒﻴﻌﻴﺔ ﻣﺜﻞ ﺍﻷﺣﺠـﺎﺭ ﻭﺍﻟﺮﻛـﺎﻡ‬ ‫ﺑﺄﻧﻮﺍﻋﻪ ﻭﺍﳌﻮﺍﺩ ﺍﻟﺒﺘﺮﻭﻟﻴﺔ ﻭﺍﻷﺧﺸﺎﺏ‪.‬‬ ‫• ‪@ @ò–Ü‚n½a@…aì½a‬‬

‫ﻫﻰ ﺍﳌﻮﺍﺩ ﺍﻟﱴ ﺗﺴﺘﺨﻠﺺ ﻭﻳﺘﻢ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﻣﻦ ﺍﳋﺎﻣﺎﺕ ﺍﻟﻄﺒﻴﻌﻴﺔ ﻣﺜﻞ ﺍﳊﺪﻳﺪ ﻭﺍﻟﻨﺤﺎﺱ ﻭﺑﻌﺾ‬ ‫ﺍﳌﻨﺘﺠﺎﺕ ﺍﻟﺒﺘﺮﻭﻟﻴﺔ ﻭﺍﻟﺬﻫﺐ ﻭﺍﻷﻟﻮﻣﻨﻴﻮﻡ‪.‬‬ ‫‪@ @òîÇbä•@‰…b–ß@åß@…aìß MR‬‬ ‫ﻫﻰ ﺍﳌﻮﺍﺩ ﻭﻧﻈﺎﺋﺮﻫﺎ ﺍﻟﱴ ﻳﺘﻢ ﺗﺼﻨﻴﻔﻬﺎ ﻣﻦ ﺧﺎﻣﺎﺕ ﻃﺒﻴﻌﻴﺔ ﺃﻭ ﺧﺎﻣﺎﺕ ﻣﺼﻨﻌﺔ ﻭﳎﻬـﺰﺓ ﰱ ﺍﳌﻌﺎﻣـﻞ ﺃﻭ‬ ‫ﺍﳌﺼﺎﻧﻊ ﺑﻐﺮﺽ ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﻣﻮﺍﺩ ﻫﻨﺪﺳﻴﺔ ﻣﺼﻨﻌﺔ ﺫﺍﺕ ﺧﻮﺍﺹ ﻣﻌﻴﻨﺔ ﺗﻼﺋﻢ ﺍﻟﻌﻤﻞ ﺍﳌـﺼﻤﻤﺔ ﻣـﻦ‬ ‫ﺃﺟﻠﻪ‪ ،‬ﻣﺜﻞ ﻣﻮﺍﺩ ﺍﻟﻄﻼﺀ ﻭﻣﻮﺍﺩ ﺍﻟﻌﺰﻝ ﻭﺍﻟﻄﻮﺏ ﻭﺳﺒﺎﺋﻚ ﺍﳌﻌﺎﺩﺍﻥ ﻭ ﺍﻷﲰﻨﺖ……ﻭﻏﲑﻫﺎ‪.‬‬ ‫‪@ @òîÇbä–Ûaë@òî†äa@ÞbàÇþa@pbÐÜ«@åß@…aìß MS‬‬ ‫ﻫﻰ ﺍﳌﻮﺍﺩ ﺍﻟﱴ ﺗﻨﺘﺞ ﻭﲣﺘﻠﻒ ﺑﺸﻜﻞ ﺛﺎﻧﻮﻯ ﻣﻦ ﻣﺮﺍﺣﻞ ﺗﺼﻨﻴﻊ ﺍﻷﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ ﻭﺍﻟﺼﻨﺎﻋﻴﺔ ﻣﺜﻞ ﺧﺒﺚ‬ ‫ﺍﻷﻓﺮﺍﻥ ﻭﻧﻮﺍﺗﺞ ﺍﻻﺣﺘﺮﺍﻕ ﻭﺍﳌﺨﻠﻔﺎﺕ ﺍﻟﺒﺘﺮﻭﻟﻴﺔ ﻭﳐﻠﻔﺎﺕ ﺃﻋﻤﺎﻝ ﺍﳌﺒﺎﱏ ﻣﻦ ﺍﻟﻜﻮﺏ ﻭﺑﻼﻁ ﻭﺳﲑﺍﻣﻴﻚ‪،‬‬ ‫ﻭﺗﻠﻚ ﺍﳌﺨﻠﻔﺎﺕ ﻛﻠﻬﺎ ﳝﻜﻦ ﺍﺳﺘﺨﺪﻣﻬﺎ ﰱ ﺃﻋﻤﺎﻝ ﻫﻨﺪﺳﻴﺔ ﺍﺧﺮﻯ ﻣﺜﻞ ﺻﻨﺎﻋﺔ ﺍﻷﲰﻨـﺖ ﺍﳊﺪﻳـﺪﻯ‬ ‫ﻭﺃﻋﻤﺎﻝ ﺍﻟﻌﺰﻝ ﻭﺑﻌﺾ ﺃﻧﻮﺍﻉ ﻣﻦ ﺍﻟﻄﻮﺏ ﻭﺍﳋﺮﺳﺎﻧﺎﺕ…ﺍﱁ‬ ‫‪@ @òîØîãbØî½a@bè•aì@ky@…aì½a@áîÔm@@SMTMQ‬‬ ‫ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻣﻦ ﺃﻫﻢ ﺍﳋﻮﺍﺹ ﺍﻟﱴ ﺗﺪﺭﺱ ﺳﻠﻮﻙ ﺍﳌﻮﺍﺩ ﻭﺧﻮﺍﺻﻬﺎ ﻟﺬﻟﻚ ﳝﻜﻦ ﺗﻘﺴﻴﻢ ﺍﳌـﻮﺍﺩ‬ ‫ﳍﻨﺪﺳﻴﺔ ﻣﻦ ﺣﻴﺚ ﺧﻮﺍﺻﻬﺎ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﺇﱃ ﻣﻮﺍﺩ ﻣﻄﻴﻠﺔ ﻭﻣﻮﺍﺩ ﻧﺼﻒ ﻣﻄﻴﻠﺔ ﻭﻣﻮﺍﺩ ﻗﺼﻔﺔ‪.‬‬

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‫‪@ @òÜîĐ½a@…aì½a @NQ‬‬ ‫ﻫﻰ ﺍﳌﻮﺍﺩ ﺍﻟﱴ ﻳﺘﻐﲑ ﺷﻜﻠﻬﺎ ﺃﻭ ﳝﻜﻦ ﺃﻥ ﳛﺪﺙ ‪‬ﺎ ﺍﺳﺘﻄﺎﻟﺔ ﺑﺘﺄﺛﲑ ﺍﻷﲪﺎﻝ ﺍﳌﺨﺘﻠﻔﺔ ﺍﻟﱴ ﺗـﺆﺛﺮ ﻋﻠﻴﻬـﺎ‬ ‫ﻭﺗﻜﻮﻥ ﺧﺎﺻﻴﺔ ﺍﳌﺮﻭﻧﺔ ﻭﺍﳌﻤﻄﻮﻟﻴﺔ ‪‬ﺎ ﻋﺎﻟﻴﺔ ﻭﻛﺬﻟﻚ ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻠﺸﺪ ﻋﺎﻟﻴﺔ ﻣﺜـﻞ ﺍﳊﺪﻳـﺪ ﺍﳌﻄـﺎﻭﻉ‬ ‫ﻭﺍﻷﻟﻮﻣﻨﻴﻮﻡ…ﻭﻏﲑﻫﺎ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ‪.‬‬ ‫‪@ @òÐ–ÔÛa@…aì½a NR‬‬ ‫ﻫﻰ ﺍﳌﻮﺍﺩ ﺍﻟﱴ ﺗﻜﻮﻥ ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻠﺸﺪ ﺿﻌﻴﻔﺔ ﻭﻻ ﺗﻘﺎﻭﻡ ﺃﲪﺎﻝ ﺍﻟﺼﺪﻡ ﻭﻟﻜﻦ ﺗﺘﺤﺴﻦ ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻠﻀﻐﻂ‬ ‫ﺑﺸﻜﻞ ﻣﻨﺎﺳﺐ ﻣﺜﻞ ﺍﻟﻄﻮﺏ ﻭﺍﻷﺣﺠﺎﺭ ﻭﺍﳋﺮﺳﺎﻧﺔ ﻭﺍﻟﺰﺟﺎﺝ ﻭﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ… ﻭﻏﲑﻫﺎ ﻣـﻦ ﺍﳌـﻮﺍﺩ‬ ‫ﺍﳌﻌﺪﻧﻴﺔ ﻭﺍﻟﻐﲑ ﻣﻌﺪﻧﻴﺔ‪.‬‬ ‫‪@ @@òÜîĐß@Ñ–äÛa@…aì½a NS‬‬ ‫ﻫﻰ ﺍﳌﻮﺍﺩ ﺍﻟﱴ ﺧﻮﺍﺻﻬﺎ ﲡﻤﻊ ﺑﲔ ﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﺍﳌﻄﻴﻠﺔ ﻣﻦ ﺣﻴﺚ ﻗﺪﺭ‪‬ﺎ ﻋﻠﻰ ﺍﳌﻤﻄﻮﻟﻴﺔ ﺑﺪﺭﺟﺔ ﺃﻗـﻞ‬ ‫ﻭﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﺑﺘﺤﺴﲔ ﻇﺎﻫﺮ ﰱ ﺧﻮﺍﺹ ﺍﳌﺮﻭﻧﺔ‪ .‬ﻭﻫﺬﻩ ﺍﳌﻮﺍﺩ ﻫﻰ ﺍﻟﺼﻠﺐ ﺍﻟﻜﺮﺑﻮﱏ ﻭﺍﻟﻨﺤﺎﺱ‬ ‫ﺍﻷﺻﻔﺮ‪.‬‬ ‫‪ " 5-1‬‬

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‫ﺍﺧﺘﻴﺎﺭ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻫﻮ ﻗﻴﺎﺱ ﻣﺪﻯ ﺻﻼﺣﻴﺔ ﺍﺳﺘﺨﺪﺍﻡ ﺍﳌﻮﺍﺩ ﻻﺳﺘﻌﻤﺎﳍﺎ ﰱ ﺍﻷﻏﺮﺍﺽ ﺍﳌﺘﻨﻮﻋـﺔ‬ ‫ﺍﳌﻌﻴﻨﺔ‪ .‬ﻭﻋﻠﻴﻪ ﳒﺪ ﺃﻧﻪ ﻣﻦ ﺃﻫﻢ ﺃﻏﺮﺍﺽ ﺍﺧﺘﻴﺎﺭ ﺍﳌﻮﺍﺩ ﻫﻮ ﺍﳌﺴﺎﻋﺪﺓ ﻋﻠﻰ ﺇﻇﻬﺎﺭ ﻣـﺪﻯ ﻣﻘﺎﻭﻣـﺔ ﻭ‬ ‫ﺍﺣﺘﻤﺎﻝ ﺍﳌﻮﺍﺩ ﲢﺖ ﻇﺮﻭﻑ ﺍﻟﻌﻤﻞ ﺍﳌﺨﺘﻠﻔﺔ ﻷﻯ ﻋﻤﻞ ﻫﻨﺪﺳﻰ ﻣﻄﻠﻮﺑﺔ ﻷﺟﻠﻪ‪.‬‬ ‫ﻣﻦ ﻫﻨﺎ ﳚﺐ ﺃﻥ ﻧﺄﺧﺬ ﰱ ﺍﻻﻋﺘﺒﺎﺭ ﺃﻥ ﺍﳌﻮﺍﺩ ﺍﳌﺨﺘﺎﺭﺓ ﺍﻟﱴ ﺗﺴﺘﺨﺪﻡ ﺑﺸﻜﻞ ﻣﻨﺎﺳﺐ ﻭﺟﻴﺪ ﻭﻧﺴﺘﻔﻴﺪ‬ ‫ﻣﻦ ﳑﻴﺰﺍﺕ ﺧﻮﺍﺻﻬﺎ ﺑﺪﻭﻥ ﺃﻯ ﺇﳘﺎﻝ ﺃﻭ ﺳﻮﺀ ﺍﺳﺘﺨﺪﺍﻡ ﳍﺎ ﻭﻛﺬﻟﻚ ﻣﺮﺍﺣﻞ ﺍﻟﺘﺼﻤﻴﻢ ﺍﳌﻨﺎﺳﺐ ﻣﻌﹰﺎ‬ ‫ﻳﺆﻛﺪﺍﻥ ﺳﻼﻣﺔ ﺍﻟﻌﻤﻞ ﺍﳌﻄﻠﻮﺏ ﺗﻨﻔﻴﺬﻩ‪ .‬ﻭﻫﻨﺎﻙ ﻣﺼﺪﺭﺍﻥ ﺃﺳﺎﺳﻴﺎﻥ ﳛﺼﻞ ﻣﻨﻬﻤﺎ ﺍﳌﻬﻨـﺪﺱ ﻋﻠـﻰ‬ ‫ﺍﻟﺒﻴﺎﻧﺎﺕ ﺍﻟﻼﺯﻣﺔ ﻟﻺﺧﺘﻴﺎﺭ ﺍﻷﻣﺜﻞ ﻟﻠﻤﻮﺍﺩ ﻭﳘﺎ‪:‬‬ ‫ﺍﻟﺘﻘﺎﺭﻳﺮ ﺍﻟﱴ ﺗﺒﲔ ﻣﺪﻯ ﻛﻔﺎﺀﺓ ﺍﺳﺘﺨﺪﺍﻡ ﺍﳌﻮﺍﺩ ﻋﻨﺪ ﺍﻟﺘﻨﻔﻴﺬ‪.‬‬ ‫ﻧﺘﺎﺋﺞ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﱴ ﺍﺟﺮﻳﺖ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﳌﻌﺮﻓﺔ ﻭﲢﺪﻳﺪ ﺧﻮﺍﺻﻬﺎ ﺣﱴ ﻳﺘﻤﻜﻦ ﺍﳌـﺼﻤﻢ‬ ‫ﻣﻦ ﺇﻋﺪﺍﺩ ﻣﻮﺍﺻﻔﺎ‪‬ﺎ‪.‬‬ ‫ﻟﻜﻰ ﻳﺘﻤﺜﻞ ﺗﺼﻤﻴﻢ ﺃﻯ ﻣﻨﺸﺄ ﺇﱃ ﺑﻨﺎﺀ ﻗﺎﺋﻢ‪ ،‬ﺑﺄﻧﻪ ﳚﺐ ﻋﻠﻰ ﺍﳌﻨﻔﺬ ﺃﻥ ﳜﺘﺎﺭ ﺍﳌﻮﺍﺩ ﺍﳌﺘﻨﻮﻋﺔ ﺍﳌﻄﻠﻮﺑـﺔ‬ ‫ﺑﺸﻜﻞ ﻳﺴﻬﻞ ﺍﳊﺼﻮﻝ ﻋﻠﻴﻬﺎ ﻣﻦ ﺍﻷﻧﻮﺍﻉ ﺍﻟﱴ ﻳﻘﺼﺪﻫﺎ ﺍﳌﺼﻤﻢ‪ ،‬ﰒ ﳒﺮﻯ ﺍﻹﺧﺘﺒﺎﺭﺍﺕ ﺍﳌﻄﻠﻮﺑـﺔ‬ ‫ﻟﺘﺤﺪﻳﺪ ﻧﻮﻉ ﺍﳌﻮﺍﺩ ﺍﻟﻼﺯﻣﺔ‪ .‬ﻭﻋﻠﻴﺔ ﳚﺐ ﻧﺄﺧﺬ ﺍﻻﻋﺘﺒﺎﺭ ﺑﻌﺾ ﺍﻻﺣﺘﻴﺎﺟﺎﺕ ﻋﻨﺪ ﺍﺧﺘﺒﺎﺭ ﺍﳌﻮﺍﺩ ﻛﻤﺎ‬ ‫ﻳﻠﻰ‪:‬‬ ‫‪٦‬‬


‫‪ -١‬ﺃﻧﻮﺍﻉ ﺍﳌﻮﺍﺩ ﺍﻟﱴ ﳝﻜﻦ ﺍﳊﺼﻮﻝ ﻋﻠﻴﻬﺎ‪.‬‬ ‫‪ -٢‬ﺍﳋﻮﺍﺹ ﺍﳌﻤﻴﺰﺓ ﻟﻠﻤﻮﺍﺩ ﺍﳌﺘﻨﻮﻋﺔ‪.‬‬ ‫‪ -٣‬ﺍﻻﺳﺘﺨﺪﺍﻣﺎﺕ ﺍﳌﻄﻠﻮﺑﺔ ﻣﻦ ﺍﳌﻮﺍﺩ‪.‬‬ ‫‪ -٤‬ﻃﺮﻕ ﺻﻨﺎﻋﺔ ﺍﳌﻮﺍﺩ ﺍﳌﺨﺘﻠﻔﺔ ﻭﺗﺄﺛﲑﻫﺎ ﻋﻠﻰ ﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ‪.‬‬ ‫‪ -٥‬ﺃﺳﻠﻮﺏ ﻭﺿﻊ ﺍﳌﻮﺍﺻﻔﺎﺕ ﻟﻠﻤﻮﺍﺩ ﻭﻣﺪﻯ ﻣﻼﺋﻤﺘﻬﺎ ﳌﺮﺍﺣﻞ ﺍﻟﺘﻨﻔﻴﺬ‪.‬‬ ‫‪ -٦‬ﻃﺮﻕ ﺍﻻﺧﺘﻴﺎﺭ ﺍﻷﻣﺜﻞ ﻭ ﺍﻟﻔﺤﺺ ﺍﳌﻄﻠﻮﺏ ﻭﻣﺪﻯ ﺩﻻﻟﺘﻬﺎ ﻋﻠﻰ ﺗﻘﺮﻳﺮ ﻭﻗﻴﺎﺱ ﺍﳋﺎﺻﻴﺔ ﺍﳌﻄﻠﻮﺑﺔ‪.‬‬ ‫ﻭﻳﺒﲔ ﺍﻟﺸﻜﻞ )‪ (١-١‬ﺍﳌﺘﻄﻠﺒﺎﺕ ﺍﳌﺨﺘﻠﻔﺔ ﺍﻟﱴ ﺗﺘﺤﻜﻢ ﰱ ﺍﺧﺘﻴﺎﺭ ﺍﳌﻮﺍﺩ‪.‬‬

‫‪" #‬‬ ‫‪@ @âa†‚nüa@pbjÜĐnß‬‬

‫‪@ @Éîä–nÛa@pbjÜĐnß‬‬

‫‪@ @òí…b–nÓa@pbjÜĐnß‬‬

‫‪ -‬ﺍﳌﻘﺎﻭﻣﺔ‬

‫‪ -‬ﺳﻬﻮﻝ ﺍﻟﺘﺠﻤﻴﻊ‬

‫‪ -‬ﺗﻜﺎﻟﻴﻒ ﺍﳌﻮﺍﺩ‬

‫‪ -‬ﺍﻟﻮﺯﻥ ﺍﳌﻨﺎﺳﺐ‬

‫‪ -‬ﻗﺎﺑﻠﻴﺔ ﺍﻟﻄﺮﻕ‬

‫‪ -‬ﺗﻜﺎﻟﻴﻒ ﺍﻟﺼﺐ ﺃﻭ ﺍﻟﺘﺸﻐﻴﻞ‬

‫‪ -‬ﺗﻮﺍﻓﺮ ﺍﳌﺎﺩﺓ‬

‫‪ -‬ﻗﺎﺑﻠﻴﺔ ﺍﻟﺘﺸﻐﻴﻞ‬

‫‪ -‬ﺗﻜﺎﻟﻴﻒ ﺍﻟﺘﺠﻤﻴﻊ‬

‫‪ -‬ﺍﳌﺮﻭﻧﺔ‬

‫ـﺔ ‪ -‬ﺗﻜﺎﻟﻴﻒ ﺍﻟﺘﺸﻐﻴﻞ ﺑﺎﳌﺎﻛﻴﻨﺎﺕ‬ ‫ـﻊ ﺍﳌﻌﺎﻣﻠـ‬ ‫ـﺎﺭﺏ ﻣـ‬ ‫ ﺍﻟﺘﺠـ‬‫ﺍﳊﺮﺍﺭﻳﺔ‬

‫ ﺍﻟﺼﻼﺩﺓ‬‫‪ -‬ﺍﳋﻮﺍﺹ ﺍﳌﻐﻨﺎﻃﻴﺴﻴﺔ‬

‫‪ -‬ﻗﺎﺑﻠﻴﺔ ﺍﻟﺼﺐ‬

‫ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻜﻼﻝ‬‫ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺰﺣﻒ‬‫ ﻣﻘﺎﻭﻣﺔ ﺍﳊﺮﺍﺭﺓ‬‫ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺘﺄﻛﻞ‬‫ ﺍﻟﺘﻤﺪﺩ ﺍﳊﺮﺍﺭﻯ‬‫ ﺍﻟﺘﻮﺻﻴﻞ ﺍﳊﺮﺍﺭﻯ‬‫‘‪@ @…aì½a@‰bîna@óÏ@áØznm@ónÛa@òÐÜn‚½a@pbjÜĐn½a@HQMQI@ÝØ‬‬

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‫ﻛﻤﺎ ﻳﺒﲔ ﺟﺪﻭﻝ )‪ (١-١‬ﺃﻣﺜﻠﺔ ﻋﺎﻣﺔ ﻋﻦ ﺍﻷﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﺘﻨﻮﻋﺔ ﻭﺍﳋﺎﺻـﻴﺔ ﺍﳌﻄﻠﻮﺑـﺔ ﰱ ﺍﳌـﺎﺩﺓ‬ ‫ﻭﺍﳌﻨﺎﺳﺒﺔ ﳍﺬﻩ ﺍﻷﻋﻤﺎﻝ‪ ،‬ﺣﱴ ﻧﺘﻤﻜﻦ ﻣﻦ ﺍﺧﺘﻴﺎﺭ ﺍﳌﺎﺩﺓ ﺍﳌﻨﺎﺳﺒﺔ ﳍﺬﺍ ﺍﻟﻐﺮﺽ‪.‬‬ ‫‪@ @òiìÜĐ½a@òî†äa@ÞbàÇÿÛ@òjbä½a@òî†äa@…aì½a@ãì@åÇ@òÜrßc@HQMQI@Þë†u‬‬ ‫‪ $‬‬ ‫‬‫‬‫‬‫‬‫‬‫‬‫‪-‬‬

‫‪@ @@ÁÌšÛa@òßëbÔß‬‬ ‫‪@ @@ŠØÛa@òßëbÔß‬‬ ‫‪@ @@ñ‰ŠØn½a@Þb»þa@òßëbÔß‬‬ ‫‪@ @@òÓbĐÛa@˜b–nßa@óÜÇ@òßëbÔß‬‬ ‫‪@ @ÊbÈ‘üa@òßëbÔß‬‬ ‫‪@ @ôÛaë@Ý×fnÛa@òßëbÔß‬‬ ‫‪@ @æ‹ìÛa@òÐ‬‬

‫('& ‪%‬‬ ‫‬‫‬‫‬‫‬‫‬‫‬‫‪-‬‬

‫‪@ @@òîãbŠä@ñ†àÇþa‬‬ ‫‪@ @@ÝýÛa‬‬ ‫‪@ @‰aë†Ûa@‰ìa@kîšÓ‬‬ ‫‪@ @@pbíbîÛa‬‬ ‫‪@ @@˜b•ŠÛa@åß@òÇìä–½a@Áöaì§a‬‬ ‫‪@ @‹bØm‰üa@†ÇaìÓ‬‬ ‫‪@ @@paŠöbĐÛa@õaŒuc‬‬

‫‪ ( '( $ 6-1‬‬

‫ﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﻫﻲ ﺍﳌﻘﺎﻳﻴﺲ ﻭﺍﳌﻌﺎﻳﲑ ﺍﶈﺪﺩﺓ ﺍﻟﱴ ﺗﺼﻒ ﺟﻮﺩﺓ ﺍﳌﻮﺍﺩ‪ ،‬ﻭﺗﻔﻴﺪ ﺍﳋﻮﺍﺹ ﰱ ﺍﻋﺘﺒﺎﺭﻫﺎ ﺃ‪‬ـﺎ‬ ‫ﺍﻷﺳﺎﺱ ﺍﻟﺬﻱ ﻳﻀﻊ ﺑﻪ ﺍﳌﻬﻨﺪﺱ ﺍﳌﺼﻤﻢ ﺍﺣﺘﻴﺎﺟﺎﺗﻪ ﻟﻠﻤﺎﺩﺓ ﻭﺍﺧﺘﻴﺎﺭ ﺍﻧـﺴﺒﻬﺎ ﰱ ﺍﻷﻋﻤـﺎﻝ ﺍﳍﻨﺪﺳـﻴﺔ‬ ‫ﺍﳌﺨﺘﻠﻔﺔ‪ .‬ﻭﻟﻜﻰ ﺗﻜﻮﻥ ﻋﻠﻰ ﺩﺭﺍﻳﺔ ﻭﻣﻌﺮﻓﺔ ﺩﻗﻴﻘﺔ ﲟﺎﺩﺓ ﻣﻦ ﺍﳌﻮﺍﺩ ﳚﺐ ﻋﻠﻴﻨﺎ ﺗﻌﻴﲔ ﺧﻮﺍﺹ ﺗﻠﻚ ﺍﳌـﻮﺍﺩ‬ ‫ﲢﺖ ﺃﻯ ﻇﺮﻭﻑ ﻭﺫﻟﻚ ﻟﻀﻤﺎﻥ ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﻛﺎﻓﺔ ﺍﻟﺒﻴﺎﻧﺎﺕ ﻭﺍﳌﻌﻠﻮﻣﺎﺕ ﻋﻦ ﻫﺬﻩ ﺍﳋﻮﺍﺹ ﻭﺍﻟﱴ ﺗﺆﺛﺮ‬ ‫ﺑﺸﻜﻞ ﻣﺒﺎﺷﺮ ﻋﻠﻰ ﻗﻴﻤﺔ ﺍﻷﻋﻤﺎﻝ ﺍﳌﺴﺘﺨﺪﻡ ﻓﻴﻬﺎ ﻫﺬﻩ ﺍﳌﻮﺍﺩ ﻓﻨﻴﺎ ﻭﺍﻗﺘﺼﺎﺩﻳﺎ‪ .‬ﻭﻣﻦ ﻫﻨﺎ ﳚﺐ ﺃﻥ ﻧﺘﻌﺮﻑ‬ ‫ﻋﻠﻰ ﺍﳋﻮﺍﺹ ﺍﳌﻤﻴﺰﺓ ﻟﻠﻤﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ‪:‬‬ ‫‪@ @òîÈîjĐÛa@ãìä MQ‬‬ ‫ﺗﺘﻤﻴﺰ ﺍﳋﻮﺍﺹ ﺍﻟﻄﺒﻴﻌﻴﺔ ﻟﻠﻤﻮﺍﺩ ﲟﻌﺮﻓﺔ ﺧﻮﺍﺻﻬﺎ ﻋﻦ ﺍﻷﺑﻌﺎﺩ ﻭﺍﻟﻠﻮﻥ ﻭﺍﻟﺸﻜﻞ ﻭﺍﻟﻮﺯﻥ ﺍﻟﻨﻮﻋﻰ ﻭﺍﻟـﻮﺯﻥ‬ ‫ﺍﳊﺠﻤﻰ ﻭﺍﳌﺴﺎﻣﻴﺔ ﻭﺍﻟﺘﺮﻛﻴﺐ ﺍﳉﺰﻳﺌﻰ ﻭﺍﻟﺒﻠﻮﺭﻯ … ﺍﱁ‬ ‫‪@ @òîöbîàîØÛa@ãìä MR‬‬ ‫ﺗﺘﻌﻠﻖ ﺍﳋﻮﺍﺹ ﺍﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﺑﺎﻟﺘﺮﻛﻴﺐ ﺍﻟﻜﻴﻤﻴﺎﺋﻰ ﻟﻠﻤﺎﺩﺓ ﻭﺗﻌﻴﲔ ﺍﻷﺱ ﺍﳍﻴـﺪﺭﻭﺟﲔ ﳌﻌﺮﻓـﺔ ﺍﻟﻘﺎﻋﺪﻳـﺔ‬ ‫ﻭﺍﳊﺎﻣﻀﻴﺔ‪ ،‬ﻭﻣﻌﺮﻓﺔ ﺃﻳﻀﺎ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺘﺂﻛﻞ ﺑﺎﻟﺼﺪﺃ‪ ،‬ﲢﺪﻳﺪ ﻧﺴﺐ ﺍﳌﻮﺍﺩ ﺍﻟﻐﺮﻳﺒﺔ ﻭﺍﻟﺸﻮﺍﺋﺐ ﺍﳌﻮﺟﻮﺩﺓ ﰱ‬ ‫ﺍﳌﻮﺍﺩ ﻟﻠﺤﻜﻢ ﻋﻠﻰ ﺿﺒﻂ ﺟﻮﺩﺓ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ‪.‬‬ ‫‪٨‬‬


‫‪@ @òí‰aŠ§a@ãìä MS‬‬ ‫ﻫﻰ ﺍﳋﻮﺍﺹ ﺍﻟﱴ ﺗﻮﺿﺢ ﺗﺄﺛﲑ ﺍﳊﺮﺍﺭﺓ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﻣﻨﻬﺎ ﲢﺪﻳﺪ ﺍﳊﺮﺍﺭﺓ ﺍﻟﻨﻮﻋﻴﺔ ﻭﺍﻟﺘﻮﺻـﻴﻞ ﺍﳊـﺮﺍﺭﻯ‬ ‫ﻭﻣﻌﺎﻣﻼﺕ ﺍﻟﺘﻤﺪﺩ ﻭﺍﻻﻧﻜﻤﺎﺵ ﻣﻦ ﺍﻟﺘﺄﺛﲑ ﺍﳊﺮﺍﺭﻯ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﻭﺍﻟﻌﻴﻨﺎﺕ‪.‬‬ ‫‪@ @òîiŠèØÛa@ãìä MT‬‬ ‫ﺍﳋﻮﺍﺹ ﺍﻟﻜﻬﺮﺑﻴﺔ ﺗﺮﺗﺒﻂ ﺑﺘﻌﻴﲔ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻜﻬﺮﺑﻴﺔ ﻟﻠﻤﻮﺍﺩ ﻭﻛﺬﻟﻚ ﻣﻌﺮﻓﺔ ﺍﻟﺘﻮﺻﻴﻞ ﻭﺍﻟﻌﺰﻝ ﺍﻟﻜﻬﺮﺑﺎﺋﻰ‪.‬‬ ‫‪@ @òîîbäÌ½a@ãìä MU‬‬ ‫ﻣﻦ ﺃﻫﻢ ﺍﳋﻮﺍﺹ ﺍﳌﻐﻨﺎﻃﻴﺴﻴﺔ ﻫﻰ ﻣﻌﺮﻓﺔ ﺍﻟﻨﻔﺎﺫ ﺍﳌﻐﻨﺎﻃﻴﺴﻰ ﻟﻠﻤﻮﺍﺩ‪ ،‬ﻭﻗﻴﺎﺱ ﺍﻟﻌﺰﻝ ﺍﳌﻐﻨﺎﻃﻴﺴﻰ ﻭﺩﺭﺟـﺔ‬ ‫ﺍﻟﺘﺄﺛﲑ ﺑﺎ‪‬ﺎﻻﺕ ﺍﳌﻐﻨﺎﻃﻴﺴﻴﺔ ﺍﶈﻴﻄﺔ‪.‬‬ ‫‪@ @òîöìšÛa@ãìä MV‬‬ ‫ﺗﻌﺘﻤﺪ ﻫﺬﻩ ﺍﳋﻮﺍﺹ ﻋﻠﻰ ﺗﺄﺛﲑ ﺍﻟﻀﻮﺀ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﻭﻣﻦ ﻫﺬﻩ ﺍﳋﻮﺍﺹ ﺗﻌﻴﲔ ﺩﺭﺟﺔ ﺍﻧﻜـﺴﺎﺭ ﺍﻟـﻀﻮﺀ‬ ‫ﻭﺍﻣﺘﺼﺎﺹ ﻭﺍﻧﻌﻜﺎﺱ ﺍﻟﻀﻮﺀ ﻭﺩﺭﺟﺔ ﺍﻟﻠﻮﻥ‪ ،‬ﻭﳝﻜﻦ ﲢﺪﻳﺪ ﺗﻠﻚ ﺍﳋﻮﺍﺹ ﻭﺍﻟﱴ ﺗﺆﺛﺮ ﺑﺸﻜﻞ ﻣﺒﺎﺷﺮ ﻋﻠﻰ‬ ‫ﺍﺧﺘﻴﺎﺭ ﺍﳌﻮﺍﺩ ﺍﻟﻼﺯﻣﺔ ﻟﻠﻌﻤﻞ ﺍﳍﻨﺪﺳﻰ ﺍﳌﻄﻠﻮﺏ ﻭﺧﺎﺻﺔ ﰱ ﺃﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﻌﻤﺎﺭﻳﺔ‪.‬‬ ‫‪@ @@òîmì–Ûa@ãìä MW‬‬ ‫ﺍﳋﻮﺍﺹ ﺍﻟﺼﻮﺗﻴﺔ ﻟﻠﻤﻮﺍﺩ ﻣﺜﻞ ﺍﻟﺘﻮﺻﻴﻞ ﺍﻟﺼﻮﺗﻰ ﻭﺍﻻﻧﻌﻜﺎﺱ ﺍﻟﺼﻮﺗﻰ ﻭﺩﺭﺟﺔ ﻋﺰﻝ ﺍﻟﺼﻮﺕ ﻭﺩﺭﺟـﺔ‬ ‫ﻧﻔﺎﺫﻳﺔ ﺍﻟﺼﻮﺕ ﻭﺍﻟﺘﺮﺩﺩ ﻭﳍﺬﻩ ﺍﳋﻮﺍﺹ ﺃﳘﻴﺔ ﰱ ﳎﺎﻻﺕ ﺗﻄﺒﻴﻘﻴﺔ ﳐﺘﻠﻔﺔ‪.‬‬ ‫‪@ @@òîØîãbØî½a@ãìä MX‬‬ ‫ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻫﻰ ﺍﳋﻮﺍﺹ ﺍﻟﱴ ﺗﺘﻌﻠﻖ ﺑﺴﻠﻮﻙ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻋﻨﺪ ﺗﻌﺮﺿﻬﺎ ﻟﻸﲪـﺎﻝ ﺍﳌـﺆﺛﺮﺓ‬ ‫ﺍﳌﺨﺘﻠﻔﺔ ﺳﻮﺍﺀ ﻛﺎﻧﺖ ﻫﺬﻩ ﺍﻷﲪﺎﻝ ﺇﺳﺘﺎﺗﻴﻜﻴﺔ ﺃﻭ ﺩﻳﻨﺎﻣﻴﻜﻴﺔ ﺃﻭ ﻣﺘﻜﺮﺭﺓ‪ .‬ﻛﻤﺎ ﺃﻥ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴـﺔ‬ ‫ﺗﺴﺘﺨﺪﻡ ﻛﺄﺳﺎﺱ ﻟﻠﻤﻘﺎﺭﻧﺔ ﺑﲔ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ‪ .‬ﻭﻷﳘﻴﺔ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻠﻤﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ‬ ‫ﻓﺈﻧﻪ ﺳﻴﺘﻢ ﻓﺼﻠﻬﺎ ﻭﺳﺮﺩ ﺗﻮﺿﻴﺤﻬﺎ ﺑﺪﻗﺔ ﻋﺎﻟﻴﺔ ﻋﻠﻰ ﺣﺪﻩ ﻓﻴﻤﺎ ﻳﻠﻰ‪.‬‬ ‫‪ ( +,+ $ 7-1‬‬

‫ﻟﺘﻌﻴﲔ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻠﻤﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﳚﺐ ﺃﻥ ﺗﻜﻮﻥ ﻋﻠﻰ ﻣﻌﺮﻓﺔ ﺗﺎﻣﺔ ﺑﺄﻧﻮﺍﻉ ﻭﻃﺒﻴﻌﻴﺔ ﺍﻷﲪـﺎﻝ‬ ‫ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻗﺒﻞ ﺍﳋﻮﺽ ﰱ ﺍﻟﺘﻌﺮﻑ ﻋﻠﻰ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﺍﻟﺮﺋﻴـﺴﻴﺔ ﺍﻟـﱴ ﲤﻴـﺰ‬ ‫ﺻﻔﺎﺕ ﻭﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ‪.‬‬ ‫‪٩‬‬


‫‪&-"( . ,‬‬ ‫ﳝﻜﻦ ﺗﻘﺴﻴﻢ ﺍﻟﻄﺮﻕ ﺍﻟﱴ ﺗﺆﺛﺮ ‪‬ﺎ ﺍﻷﲪﺎﻝ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﺇﱃ ﺍﻷﻧﻮﺍﻉ ﺍﻵﺗﻴﺔ‪:‬‬ ‫‪@ @@óØîmbnüa@ÝîàznÛa MQ‬‬ ‫ﺍﳊﻤﻞ ﺍﻻﺳﺘﺎﺗﻴﻜﻰ ﻗﺪ ﻳﻜﻮﻥ ﻓﻴﻪ ﺗﺄﺛﲑ ﺍﳊﻤﻞ ﺑﻄﻴﺌﹰﺎ ﻣﺘﺰﺍﻳﺪﹰﺍ ﺃﻭ ﻣﺘﻨﺎﻗﺼﹰﺎ ﺗﺪﺭﳚﻴﹰﺎ ﺣﱴ ﻳﺼﻞ ﺇﱃ ﻗﻴﻤﺘـﻪ‬ ‫ﺍﻟﻘﺼﻮﻯ ﺃﻭ ﺍﻟﺪﻧﻴﺎ ﺑﺪﻭﻥ ﺣﺪﻭﺙ ﺃﻯ ﺃﲪﺎﻝ ﺻﺪﻡ ﺃﻭ ﺍﻫﺘﺰﺍﺯ ﻣﺜﻞ ﺃﲪﺎﻝ ﺍﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﺸﺪ ﺃﻭ ﺍﻟﻀﻐﻂ ﺃﻭ‬ ‫ﺍﻻﳓﻨﺎﺀ ﺃﻭ ﺍﻟﻘﺺ‪ ،‬ﺣﻴﺚ ﺃﻧﻪ ﲢﻤﻞ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﺑﺄﲪﺎﻝ ﺗﺰﺩﺍﺩ ﺗﺪﺭﳚﻴﺎ ﺑﺒﻂﺀ ﻭﲟﻌﺪﻻﺕ ﲢﻤﻴﻞ ﻣﻌﻠﻮﻣﺔ‬ ‫ﻃﺒﻘﺎ ﳌﻮﺍﺻﻔﺎﺕ ﺃﻯ ﻣﻦ ﺍﻹﺧﺘﺒﺎﺭﺍﺕ ﺣﱴ ﻳﺼﻞ ﺍﳊﻤﻞ ﺇﱃ ﻗﻴﻤﺘﻪ ﺍﻟﻘﺼﻮﻯ ﻭﳛﺪﺙ ﺍﻟﻜﺴﺮ ﺑﺎﻟﻌﻴﻨـﺎﺕ‪.‬‬ ‫ﻭﻗﺪ ﻳﻜﻮﻥ ﺍﳊﻤﻞ ﺍﻹﺳﺘﺎﺗﻴﻜﻰ ﺛﺎﺑﺖ ﺍﳌﻘﺪﺍﺭ ﻭﺍﻻﲡﺎﻩ ﻭﻃﺒﻴﻌﺔ ﻭﻣﻮﺿﻊ ﺍﻟﺘـﺄﺛﲑ ﻣﺜـﻞ ﺃﻭﺯﺍﻥ ﺍﻟﻌﻨﺎﺻـﺮ‬ ‫ﺍﻹﻧﺸﺎﺋﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ ﻭﻛﺬﻟﻚ ﺃﻯ ﺃﲪﺎﻝ ﺩﺍﺋﻤﺔ ﺳﺎﻛﻨﺔ ﻣﺆﺛﺮﺓ ﻋﻠﻴﻬﺎ‪ .‬ﻛﻤـﺎ ﺃﻥ ﺍﻟﺘﺤﻤﻴـﻞ ﺍﳌـﺴﺘﻤﺮ ﺍﻭ‬ ‫ﻼ ﺇﺳﺘﺎﺗﻴﻜﻴﺎ‪.‬‬ ‫ﺍﻟﺘﺤﻤﻴﻞ ﺍﻟﺪﺍﺋﻢ ﻣﺪﺓ ﻃﻮﻳﻠﺔ ﻣﻊ ﺍﻟﺰﻣﻦ ﺑﺪﻭﻥ ﺗﻐﻴﲑ ﰱ ﻃﺒﻴﻌﻴﺔ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻳﻌﺪ ﲢﻤﻴ ﹰ‬ ‫‪@ @óØîßbäí†Ûa@ÝîàznÛa MR‬‬ ‫ﺍﻟﺘﺤﻤﻴﻞ ﺍﻟﺪﻳﻨﺎﻣﻴﻜﻰ ﺗﻜﻮﻥ ﺍﻷﲪﻞ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﻣﺎ ﻫﻰ ﺇﻻ ﺃﲪﺎﻝ ﺍﻫﺘﺰﺍﺯ ﺃﻭ ﺃﲪﺎﻝ ﺻﺪﻡ ﻭﺗﻜﻮﻥ‬ ‫ﻣﺪﺓ ﺗﺄﺛﲑ ﻫﺬﻩ ﺍﻷﲪﺎﻝ ﻗﺼﲑﺓ ﻧﺴﺒﻴﹰﺎ‪ .‬ﻭﳜﺘﻠﻒ ﺍﻟﺘﺤﻤﻴﻞ ﺍﻟﺪﻳﻨﺎﻣﻴﻜﻰ ﻋﻦ ﺍﻟﺘﺤﻤﻴﻞ ﺍﻹﺳـﺘﺎﺗﻴﻜﻰ ﰱ ﺃﻥ‬ ‫ﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﻨﺎﺷﺌﺔ ﻋﻦ ﺍﻟﺘﺤﻤﻴﻞ ﺍﻟﺪﻳﻨﺎﻣﻴﻜﻰ ﺃﻋﻠﻰ ﺑﻜﺜﺮ ﻣﻦ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﻨﺎﲡﺔ ﻋﻦ ﺍﻟﺘﺄﺛﲑ ﺑﻨﻔﺲ ﻗﻴﻤﺔ‬ ‫ﺍﳊﻤﻞ ﻭﻟﻜﻦ ﲪﻞ ﺇﺳﺘﺎﺗﻴﻜﻰ‪ .‬ﻭﻳﻌﺮﻑ ﺍﳊﻤﻞ ﺍﻻﺳﺘﺎﺗﻴﻜﻰ ﺍﻟﺬﻯ ﻳﻌﻄﻰ ﻧﻔﺲ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﻨﺎﺷﺌﺔ ﻣـﻦ‬ ‫ﺍﳊﻤﻞ ﺍﻟﺪﻳﻨﺎﻣﻴﻜﻰ ﺑﺎﳊﻤﻞ ﺍﻻﺳﺘﺎﺗﻴﻜﻰ ﺍﳌﻜﺎﻓﺊ‪ .‬ﻭﻣﻦ ﺃﻣﺜﻠﺔ ﺍﻟﺘﺤﻤﻴﻞ ﺍﻟﺪﻳﻨﺎﻣﻴﻜﻰ ﻫﻰ ﺃﲪﺎﻝ ﺍﻷﺟـﺴﺎﻡ‬ ‫ﺍﳌﺘﺤﺮﻛﺔ ﻋﻨﺪ ﺻﺪﻣﻬﺎ ﺑﺄﺟﺴﺎﻡ ﺃﺧﺮﻯ ) ﻣﺜﻞ ﻫﺒﻮﻁ ﺍﻟﻄﺎﺋﺮﺓ ﻋﻠﻰ ﺃﺭﺽ ﺍﳌﻄﺎﺭ(‪ ،‬ﻭﺍﻷﲪﺎﻝ ﺍﻟﻨﺎﺷﺌﺔ ﻋـﻦ‬ ‫ﺩﻭﺭﺍﻥ ﺍﳌﺎﻛﻴﻨﺎﺕ ﻭﺣﺮﻛﺔ ﺍﻟﻘﻄﺎﺭﺍﺕ‪ ،‬ﻭﺃﲪﺎﻝ ﺍﻟﺰﻻﺯﻝ… ﻭﻏﲑﻫﺎ‪.‬‬ ‫‪@ @‰ŠØn½a@ÝîàznÛa MS‬‬ ‫ﺍﻟﺘﺤﻤﻴﻞ ﺍﳌﺘﻜﺮﺭ ﻫﻮ ﺍﳊﺎﻟﺔ ﺍﻟﱴ ﺗﺘﻌﺮﺽ ﻓﻴﻬﺎ ﺍﻟﻌﻨﺎﺻﺮ ﺍﻹﻧﺸﺎﺋﻴﺔ ﺇﱃ ﲪﻞ ﻳﺘﻜـﺮﺭ ﻣـﺮﺍﺕ ﻋﺪﻳـﺪﺓ‪.‬‬ ‫ﻭﻟﻠﺘﺤﻤﻴﻞ ﺍﳌﺘﻜﺮﺭ ﺃﳘﻴﺔ ﺧﺎﺻﻪ ﳚﺐ ﺍﻹﻫﺘﻤﺎﻡ ‪‬ﺎ ﻷﻥ ﺍﻟﻌﻨﺎﺻﺮ ﻗﺪ ﺗﺘﺤﻤﻞ ﺇﺟﻬـﺎﺩﺍﺕ ﻣﻌﻴﻨـﺔ ﺑﺘـﺄﺛﲑ‬ ‫ﺍﻷﲪﺎﻝ ﳌﺮﺓ ﻭﺍﺣﺪﺓ‪ ،‬ﺑﻴﻨﻤﺎ ﻗﺪ ﺗﻨﻬﺎﺭ ﻫﺬﻩ ﺍﻟﻌﻨﺎﺻﺮ ﲢﺖ ﺗﺄﺛﲑ ﻧﻔﺲ ﺍﻷﲪﺎﻝ ﺃﻭ ﺃﲪﺎﻝ ﺃﻗﻞ ﻣﻨﻬﺎ ﻟﻮ ﻛﺎﻥ‬ ‫ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻣﺘﻜﺮﺭﹰﺍ ﳌﺮﺍﺕ ﻋﺪﻳﺪﺓ‪ .‬ﻭﻳﺴﺒﺐ ﺍﻟﺘﺤﻤﻴﻞ ﺍﳌﺘﻜﺮﺭ ﺍﺟﻬﺎﺩﺍﺕ ﻣﺘﻐﲑﺓ ﰱ ﺍﻟﻘﻴﻤـﺔ ﻏﺎﻟﺒـﺎ ﰱ‬ ‫ﺣﺪﻭﺩ ﻣﻌﻴﻨﺔ‪ ،‬ﻭﳝﻜﻦ ﺗﻮﺿﻴﺢ ﺑﻌﺾ ﺣﺎﻻﺕ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﳌﺘﻜﺮﺭﺓ ﻓﻴﻤﺎ ﻳﻠﻲ‪:‬‬

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L‫ د‬JL‫د‬K‫ م‬J‫دم‬L‫د‬K‫אصאאدوא א‬

@ @NHRMQI@ÝØ‘@óÏ@bà×@NÁÌšÛa@óÏ@ôì–Ó@òàîÓ@µg@†’Ûa@óÏ@ôì–Ó@òàîÓ@åß@ñÌnß@pa…bèua MQ

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‫ﺍﻟﺰﻣﻦ‬

‫ﺿﻐﻂ‬ @ @ÁÌšÛa@óÏ@ôì–Ó@òàîÓ@µg@†’Ûa@óÏ@ôì–Ó@òàîÓ@í@ñÌnß@ñ‰ë…@HRMQIÝØ‘ NHSMQI@ÝØ‘@óÏbà×@caŠÐ•@ôëbm@òàîÓ@µg@ÁÌšÛa@ëc@†’Ûa@óÏ@ôì–Ó@òàîÓ@åß@ñÌnß@pa…bèua MR @@

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@@ @@ ‫ﺍﻟﺰﻣﻦ‬

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‫ﺿﻐﻂ‬ @ @ŠÐ–Ûa@µg@ôì–Ó@òàîÓ@í@ñÌnß@ñ‰ë…@HSMQIÝØ‘ @å;ØÛë@ÁÌš;Ûa@ëc@†’Ûa@óÏ@ôŠÌ•@òàîÓ@µg@ÁÌšÛa@ëc@†’Ûa@óÏ@óàÄÇ@òàîÓ@åß@ñÌnß@pa…bèua@ MS @HTMQI@ÝØ’Ûbi@|™ìß@ìç@bà×@ŠÐ–Ûa@åß@óÜÇc@òàîÔi @@ @@ ‫ﺷﺪ‬ @@ @@ @@ ‫ﺍﻟﺰﻣﻦ‬ @@ ‫ﺿﻐﻂ‬ @ @ôŠÌ•@òàîÓë@óàÄÇ@òàîÓ@í@ñÌnß@ñ‰ë…@HTMQIÝØ‘

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‫ﻭﻣﻦ ﻫﻨﺎ ﻳﺘﻀﺢ ﻟﻨﺎ ﺃﳘﻴﺔ ﺗﺄﺛﲑ ﺍﻷﲪﺎﻝ ﻋﻠﻰ ﺍﻟﻌﻨﺎﺻﺮ ﺍﻹﻧﺸﺎﺋﻴﺔ ﻭﻛﺬﻟﻚ ﺍﻟﻄﺮﻳﻘﺔ ﺍﻟﱴ ﻳﻨﺘﻘﻞ ‪‬ﺎ ﺍﳊﻤـﻞ‬ ‫ﻋﻠﻴﻬﻤﺎ ﳌﺎ ﳍﺎ ﻣﻦ ﺗﺄﺛﲑ ﻛﺒﲑ ﻋﻠﻰ ﺗﻌﻴﲔ ﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﺍﳌﺴﺘﺨﺪﻣﺔ ﻭﻣﻘﺎﻭﻣﺘﻬﺎ ﳍﺬﻩ ﺍﻷﲪﺎﻝ‪ .‬ﻟﺬﻟﻚ ﳚﺐ‬ ‫ﺃﻥ ﻧﻌﺘﲎ ﺑﺪﺍﺭﺳﺔ ﺗﺄﺛﲑ ﺍﻷﲪﺎﻝ ﺑﻜﻞ ﺟﺪﻳﺔ ﳌﺎ ﳍﺎ ﻣﻦ ﺃﳘﻴﺔ ﻛـﱪﻯ ﰱ ﺃﻋﻤـﺎﻝ ﺍﻟﺘـﺼﻤﻴﻢ ﻭﺣـﺴﺎﺏ‬ ‫ﺍﻟﻘﻄﺎﻋﺎﺕ ﺍﳌﻨﺎﺳﺒﺔ ﻟﻠﻌﻨﺎﺻﺮ ﺍﻹﻧﺸﺎﺋﻴﺔ ﺍﶈﻤﻠﺔ ﻭﻛﺬﻟﻚ ﺗﻌﻴﲔ ﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﺍﳌﻄﻠﻮﺑـﺔ ﻣـﻦ‬ ‫ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﱴ ﻳﺘﻢ ﺍﺧﺘﻴﺎﺭﻫﺎ ﻟﺬﻟﻚ‪.‬‬ ‫‪01( +,+ $ 8-1‬‬

‫ﻗﺪ ﰎ ﺗﻌﺮﻳﻒ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻠﻤﻮﺍﺩ ﺑﺄ‪‬ﺎ ﺗﻌﻴﲔ ﺳﻠﻮﻙ ﺍﳌﺎﺩﺓ ﲢﺖ ﺗﺄﺛﲑ ﺍﻷﲪﺎﻝ ﺍﳌﺨﺘﻠﻔﺔ‪ ،‬ﻭﺗﻌﺘـﱪ‬ ‫ﺍﳋﻮﺍﺹ ﺍﳌﻤﻴﺰﺓ ﺍﻵﺗﻴﺔ ﻫﻰ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﺍﻟﺮﺋﻴﺴﻴﺔ ﺍﻟﱴ ﳝﻜﻦ ‪‬ﺎ ﲤﻴﻴﺰ ﻭﺗﺼﻨﻴﻒ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ‪:‬‬ ‫‪@òãëŠ½a@M١‬‬

‫‪Elasticity‬‬

‫ﺍﳌﺮﻭﻧﺔ ﻫﻰ ﻗﺪﺭﺓ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﺍﺳﺘﻌﺎﺩﺓ ﺃﺑﻌﺎﺩﻫﺎ ﺍﻷﺻﻠﻴﺔ ﺑﻌﺪ ﺯﻭﺍﻝ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻭﻋﺪﻡ ﺑﻘﺎﺀ ﺃﻯ ﺗـﺸﻜﻞ‬ ‫ﺩﺍﺋﻢ ‪‬ﺎ‪ .‬ﺃﻣﺎ ﺑﺎﻟﻨﺴﺒﺔ ﻹﺟﻬﺎﺩ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﻓﺄﻧﻪ ﺃﻛﱪ ﺇﺟﻬﺎﺩ ﺗﺘﺤﻤﻠﺔ ﺍﳌﺎﺩﺓ ﺑﺸﺮﻁ ﻋﺪﻡ ﺑﻘﺎﺀ ﺃﻯ ﺗﻐـﲑ ﺃﻭ‬ ‫ﺗﺸﻜﻞ ﺩﺍﺋﻢ ﰱ ﺍﻷﺑﻌﺎﺩ ﻭﺍﻟﺸﻜﻞ ﺑﻌﺪ ﺯﻭﺍﻝ ﻫﺬﺍ ﺍﻹﺟﻬﺎﺩ‪.‬‬ ‫‪òãë†ÜÛa@M٢‬‬

‫‪Plasticity‬‬

‫ﺍﻟﻠﺪﻭﻧﺔ ﻫﻰ ﻗﺪﺭﺓ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﺃﻥ ﻳﻜﻮﻥ ﳍﺎ ﺗﺸﻜﻞ ﺩﺍﺋﻢ ﻭﻻ ﺗﺴﺘﺮﺟﻊ ﺍﳌﺎﺩﺓ ﺃﺑﻌﺎﺩﻫﺎ ﺍﻷﺻﻠﻴﺔ ﺑﻌﺪ ﺯﻭﺍﻝ‬ ‫ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ‪ .‬ﻭﳋﺎﺻﻴﺔ ﺍﻟﻠﺪﻭﻧﺔ ﺃﳘﻴﺔ ﻛﱪﻯ ﰱ ﻋﻤﻠﻴﺎﺕ ﺍﻟﺘﺸﻜﻴﻞ ﻟﻠﻤﻌﺎﺩﻥ‪.‬‬ ‫‪òîÛìĐà½a@M٣‬‬

‫‪Ductility‬‬

‫ﺍﳌﻤﻄﻮﻟﻴﺔ ﻫﻰ ﻗﺪﺭﺓ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﺍﻟﺴﺤﺐ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﻟﻜﺒﲑﺓ ﻋﻨﺪ ﺗﻌﺮﺿﻬﺎ ﻷﲪﺎﻝ ﺍﻟﺸﺪ ﺃﻯ ﺃ‪‬ﺎ ﻫـﻰ‬ ‫ﺍﳋﺎﺻﻴﻪ ﺍﻟﱴ ﺗﺴﻤﺢ ﻟﻠﻤﺎﺩﺓ ﺑﺘﻐﲑ ﻟﺪﻥ ﻛﺒﲑ ﲢﺖ ﺗﺄﺛﲑ ﺃﲪﺎﻝ ﺍﻟﺸﺪ‬ ‫ﻭﺗﻘﺎﺱ ﻗﻴﻤﺔ ﳑﻄﻮﻟﻴﺔ ﺍﳌﻮﺍﺩ ﲟﺎ ﻳﺄﺗﻰ‪:‬‬

‫‪ -١‬‬

‫‪*Ductility = Li - Lo × 100‬‬ ‫‪Lo‬‬

‫‪ -٢‬‬ ‫‪ -٣‬‬

‫‪× 100‬‬ ‫‪١٢‬‬

‫‪*Ductility = Ao - Ai× 100‬‬ ‫‪Ao‬‬

‫‪Ao - Ai‬‬ ‫‪Ai‬‬

‫= ‪*Elongation Factor‬‬


‫ﺣﻴﺚ‪:‬‬ ‫ﺍﻟﻄﻮﻝ ﺍﻷﺻﻠﻰ ﻟﻠﻌﻴﻨﺔ‬

‫= ‪L0‬‬

‫ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﻷﺻﻠﻴﺔ‬

‫= ‪A0‬‬

‫ﺍﻟﻄﻮﻝ ﺍﻟﻘﻴﺎﺳﻰ ﺑﻌﺪ ﺍﻟﻜﺴﺮ‬

‫= ‪Li‬‬

‫ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺑﻌﺪ ﺍﻟﻜﺴﺮ‬

‫= ‪Ai‬‬

‫ﲪﻞ ﺍﻟﺸﺪ‬

‫=‪P‬‬

‫‪Malleability òîÓëŠĐÛa@M٤‬‬

‫ﺍﻟﻄﺮﻭﻗﻴﺔ ﻫﻰ ﻗﺪﺭﺓ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﺣﺪﻭﺙ ﺗﻐﲑﺍﺕ ﻟﺪﻧﻪ ﻛﺒﲑﺓ ﲢﺖ ﺗﺄﺛﲑ ﺃﲪﺎﻝ ﺍﻟﻀﻐﻂ‪ ،‬ﻭﻛﺬﻟﻚ ﻗـﺪﺭ‪‬ﺎ‬ ‫ﻋﻠﻰ ﺍﻟﺘﻔﻠﻄﺢ ﺑﺎﻟﻄﺮﻕ ﺑﺪﻭﻥ ﺣﺪﻭﺙ ﺃﻯ ﺗﺸﺮﺥ ﺃﻭ ﻛﺴﺮ‬ ‫‪@ @Brittleness@ @@Ñ–ÔnÛa@M٥‬‬ ‫ﺍﻟﺘﻘﺼﻒ ﻫﻰ ﺍﳋﺎﺻﻴﺔ ﺍﻟﱴ ﲡﻌﻞ ﺍﳌﺎﺩﺓ ﺗﻨﻜﺴﺮ ﻗﺒﻞ ﺣﺪﻭﺙ ﺃﻯ ﺗﻐﲑ ﻣﻠﺤﻮﻅ ﰱ ﺍﻟﺸﻜﻞ ﺍﻭ ﺃ‪‬ﺎ ﻋـﺪﻡ‬ ‫ﻗﺎﺑﻠﻴﺔ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺃﻭ ﺍﻟﺴﺤﺐ ﺃﻭ ﺍﻟﻄﺮﻕ‪ ،‬ﻭﺑﺬﻟﻚ ﻓﺈﻥ ﺍﻟﺘﻘﺼﻒ ﻳﻌﺘﱪ ﻋﻜﺲ ﺍﳌﻤﻄﻮﻟﻴﺔ‪ .‬ﻭﻣﻦ‬ ‫ﺍﳌﻮﺍﺩ ﺍﻟﱴ ﳍﺎ ﺧﺎﺻﻴﺔ ﺍﻟﻘﺼﺎﻓﺔ ﻫﻰ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ ﻭﺍﳋﺮﺳﺎﻧﺔ ﻭﺍﻟﺰﺟﺎﺝ ﻭﻏﲑﻫﺎ‪.‬‬ ‫‪@òßëbÔ½a@M٦‬‬

‫‪Strength‬‬

‫ﺍﳌﻘﺎﻭﻣﺔ ﺗﻌﺮﻑ ﺑﺎ‪‬ﺎ ﻫﻰ ﻣﻘﺎﻭﻣﺔ ﺍﳌﺎﺩﺓ ﻷﻯ ﲪﻞ ﻣﺆﺛﺮ ﻋﻠﻴﻬﺎ ﺳﻮﺍﺀ ﻛﺎﻥ ﲪﻞ ﺷﺪ ﺃﻭ ﺿﻐﻂ ﺃﻭ ﺍﳓﻨﺎﺀ ﺍﻭ‬ ‫ﻗﺺ‪ ،‬ﻭﺗﻌﺮﻑ ﺑﺎﳌﻘﺎﻭﻣﺔ ﻟﻠﻀﻐﻂ ﺇﺫﺍ ﻛﺎﻥ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﲪﻞ ﺿﻐﻂ‪ ،‬ﻭﺍﳌﻘﺎﻭﻣﺔ ﻟﻠﺸﺪ ﺇﺫﺍ ﻛـﺎﻥ ﺍﳊﻤـﻞ‬ ‫ﺍﳌﺆﺛﺮ ﲪﻞ ﺷﺪ ﻭﻫﻜﺬﺍ‪ .‬ﻭﺃﻗﺼﻰ ﻣﻘﺎﻭﻣﺔ ﺗﻌﺮﻑ ﺑﺄ‪‬ﺎ ﺃﻛﱪ ﺇﺟﻬﺎﺩ ﺗﺘﺤﻤﻠﻪ ﺍﳌﺎﺩﺓ ﲢﺖ ﺗﺄﺛﲑ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ‬ ‫ﺑﺒﻂﺀ ﺣﱴ ﺍﻟﻜﺴﺮ‪ .‬ﻭﻭﺣﺪﺍﺕ ﻗﻴﺎﺱ ﺍﳌﻘﺎﻭﻣﺔ ﻫﻰ ﻧﻔﺴﻬﺎ ﻭﺣﺪﺍﺕ ﻗﻴﺎﺱ ﺍﻹﺟﻬﺎﺩ‪ ).‬ﻭﺣﺪﺍﺕ ﻗﻮﺓ ﻋﻠـﻰ‬ ‫ﻣﺴﺎﺣﺔ(‬ ‫‪òiý–Ûa@M٧‬‬

‫‪Stiffness‬‬

‫ﺍﻟﺼﻼﺑﺔ ﻫﻰ ﻣﻘﺎﻭﻣﺔ ﺍﳌﺎﺩﺓ ﻷﻯ ﻧﻮﻉ ﻣﻦ ﺍﻟﺘﻐﲑ ﰱ ﺍﻟﺸﻜﻞ ﻭﺍﻷﺑﻌﺎﺩ‪ ،‬ﻭﺗﻌﺮﻑ ﺍﳌﺎﺩﺓ ﺍﻟﺼﻠﺒﺔ ﺑﺄ‪‬ﺎ ﺍﳌـﺎﺩﺓ‬ ‫ﺍﻟﱴ ﺗﺘﺤﻤﻞ ﺇﺟﻬﺎﺩﺍﺕ ﻋﺎﻟﻴﺔ ﻣﻊ ﺣﺪﻭﺙ ﺗﻐﲑﺍﺕ ﺻﻐﲑﺓ ﻧﺴﺒﻴﺎ ﰱ ﺍﻟﺸﻜﻞ‪ .‬ﻭﺗﻘﺎﺱ ﻗﻴﻤـﺔ ﺍﻟـﺼﻼﺑﺔ‬ ‫ﻟﻠﻤﻮﺍﺩ ﲟﻘﺪﺍﺭ ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﺃﻭ ﻣﻌﺎﻳﺮ ﻳﻮﻧﺞ ﻟﻠﻤﺮﻭﻧﺔ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻭﺍﻟﻀﻐﻂ ﺍﶈﻮﺭﻯ ﻭﻫـﻮ ﻣﻘﻴـﺎﺱ‬ ‫ﺍﻟﺼﻼﺑﺔ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ‪ .‬ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﻫﻮ ﻗﻴﻤﺔ ﺍﻟﺰﻳﺎﺩﺓ ﰱ ﺍﻹﺟﻬﺎﺩ ﻣﻘﺴﻮﻣﺔ ﻋﻠﻰ ﺍﻟﺰﻳﺎﺩﺓ ﰱ ﺍﻻﻧﻔﻌﺎﻝ‬ ‫ﺍﳌﻘﺎﺑﻞ ﻟﻪ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﻟﻠﻤﺎﺩﺓ‬ ‫‪= (Modulus of Elasticity)@òãëŠ½a@ŠíbÈß‬‬ ‫‪١٣‬‬

‫اد )‪(σ‬‬ ‫ا ل )‪(ε‬‬


‫‪òãbn½a@M٨‬‬

‫‪Toughness‬‬

‫ﺍﳌﺘﺎﻧﺔ ﻫﻰ ﻗﺪﺭﺓ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻸﲪﺎﻝ ﺍﻟﺪﻳﻨﺎﻣﻴﻜﻴﺔ ﺃ ﺃ‪‬ﺎ ﺗﻌﱪ ﻋﻦ ﻗﺪﺭ‪‬ﺎ ﻋﻠﻰ ﻣﻘﺎﻭﻣـﺔ ﺃﲪـﺎﻝ‬ ‫ﺍﻟﺼﺪﻡ ﻭﺇﻣﺘﺼﺎﺹ ﺍﻟﻄﺎﻗﺔ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ‪ .‬ﻣﻊ ﺗﻐﲑ ﻛﺒﲑ ﰱ ﺍﻟﺸﻜﻞ ﺑﺪﻭﻥ ﺣﺪﻭﺙ ﻛﺴﺮ‪ .‬ﻭﺗﻘﺎﺱ ﺍﳌﺘﺎﻧـﺔ‬ ‫ﲟﻘﺪﺍﺭ ﺑﻘﻴﻤﺔ ﺍﳌﺴﺎﺣﺔ ﺍﻟﻜﻠﻴﺔ ﲢﺖ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﰱ ﺷﻜﻞ )‪ .(٩-١‬ﻭﻳﻌﺮﻑ ﻣﻌﺎﻳﺮ ﺍﳌﺘﺎﻧـﺔ‬ ‫ﲟﻘﺪﺍﺭ ﺍﻟﻄﺎﻗﺔ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻹﻧﻔﻌﺎﻝ ﻟﻠﻤﻮﺍﺩ ) ﺍﳌﺴﺎﺣﺔ ﺍﻟﻜﻠﻴﺔ ﲢﺖ ﻣﻨﺤﲎ ﺍﻹﺟﻬـﺎﺩ‬ ‫ﻭﺍﻻﻧﻔﻌﺎﻝ(‬ ‫‪Resilience òîÇìuŠÛa@M٩‬‬

‫ﺍﻟﺮﺟﻮﻋﻴﺔ ﻫﻰ ﻗﺪﺭﺓ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﺍﻣﺘﺼﺎﺹ ﺍﻟﻄﺎﻗﺔ ﺍﳌﺮﻧﺔ ﺍﻟﱴ ﲣﺘﻔﻰ ﺑﻌﺪ ﺯﻭﺍﻝ ﺍﳊﻤﻞ ﺍﳌـﺆﺛﺮ‪ .‬ﻭﺗﻘـﺎﺱ‬ ‫ﺍﻟﺮﺟﻮﻋﻴﺔ ﲟﻘﺪﺍﺭ ﺍﳌﺴﺎﺣﺔ ﲢﺖ ﺍﳉﺰﺀ ﺍﳌﺴﺘﻘﻴﻢ ﳌﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ(‪ .‬ﻭﻣﻌﺎﻳﺮ ﺍﻟﺮﺟﻮﻋﻴﺔ ﻳﻌـﺮﻑ‬ ‫ﺑﺄﻧﻪ ﺃﻛﱪ ﻛﻤﻴﺔ ﻣﻦ ﺍﻟﻄﺎﻗﺔ ﺍﳌﻴﻜﺎﻧﻴﻜﺔ ﺍﳌﺮﻧﺔ ﺍﻟﱴ ﲣﺘﺰ‪‬ﺎ ﻭﺣﺪﺓ ﺍﳊﺠﻮﻡ ﻣﻦ ﺍﳌﺎﺩﺓ ﻭﺗﺴﺘﺮﺟﻊ ﺛﺎﻧﻴﺔ ﲟﺠﺮﺩ‬ ‫ﺇﺯﺍﻟﺔ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ‪ .‬ﻭﻳﻌﻴﲔ ﻣﻘﺪﺍﺭ ﻣﻌﺎﻳﺮ ﺍﻟﺮﺟﻮﻋﻴﺔ ﻟﻠﻤﺎﺩﺓ ﲝﺴﺎﺏ ﺍﳌﺴﺎﺣﺔ ﺍﻟﱴ ﲢﺖ ﻣﻨﺤﲎ ﺍﻹﺟﻬـﺎﺩ‬ ‫ﻭﺍﻹﻧﻔﻌﺎﻝ ﺍﶈﺼﻮﺭﺓ ﺑﲔ ﺍﻟﺼﻔﺮ ﻭﺇﺟﻬﺎﺩ ﺣﺪ ﺍﳌﺮﻭﻧﺔ‬ ‫‪ñ…ý–Ûa@M١٠‬‬

‫‪Hardness‬‬

‫ﺍﻟﺼﻼﺩﺓ ﻫﻰ ﻗﺪﺭﺓ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﺍﻻﺣﺘﻔﺎﻅ ﺑﺸﻜﻞ ﺳﻄﺤﻬﺎ ﺳﻠﻴﻤﺎ ﻣﺘﻤﺎﺳﻜﺎ ﲢﺖ ﺗﺄﺛﲑ ﺍﻷﲪﺎﻝ ﺍﳌﺨﺘﻠﻔﺔ‪.‬‬ ‫ﻭﻗﺪ ﺗﻌﺮﻑ ﺍﻟﺼﻼﺩﺓ ﺑﺄ‪‬ﺎ ﻗﺪﺭﺓ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﻣﻘﺎﻭﻣﺔ ﺍﻟﱪﻯ ﻧﺘﻴﺠﺔ ﺍﻻﺣﺘﻜﺎﻙ ﺃﻭ ﺍﳌﻘﺎﻭﻣـﺔ ﻟﻠﺨـﺪﺵ ﺃﻭ‬ ‫ﺍﻟﻘﻄﻊ ﺃﻭ ﺣﺪﻭﺙ ﺃﻯ ﻋﻼﻣﺔ ‪‬ﺎ‪ .‬ﻭﻫﺬﺍ ﺍﻟﺘﻌﺮﻳﻒ ﻻ ﳝﻜﻦ ﺃﻥ ﻳﻜﻮﻥ ﺗﻌﺮﻳﻔﹰﺎ ﻋﺎﻣﹰﺎ ﻷﻥ ﺑﻌﺾ ﺍﳌﻌﺎﺩﻥ ﳍـﺎ‬ ‫ﻣﻘﺎﻭﻣﺔ ﺿﻌﻴﻔﺔ ﻟﻨﻮﻉ ﻣﻦ ﺃﻧﻮﺍﻉ ﺍﻟﺼﻼﺩﺓ ﺑﻴﻨﻤﺎ ﳍﺎ ﻗﺪﺭﺓ ﻋﺎﻟﻴﺔ ﰱ ﻧﻮﻉ ﺃﺧﺮ‪،‬‬ ‫‪Endurance Þbànyüa@M١١‬‬

‫ﺍﻻﺣﺘﻤﺎﻝ ﻫﻰ ﻗﺪﺭﺓ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﻣﻘﺎﻭﻣﺔ ﺍﻷﲪﺎﻝ ﺍﳌﺆﺛﺮﺓ ﺍﳌﺘﻜﺮﺭﺓ ﻣﺮﺍﺕ ﻋﺪﻳﺪﺓ‪ .‬ﻭﻳﻌﺮﻑ ﺣﺪ ﺍﻻﺣﺘﻤﺎﻝ‬ ‫ﺑﺄﻧﻪ ﺃﻛﱪ ﺇﺟﻬﺎﺩ ﻣﺘﻜﺮﺭ ﳝﻜﻦ ﺗﻌﺮﻳﺾ ﺍﳌﺎﺩﺓ ﻟﻪ ﻋﺪﺩﹰﺍ ﻻ‪‬ﺎﺋﻴﺎ ﻣﻦ ﺍﳌﺮﺍﺕ ﺩﻭﻥ ﺃﻥ ﻳﺴﺒﺐ ﺍ‪‬ﻴﺎﺭ ﻟﻠﻤﺎﺩﺓ‪.‬‬

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‫‪ 3 4 5 678 9":"( 9 -1‬‬ ‫‪Inspection & Quality control‬‬

‫ﻳﻌﺘﱪ ﺍﻟﺘﻔﺘﻴﺶ ﻭﺿﺒﻂ ﺍﳉﻮﺩﺓ ﻣﻦ ﺃﻫﻢ ﺍﳌﺆﺛﺮﺍﺕ ﻋﻠﻰ ﻛﻔﺎﺀﺓ ﺗﻨﻔﻴﺬ ﺍﻷﻋﻤـﺎﻝ ﺍﳍﻨﺪﺳـﻴﺔ‪ ،‬ﻭﻳﺘـﻀﻤﻦ‬ ‫ﺍﻟﺘﻔﺘﻴﺶ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﻣﻼﺣﻈﺎﺕ ﻋﻤﻠﻴﺎﺕ ﺍﻟﺼﻨﺎﻋﺔ ﻭﻧﺘﺒﻊ ﺧﻄﻮﺍﺕ ﺍﻹﻧﺘﺎﺝ ﺃﻭ ﺧﻄﻮﺍﺕ ﺍﻹﻧﺸﺎﺀ ﻟﻠﺘﺄﻛﺪ‬ ‫ﻣﻦ ﺗﻮﺍﺟﺪ ﺍﳋﻮﺍﺹ ﺍﳌﻄﻠﻮﺑﺔ ﻟﻠﻤﻮﺍﺩ ﻭﺍﳌﻨﺸﺂﺕ‪ .‬ﻭﻗﺪ ﻳﺘﻢ ﺍﻟﺘﻔﺘﻴﺶ ﻋﻠﻰ ﺍﳌـﻮﺍﺩ ﺑـﺎﻟﻔﺤﺺ ﺍﻟﺒـﺼﺮﻯ‬ ‫ﻭﺑﺎﻟﻜﺸﻒ ﻋﻦ ﺍﻟﻌﻴﻮﺏ ﺍﻟﺴﻄﺤﻴﺔ ﻭﺑﺈﺟﺮﺍﺀ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﳌﻌﻤﻠﻴﺔ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﻭﺍﳌﻨﺸﺂﺕ ﻭﺫﻟﻚ ﻟﻠﺘﺄﻛـﺪ‬ ‫ﻣﻦ ﻣﻄﺎﺑﻘﺔ ﺍﳌﻮﺍﺩ ﻟﻼﺷﺘﺮﺍﻃﺎﺕ ﺍﳌﻄﻠﻮﺑﺔ‪ .‬ﻭﻳﻬﺪﻑ ﺍﻟﺘﻔﺘﻴﺶ ﺇﱃ ﺍﻟﺘﺤﻜﻢ ﰱ ﺟﻮﺩﺓ ﺍﳌـﻮﺍﺩ ﺃﻭ ﺍﳌﻨـﺸﺂﺕ‬ ‫ﻭﺭﻓﺾ ﻣﺎ ﻳﻈﻬﺮ ﻣﻨﻬﺎ ﺃﻗﻞ ﻣﻦ ﺍﳌﺴﺘﻮﻯ ﺍﳌﻄﻠﻮﺏ‪ .‬ﻭﺍﻟﺘﻔﺘﻴﺶ ﺍﻟﻔﲎ ﻣﺎ ﻫﻮ ﺇﻻ ﺗﻄﺒﻴﻖ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻔﻨﻴـﺔ‬ ‫ﺍﳌﻄﻠﻮﺑﺔ ﻋﻠﻰ ﳐﺘﻠﻒ ﻣﺮﺍﺣﻞ ﺍﻷﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ ﻭﺍﻟﺘﺄﻛﺪ ﻣﻦ ﻣﻄﺎﺑﻘﺔ ﻫﺬﻩ ﺍﻷﻋﻤﺎﻝ ﻟﻸﺻـﻮﻝ‬ ‫ﺍﻟﻔﻨﻴﺔ‪ ،‬ﻭﻳﻘﻮﻡ ﺑﺎﻟﺘﻔﺘﻴﺶ ﺍﻟﻔﲎ ﺃﻯ ﻣﻦ ﺍﳍﻴﺌﺎﺕ ﺍﳌﺴﺌﻮﻟﺔ ﻋﻦ ﺿﺒﻂ ﺍﳉﻮﺩﺓ ﻭﺍﻟﱴ ﳍـﺎ ﺍﳋـﱪﺓ ﺍﻟﺘﺎﻣـﺔ‬ ‫ﻭﺍﻟﺪﺭﺍﻳﺔ ﺍﻟﻔﻨﻴﺔ ﺍﻟﻌﺎﻟﻴﺔ‪ .‬ﻭ ﺍﳍﻴﺌﺎﺕ ﺍﻟﻔﻨﻴﺔ ﻟﻠﺘﻔﺘﻴﺶ ﻫﻰ ﻫﻴﺌﺎﺕ ﺣﻜﻮﻣﻴﺔ ﺃﻭ ﻫﻴﺌﺎﺕ ﺃﻫﻠﻴﺔ ﺃﻭ ﳎﻤﻮﻋﺔ ﻣﻦ‬ ‫ﺍﳌﻬﻨﺪﺳﲔ ﺍﳌﺘﺨﺼﺼﲔ‪ .‬ﻭﻳﺸﺘﺮﻁ ﻓﻴﻤﻦ ﻳﻘﻮﻡ ﺑﺎﻟﺘﻔﺘﻴﺶ ﺍﻹﳌﺎﻡ ﺍﻟﻌﻠﻤﻰ ﺍﻟﺘﺎﻡ ﻟﻠﻌﻤﻠﻴـﺔ ﺍﻟـﱴ ﻳﺮﺍﺟﻌﻬـﺎ‬ ‫ﻭﻛﺬﻟﻚ ﻳﻜﻮﻥ ﻋﻠﻰ ﺩﺭﺍﻳﺔ ﲝﺴﻦ ﺍﳌﻌﺎﻣﻼﺕ ﻣﻊ ﺍﳍﻴﺌﺎﺕ ﺍﻟﱴ ﻳﺘﺎﺑﻌﻬﺎ ﻭﻳﻜﻮﻥ ﻋﻠﻰ ﻣﻌﺮﻓﺔ ﺗﺎﻣﺔ ﺑﻜﻴﻔﻴـﺔ‬ ‫ﺇﺟﺮﺍﺀ ﺍﻟﻔﺤﻮﺹ ﻭﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﳌﻄﻠﻮﺑﺔ‪.‬‬ ‫‪Specifications <:= 10-1‬‬

‫ﻣﻮﺍﺻﻔﺎﺕ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻫﻰ ﺍﻻﺷﺘﺮﺍﻃﺎﺕ ﺍﻟﱴ ﻳﺘﻢ ﻭﺿﻌﻬﺎ ﻟﻠﻤﻨﺘﺠﲔ ﺃﻭ ﺍﳌﻨﻔﺬﻳﻦ ﻣﻦ ﻗﺒﻞ ﺻـﺎﺣﺐ‬ ‫ﺍﻟﻌﻤﻠﻴﺔ ﺍﳍﻨﺪﺳﻴﺔ ﻭﺍﻟﱴ ﲢﻘﻖ ﺍﻟﺮﻏﺒﺎﺕ ﻭﺍﳋﻮﺍﺹ ﺍﳌﻄﻠﻮﺑﺔ ﰱ ﺍﻟﻌﻤﻠﻴـﺔ ﺍﳍﻨﺪﺳـﻴﺔ‪ .‬ﻭﺗﺘﻮﻗـﻒ ﻛﻔـﺎﺀﺓ‬ ‫ﺍﳌﻨﺘﺠﺎﺕ ﻭﺣﺴﻦ ﺗﻨﻔﻴﺬ ﺍﻟﻌﻤﻠﻴﺎﺕ ﻋﻠﻰ ﺩﻗﺔ ﻭﺳﻼﻣﺔ ﺍﻻﺷﺘﺮﺍﻃﺎﺕ ﺍﶈﺪﺩﺓ ﳍﺎ‪ .‬ﻭﻧﻈﺮﹰﺍ ﻟﻠﺘﻘﺪﻡ ﺍﻟﻌﻠﻤـﻰ‬ ‫ﺍﳌﺴﺘﻤﺮ ﻭﻛﺬﻟﻚ ﺍﳌﻌﺮﻓﺔ ﺍﳌﺘﻄﻮﺭﺓ ﻋﻦ ﺍﳌﻮﺍﺩ ﻭﺧﻮﺍﺻﻬﺎ ﻭﺍﻟﺘﻄﻮﺭ ﺍﻟـﺼﻨﺎﻋﻰ ﻭﺍﻻﻧـﺸﺎﺋﻰ ﻟﻠﻌﻤﻠﻴـﺎﺕ‬ ‫ﺍﳍﻨﺪﺳﻴﺔ ﻓﺈﻧﻪ ﳝﻜﻨﻨﺎ ﻭﺿﻊ ﺍﺷﺘﺮﺍﻃﺎﺕ ﺃﻛﺜﺮ ﺗﻌﺒﲑﹰﺍ ﻭﺃﺩﻕ ﲢﺪﻳﺪﹰﺍ ﳌﺎ ﳚﺐ ﺃﻥ ﺗﻜﻮﻥ ﻋﻠﻴـﻪ ﺍﳌﻨﺘﺠـﺎﺕ‬ ‫ﻭﺍﳌﻨﺸﺂﺕ ﺍﳌﻄﻠﻮﺑﺔ‪ .‬ﻣﻊ ﺍﻟﺘﻘﺪﻡ ﻭﺍﻟﺘﻄﻮﺭ ﻭﺍﳌﻌﺮﻓﺔ ﺑﺄﻧﻪ ﳚﺐ ﺃﻥ ﻧﻘﻮﻡ ﺑﻌﻤﻞ ﻣﻮﺍﺻﻔﺎﺕ ﻣﻨﺎﺳـﺒﺔ ﺃﻛﺜـﺮ‬ ‫ﻓﺎﻋﻠﻴﺔ ﻟﺘﺘﻤﺎﺷﻰ ﻣﻊ ﻫﺬﺍ ﺍﻟﺘﻘﺪﻡ‪ .‬ﻭﺗﺼﻒ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﳌﺜﺎﻟﻴﺔ ﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﺍﻟﻼﺯﻣﺔ ﻷﺩﺍﺀ ﻋﻤﻞ ﻫﻨﺪﺳﻰ‬ ‫ﻣﻌﲔ ﺑﻜﻔﺎﺀﺓ ﻋﺎﻟﻴﺔ‪ .‬ﻭﻗﺪ ﺗﻜﻮﻥ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺃﻗﻞ ﻣﻦ ﺍﳌﺴﺘﻮﻯ ﺍﳌﺜﺎﱃ ﺍﳌﻄﻠﻮﺏ ﻟﻌﺪﺓ ﺃﺳﺒﺎﺏ ﻣﻨﻬﺎ‪:‬‬

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‫ ﺃﻥ ﺗﻜﻮﻥ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺫﺍﺕ ﺷﺮﻭﻁ ﺳﻬﻠﺔ ﺗﺴﺎﻋﺪ ﻋﻠﻰ ﺍﺳﺘﺨﺪﺍﻡ ﻣﻮﺍﺩ ﺫﺍﺕ ﺧﻮﺍﺹ ﻏﲑ ﺟﻴﺪﺓ ﰱ‬‫ﺍﻻﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ ﳑﺎ ﳚﻌﻠﻬﺎ ﺗﺆﺛﺮ ﺑﺸﻜﻞ ﻣﺒﺎﺷﺮ ﻋﻠﻰ ﻛﻔﺎﺀﺓ ﻫﺬﻩ ﺍﻷﻋﻤﺎﻝ‪.‬‬ ‫ ﺃﻥ ﺗﻜﻮﻥ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺫﺍﺕ ﺷﺮﻭﻁ ﻣﺘﺸﺪﺩﺓ ﻓﺘﻤﻨﻊ ﺍﳌﻮﺍﺩ ﺫﺍﺕ ﺍﳉـﻮﺩﺓ ﺍﳌﻨﺎﺳـﺒﺔ ﺍﻟﻌﺎﻟﻴـﺔ ﻣـﻦ‬‫ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﰱ ﺍﻷﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﻨﺎﺳﺒﺔ‪.‬‬ ‫ ﺃﻥ ﺗﻜﻮﻥ ﺍﳌﻮﺍﺻﻔﺎﺕ ﻣﻌﺪﺓ ﻋﻠﻰ ﻣﻌﻠﻮﻣﺎﺕ ﺧﺎﻃﺌﺔ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻨﻮﻉ ﺍﻟﻌﻤﻞ ﺍﳌﻄﻠﻮﺏ ﻣﺘﺴﺒﺐ ﺍﻷﺧﻄﺎﺀ‬‫ﺍﻟﻔﻨﻴﺔ ﰱ ﺍﻷﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ‪.‬‬ ‫ﻛﻤﺎ ﳚﺐ ﻣﺮﺍﻋﺎﺓ ﺃﻥ ﺍﳌﻮﺍﺻﻔﺎﺕ ﻻ ﺗﻌﺪ ﻟﻠﻤﻮﺍﺩ ﺍﳌﺜﺎﻟﻴﺔ ﻓﻘﻂ ﻭﻟﻜﻦ ﺗﻌﺪ ﻟﻜﻰ ﺗﺴﻤﺢ ﺑﺎﺳﺘﺨﺪﺍﻡ ﻛﺎﻓـﺔ‬ ‫ﺍﳌﻮﺍﺩ ﺍﳌﻤﻜﻦ ﺍﳊﺼﻮﻝ ﻋﻠﻴﻬﺎ ﺑﺘﻜﺎﻟﻴﻒ ﻣﻨﺎﺳﺒﺔ ﲢﺖ ﺍﻟﻈﺮﻭﻑ ﺍﶈﻴﻄﺔ ﺑﺎﻷﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﻄﻠﻮﺑﺔ‪.‬‬ ‫ﻭﲢﺘﻮﻯ ﺍﳌﻮﺍﺻﻔﺎﺕ ﻋﻠﻰ ﺍﺷﺘﺮﺍﻃﺎﺕ ﳐﺘﻠﻔﺔ ﺗﺘﻌﻠﻖ ﺑﺎﻟﻨﻮﺍﺣﻰ ﺍﻟﺘﺎﻟﻴﺔ‪:‬‬ ‫‪ -١‬ﻃﺮﻕ ﺍﻟﺼﻨﺎﻋﺔ ﻭﺗﻜﻨﻮﻟﻮﺟﻴﺎ ﺍﻹﻧﺘﺎﺝ‪.‬‬ ‫‪ -٢‬ﺍﻟﺸﻜﻞ ﻭﺍﻷﺑﻌﺎﺩ ﻭﺍﻟﺘﺸﻄﻴﺐ‪.‬‬ ‫‪ -٣‬ﺍﳋﻮﺍﺹ ﺍﻟﻄﺒﻴﻌﻴﺔ ﻭﺍﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﻭﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻭﻏﲑﻫﺎ ﺍﳌﻄﻠﻮﺑﺔ‪.‬‬ ‫‪ -٤‬ﺣﺪﻭﺩ ﺍﻟﻌﻴﻮﺏ ﺍﻟﻐﲑ ﻣﺮﻏﻮﺏ ﻓﻴﻬﺎ‪.‬‬ ‫‪ -٥‬ﻛﻴﻔﻴﺔ ﲢﻀﲑ ﺍﻟﻌﻴﻨﺎﺕ ﻟﻼﺧﺘﺒﺎﺭ ﻭﺑﻄﺮﻕ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺍﻟﺘﻔﺘﻴﺶ‪.‬‬ ‫‪ -٦‬ﺍﻟﻘﺒﻮﻝ ﻭﺍﻟﺮﻓﺾ ﻭﺍﻟﺘﺤﻜﻢ‪.‬‬ ‫‪ <7" ١١- 1‬‬

‫ﻳﺮﺗﻜﺰ ﻋﻠﻢ ﺍﺧﺘﺒﺎﺭ ﺍﳌﻮﺍﺩ ﻋﻠﻰ ﺗﺼﻨﻴﻔﺎﺕ ﻛﺜﲑﺓ ﻭﻋﺪﻳﺪﺓ ﻟﻮﺿﻊ ﺍﻷﺳﺲ ﺍﻟـﱴ ﲢﻜـﻢ ﻋﻠـﻰ ﺟـﻮﺩﺓ‬ ‫ﻭﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﺍﳌﺴﺘﺨﺪﻣﺔ‪.‬‬ ‫ﻭﻋﻠﻴﻪ ﻓﺈﻧﻪ ﳝﻜﻦ ﺗﻘﺴﻴﻢ ﺃﻧﻮﺍﻉ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﺇﱃ ﻣﺎ ﻳﻠﻰ ‪:‬‬ ‫‪@ @ZïÜí@bàîÏ@bè–î‚Üm@åØ¹ë@‰bjnüa@õaŠug@åß@āŠÌÛa@óÜÇ@ÑÓìnm@pa‰bjna@Q@MQQMQ‬‬ ‫‪@ @òí‰bvnÛa@pa‰bjnüa@–@c‬‬ ‫ﺍﻻﺧﺘﺒﺎﺭ ﺍﻟﺘﺠﺎﺭﻱ ﳚﺮﻱ ﺑﻐﺮﺽ ﺍﻟﺘﺤﻜﻢ ﰲ ﺍﳌﻮﺍﺩ ﻭﺍﳌﻨﺘﺠﺎﺕ ﻟﻠﺤﺼﻮﻝ ﻋﻠﻰ ﺍﻟﺒﻴﺎﻧﺎﺕ ﺍﻟﺪﻭﺭﻳـﺔ ﻋـﻦ‬ ‫ﺧﻮﺍﺻﻬﺎ ﻭﻟﻠﺘﺄﻛﺪ ﻣﻦ ﻗﺒﻮﻝ ﺃﻭ ﺭﻓﺾ ﺍﳌﻮﺍﺩ ﻭﺍﳌﻨﺘﺠﺎﺕ ﻃﺒﻘﺎ ﻟﺸﺮﻭﻁ ﺍﻟﺸﺮﺍﺀ ﺃﻭ ﺣـﺪﻭﺩ ﺍﻟـﺼﻨﺎﻋﺔ ‪،‬‬ ‫ﻭﻫﺬﻩ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺑﺴﻴﻄﺔ ﻭﻻ ﻳﻠﺰﻡ ﳍﺎ ﺩﺭﺟﺔ ﻋﺎﻟﻴﺔ ﻣﻦ ﺍﻟﺪﻗﺔ ﻟﻠﻨﺘﺎﺋﺞ ‪ ،‬ﻭﺗﻌﻤﻞ ﺍﺧﺘﺒﺎﺭﺍﺕ ﻣﺘﻨﻮﻋﺔ ﳍـﺎ‬ ‫ﺳﻮﺍﺀ ﻃﺒﻴﻌﻴﺔ ﺃﻭ ﻛﻴﻤﻴﺎﺋﻴﺔ ﺃﻭ ﻣﻴﻜﺎﻧﻴﻜﻴﺔ ﺃﻭ ﻓﺤﺺ ﻣﻴﻜﺮﻭﺳﻜﻮﰊ ‪.‬‬ ‫‪١٦‬‬


‫‪@ @òîrzjÛa@pa‰bjnüa@–@l‬‬ ‫ﻭﲣﺘﺺ ﻫﺬﻩ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺑﺎﻟﻨﻮﺍﺣﻲ ﺍﻟﺒﺤﺜﻴﺔ ﻟﻠﺤﺼﻮﻝ ﻋﻠﻰ ﻣﻌﻠﻮﻣﺎﺕ ﺟﺪﻳﺪﺓ ﻋـﻦ ﻣـﻮﺍﺩ ﺟﺪﻳـﺪﺓ ‪،‬‬ ‫ﻭﻛﺬﻟﻚ ‪‬ﺘﻢ ﺑﺎﻛﺘﺸﺎﻑ ﺧﻮﺍﺹ ﺟﺪﻳﺪﺓ ﻟﻠﻤﻮﺍﺩ ‪ ،‬ﻭﺃﻳﻀﺎ ﲣﺘﺺ ﺑﺘﺤﺴﲔ ﻭﺗﻄﻮﻳﺮ ﺍﳋـﻮﺍﺹ ﺍﻟﻘﻴﺎﺳـﻴﺔ‬ ‫ﻟﻠﻤﻮﺍﺩ ﺍﳌﻌﺮﻭﻓﺔ ﺃﻭ ﺃﺳﻠﻮﺏ ﺇﺟﺮﺍﺀ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﻭﳛﺘﻤﻞ ﺃﻳﻀﺎ ﺃﻥ ﻳﻀﺎﻑ ﺇﱃ ﻫﺬﻩ ﺍﻷﻏﺮﺍﺽ ﻏﺮﺽ ﻣﻌﲔ‬ ‫ﻣﺜﻞ ﺍﺧﺘﺒﺎﺭ ﺍﳌﺎﺩﺓ ﻻﺳﺘﻌﻤﺎﻝ ﺧﺎﺹ‪ ،‬ﺃﻭ ﺗﻌﻴﲔ ﺍﻷﺳﺲ ﺍﻟﻔﻌﺎﻟﺔ ﻟﺘﺤﺴﲔ ﺍﻟﺘـﺼﻤﻴﻢ ﻭﺩﺭﺍﺳـﺔ ﺳـﻠﻮﻙ‬ ‫ﺍﳌﻨﺸﺂﺕ ﺃﻭ ﺃﺣﺪ ﺍﻟﻌﻨﺎﺻﺮ ﺍﻹﻧﺸﺎﺋﻴﺔ ﻭﳍﺬﻩ ﺍﳌﻨﺸﺂﺕ ﲢﺖ ﻇﺮﻭﻑ ﺍﻟﺘﺸﻐﻴﻞ ﺍﳌﺨﺘﻠﻔﺔ ﻭﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣـﻦ‬ ‫ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﻳﺘﻄﻠﺐ ﻣﻨﻔﺬﻳﻦ ﻭﻓﻨﻴﲔ ﻭﺑﺎﺣﺜﲔ ﻣﻬﺮﺓ ﺫﻭ ﺧﱪﺓ ﻋﺎﻟﻴﺔ‪.‬‬ ‫‪@ @@òîàÜÈÛa@pa‰bjnüa@M;u‬‬ ‫ﺍﻻﺧﺘﺒﺎﺭ ﺍﻟﻌﻠﻤﻲ ﳚﺮﻯ ﺑﻐﺮﺽ ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﻣﻘﺎﻳﻴﺲ ﺩﻗﻴﻘﺔ ﻟﻠﺨﻮﺍﺹ ﺍﻷﺳﺎﺳﻴﺔ ﺃﻭ ﺍﻟﺜﻮﺍﺑﺖ ﺍﻟﻄﺒﻴﻌﻴـﺔ‬ ‫ﻋﻦ ﻃﺮﻳﻖ ﲡﻤﻴﻊ ﺑﻴﺎﻧﺎﺕ ﻋﺪﻳﺪﺓ ﺑﻐﺮﺽ ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﺑﻴﺎﻧﺎﺕ ﻟﻠﺘﺤﻠﻴﻞ ﺍﻟـﺪﻗﻴﻖ ﺑـﺴﻠﻮﻙ ﺍﳌﻨـﺸﺂﺕ‬ ‫ﻭﺍﻟﺘﺼﻤﻴﻢ ﺍﻟﻔﻌﺎﻝ ﳍﺎ‪ ،‬ﻭﻳﺘﻄﻠﺐ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﺪﻗﺔ ﺍﻟﻌﺎﻟﻴﺔ ﻭﺍﻟﻌﻨﺎﻳﺔ ﺍﻟﻔﺎﺋﻘﺔ‪.‬‬ ‫‪@ @ÝàÈÛa@ÉÓì¶@ôŠ£@pa‰bjna@@R@MQQMQ‬‬ ‫ﻫﺬﻩ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﲡﺮﻯ ﰱ ﻣﻮﻗﻊ ﺍﻟﻌﻤﻞ ﺑﺄﺟﻬﺰﺓ ﺑﺴﻴﻄﺔ ﻏﺎﻟﺒﺎ ﻣﺎ ﻳﻨﻘﺼﻬﺎ ﺍﻟﺪﻗﺔ ﺑﺎﻟﻨﺴﺒﺔ ﳌﺜﻴﻼ‪‬ـﺎ ﺍﻟـﱴ‬ ‫ﲡﺮﻯ ﺑﺎﳌﻌﻤﻞ ﻧﻈﺮﺍ ﻟﺼﻌﻮﺑﺔ ﻇﺮﻭﻑ ﺍﻟﺘﺸﻐﻴﻞ ﻭﺍﻷﺣﻮﺍﻝ ﺍﳉﻮﻳﺔ ﺍﳌﺘﻐﲑﺓ ﻭﲢﺪﻳﺪ ﻣﺪﺓ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺍﻷﺳﺒﺎﺏ‬ ‫ﺍﳌﺨﺘﻠﻔﺔ ﺍﻟﱴ ﻗﺪ ﺗﻌﺮﺽ ﺃﻭ ﺗﻘﻠﻞ ﻛﻔﺎﺀﺓ ﺇﺟﺮﺍﺀ ﺍﻻﺧﺘﺒﺎﺭ‪ .‬ﻭﻗﺪ ﻳﺘﻢ ﺇﺟﺮﺍﺀ ﺑﻌﺾ ﻣﻦ ﻫﺬﻩ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﰱ‬ ‫ﻣﻌﺎﻣﻞ ﺻﻐﲑﺓ ﲟﻮﻗﻊ ﺍﻟﻌﻤﻞ ﺃﻭ ﻣﻌﺎﻣﻞ ﻗﺮﻳﺒﺔ ﻣﻦ ﻣﻮﻗﻊ ﺍﻟﻌﻤﻞ ﳚﺮﻯ ﳍﺎ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﳌﻄﻠﻮﺑﺔ‪ ،‬ﻭﺗﻜـﻮﻥ‬ ‫ﻫﺬﻩ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﳌﻌﻤﻠﻴﺔ ﺃﻓﻀﻞ ﻭﺃﻛﺜﺮ ﺩﻗﺔ ﻋﻦ ﺍﻟﱵ ﲡﺮﻯ ﲟﻮﻗﻊ ﺍﻟﻌﻤﻞ‪.‬‬ ‫‪@ @ñn‚½a@pbäîÈÛa@ÊìänÛ@bÔj@ôŠ£@pa‰bjna@@S@MQQMQ‬‬ ‫ﲡﺮﻯ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﻣﻦ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﺇﻣﺎ ﻋﻠﻰ ﺍﳌﻨﺸﺄ ﻧﻔﺴﻪ ﺃﻭ ﻋﻠﻰ ﻋﻨﺎﺻﺮ ﻣﻦ ﻋﻨﺎﺻﺮﻩ ﺍﻹﻧﺸﺎﺋﻴﺔ ﺃﻯ ﻋﻠﻰ‬ ‫ﺟﺰﺀ ﻣﻨﻪ ﺃﻭ ﻋﻠﻰ ﻋﻴﻨﺎﺕ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﳌﺼﻨﻌﺔ ﺃﻭ ﺍﳌﻨﺘﺠﺎﺕ ﺃﻭ ﻋﻠﻰ ﻋﻴﻨﺎﺕ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﳋﺎﻡ ﺃﻭ ﻋﻠﻰ ﳕﺎﺫﺝ‬ ‫ﻟﻠﻤﻨﺸﺄ ﺃﻭ ﻋﻠﻰ ﺃﻯ ﺟﺰﺀ ﻣﻦ ﺃﺟﺰﺍﺋﻪ‪ .‬ﻭﻳﻼﺣﻆ ﺃﻧﻪ ﳝﻜﻦ ﺃﻥ ﲡﺮﻯ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﻋﻠﻰ ﳕـﺎﺫﺝ ﻣـﺼﻐﺮﺓ‬ ‫ﻟﻠﻌﻨﺼﺮ ﺍﻹﻧﺸﺎﺋﻲ ﺃﻭ ﻟﻠﻤﻨﺸﺄ ﺍﳍﻨﺪﺳﻲ ﺑﺎﻟﻜﺎﻣﻞ‪.‬‬

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‫‪@ @òÐÜn½a@Ëë@òÐÜn½a@pa‰bjnüa@@T@MQQMQ‬‬ ‫ﳝﻜﻦ ﺗﻘﺴﻴﻢ ﻫﺬﻩ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﻃﺒﻘﺎ ﻟﻠﺤﺎﻟﺔ ﺍﻟﻨﻬﺎﺋﻴﺔ ﻟﻌﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﺑﻌﺪ ﺍﻧﺘﻬﺎﺀ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﻋﻠﻴﻬﺎ ﺇﱃ‬ ‫ﺍﺧﺘﺒﺎﺭﺍﺕ ﻣﺘﻠﻔﺔ ﻭﺍﺧﺘﺒﺎﺭﺍﺕ ﻏﲑ ﻣﺘﻠﻔﺔ‪ .‬ﻓﻼﺧﺘﺒﺎﺭﺍﺕ ﺍﳌﺘﻠﻔﺔ ﺗﻈﻬﺮ ﰱ ﺣﺎﻟﺔ ﻣﺎ ﻳﻜﻮﻥ ﺍﳌﻄﻠـﻮﺏ ﺗﻌـﻴﲔ‬ ‫ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻷﻯ ﻣﺎﺩﺓ ﰱ ﺍﻟﺸﺪ ﺃﻭ ﺍﻟﻀﻐﻂ ﻣﺜﻼ ﻓﻬﺬﺍ ﻳﻌﲎ ﻛﺴﺮ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻣﻦ ﻫـﺬﻩ ﺍﳌـﺎﺩﺓ‬ ‫ﻭﺗﺼﺒﺢ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﻏﲑ ﺻﺎﳊﺔ ﻷﺩﺍﺀ ﻋﻤﻠﻬﺎ ﺑﺎﳌﻨﺸﺄ ﺃﻯ ﺃﺗﻠﻔﺖ ﺑﺈﺟﺮﺍﺀ ﺍﻻﺧﺘﺒﺎﺭ ﺃﻣﺎ ﻋﻨﺪ ﺍﺧﺘﺒﺎﺭﹰﺍ‬ ‫ﺍﳌﻨﺘﺠﺎﺕ ﺍﳌﻨﺘﻬﻴﺔ ﻓﻴﻠﺰﻡ ﻋﺪﻡ ﺇﺗﻼﻑ ﺃﻯ ﺟﺰﺀ ﻓﻴﻬﺎ ﻭﳛﺘﺎﺝ ﺫﻟﻚ ﺇﱃ ﺍﺧﺘﺒﺎﺭﺍﺕ ﻏﲑ ﻣﺘﻠﻔﺔ ﻣﺜﻞ ﺍﻻﺧﺘﺒﺎﺭ‬ ‫ﺑﺎﻷﺷﻌﺔ ﺃﻭ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﳌﻮﺟﺎﺕ ﻓﻮﻕ ﺍﻟﺼﻮﺗﻴﺔ ﻭﺍﺧﺘﺒﺎﺭﺍﺕ ﺻﻼﺩﺓ ﺍﻟﻌﻼﻣـﺔ ﻭﺍﻻﺧﺘﺒـﺎﺭﺍﺕ ﺍﻟـﻀﻮﺋﻴﺔ‬ ‫ﻭﺍﺧﺘﺒﺎﺭ ﻣﻄﺮﻗﺔ ﴰﻴﺪﺕ ﻋﻠﻰ ﺍﻟﻌﻨﺎﺻﺮ ﺍﳋﺮﺳﺎﻧﻴﺔ‪.‬‬ ‫‪ ( 7" # <> . , 12 -1‬‬

‫ﺍﺳﺘﺨﺪﺍﻡ ﺃﺟﻬﺰﺓ ﻭﻣﺎﻛﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﻟﻪ ﺃﳘﻴﺔ ﻛﱪﻯ ﰱ ﺇﲤﺎﻡ ﺍﻻﺧﺘﺒﺎﺭ ﻟﻠﻤﻮﺍﺩ ﺍﳍﻨﺪﺳـﻴﺔ ﻭﺍﳌﻨـﺸﺂﺕ‬ ‫ﻭﺑﺪﻭﻥ ﺍﻷﺟﻬﺰﺓ ﻻ ﻳﺘﻢ ﺇﺟﺮﺍﺀ ﺍﻻﺧﺘﺒﺎﺭ‪ ،‬ﻭﻣﺮﺕ ﺃﺟﻬﺰﺓ ﺍﻟﻘﻴﺎﺱ ﻭﺍﳌﺎﻛﻴﻨـﺎﺕ ﻷﻧـﻮﺍﻉ ﺍﻻﺧﺘﺒـﺎﺭﺍﺕ‬ ‫ﺍﳌﺨﺘﻠﻔﺔ ﺑﺘﻄﻮﺭﺍﺕ ﻋﺪﻳﺪﺓ ﰱ ﻣﺮﺍﺣﻞ ﺻﻨﺎﻋﺘﻬﺎ ﺣﱴ ﻭﺻﻠﻨﺎ ﺇﱃ ﺍﻟﺼﻮﺭﺓ ﺍﳊﺎﻟﻴﺔ ﻟﻸﺟﻬﺰﺓ ﻭﺍﳌﺎﻛﻴﻨـﺎﺕ‬ ‫ﺍﳊﺪﻳﺜﺔ‪ .‬ﳝﻜﻦ ﺗﻘﺴﻴﻢ ﻣﺎﻛﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﺇﱃ ﺍﻷﻧﻮﺍﻉ ﺍﻵﺗﻴﺔ‪:‬‬ ‫‪ " # $ %&' -1‬‬ ‫ﻣﺎﻛﻴﻨﺎﺕ ﺍﺧﺘﺒﺎﺭ ﻣﺼﻤﻤﺔ ﻹﺟﺮﺍﺀ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﻣﺜﻞ ﺍﻟﺸﺪ ﻭﺍﻟﻀﻐﻂ ﻭﺍﻻﳓﻨﺎﺀ‪ .‬ﺷﻜﻞ ‪.٥-١‬‬ ‫‪+,- ../ # $ %&' -2‬ء ‪) # $‬‬ ‫ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﳌﺎﻛﻴﻨﺎﺕ ﺃﺣﺎﺩﻯ ﺍﻻﺳﺘﺨﺪﺍﻡ ﺃﻱ ﲡﺮﻯ ﺍﺧﺘﺒﺎﺭ ﻭﺍﺣﺪ ﻓﻘﻂ ﻣﺜﻞ ﻣﺎﻛﻴﻨﺔ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﺃﻭ‬ ‫ﻣﺎﻛﻴﻨﺔ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ]ﺷﻜﻞ )‪ [(٦-١‬ﺃﻭ ﻣﺎﻛﻴﻨﺔ ﺍﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﺷﻜﻞ ‪.٧-١‬‬ ‫‪ 12 # $ %&' -3‬‬ ‫ﻫﻰ ﺍﳌﺎﻛﻴﻨﺎﺕ ﺍﳌﺼﻤﻤﺔ ﻹﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭﺍﺕ ﺧﺎﺻﺔ ﻣﺜﻞ ﺍﻟﺼﻼﺩﺓ ﺷﻜﻞ ‪ ٨-١‬ﺍﻭ ﺍﻻﻟﺘﻮﺍﺀ ﺷﻜﻞ ‪٩-١‬‬ ‫ﺍﻭ ﺍﻟﺼﺪﻡ ﺷﻜﻞ ‪ ١٠-١‬ﺃﻭ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻘﻠﺐ ﺍﳋﺮﺳﺎﱏ ﺷﻜﻞ ‪.١١-١‬‬ ‫‪ & 4+ # $ %&' -4‬‬ ‫ﻫﺬﻩ ﺍﳌﺎﻛﻴﻨﺎﺕ ﺭﺃﺳﻴﺔ ﻷﻥ ﺍﻟﺘﺄﺛﲑ ﺑﺎﳊﻤﻞ ﺭﺃﺳﻴﺎ ﻣﺜﻞ ﻣﺎﻛﻴﻨﺎﺕ ﺍﺧﺘﺒﺎﺭ ﺍﻷﻋﻤﺪﺓ‪.‬‬ ‫‪١٨‬‬


‫‪ & # $ %&' -5‬‬ ‫ﻳﺼﻤﻢ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﳌﺎﻛﻴﻨﺎﺕ ﲝﻴﺚ ﻳﺘﺤﺮﻙ ﻓﻴﻬﺎ ﺭﺃﺱ ﺍﻟﺘﺤﻤﻴﻞ ﰲ ﺍﻻﲡـﺎﻩ ﺍﻷﻓﻘـﻲ ﻭﻳﻔـﻀﻞ‬ ‫ﺍﺳﺘﺨﺪﺍﻣﻪ ﰱ ﺣﺎﻟﺔ ﺍﻟﻌﻴﻨﺎﺕ ﺍﻟﻄﻮﻳﻠﺔ ﻧﺴﺒﻴﺎ ﻛﻤﺎ ﻫﻰ ﺍﳊـﺎﻝ ﰱ ﺍﺧﺘﺒـﺎﺭﺍﺕ ﺍﻟـﺴﻼﺳﻞ ﺃﻭ ﺍﳊﺒـﺎﻝ‬ ‫ﻭﺍﻷﺳﻼﻙ ﺷﻜﻞ )‪ .(١٢-١‬ﺇﺫ ﺃﻥ ﻃﺒﻴﻌﻴﺔ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﲢﺘﻢ ﻃـﻮﻻ ﻣﻌﻴﻨـﺎ ﻟﻘﻄﻌـﺔ‬ ‫ﺍﻻﺧﺘﺒﺎﺭ ﻭﻗﺪ ﻻ ﻳﺴﻤﺢ ﺑﻪ ﺍﺭﺗﻔﺎﻉ ﺍﳌﻌﻤﻞ ﻟﻮ ﻛﺎﻥ ﲢﻤﻴﻞ ﺍﳌﺎﻛﻴﻨﺔ ﺭﺃﺳﻴﹰﺎ‪.‬‬ ‫‪ 9:; 4 & " <#+7 %,#8 ) # $ %&' -6‬‬ ‫ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﳌﺎﻛﻴﻨﺎﺕ ﺗﺴﺘﺨﺪﻡ ﻟﺪﺭﺍﺳﺔ ﺳﻠﻮﻙ ﺍﳌﻮﺍﺩ ﻋﻨﺪ ﺩﺭﺟﺎﺕ ﺍﳊﺮﺍﺭﺓ ﺍﳌﺨﺘﻠﻔﺔ ﻭﻣﻦ ﻫـﺬﻩ‬ ‫ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺰﺣﻒ ﻋﻨﺪ ﺩﺭﺟﺎﺕ ﺍﳊﺮﺍﺭﺓ ﺍﻟﻌﺎﻟﻴﺔ ﻭﺍﺧﺘﺒﺎﺭ ﺍﻟﺘﻤﺪﺩ ﻋﻨﺪ ﺩﺭﺟـﺎﺕ ﺍﳊـﺮﺍﺭﺓ‬ ‫ﺍﳌﺨﺘﻠﻔﺔ‪.‬‬ ‫‪>,4 4 ' %&' 4 %?@ # $ %&' -7‬ء ' ‪:%?@ 4 %&' ABC D‬‬ ‫ﻣﺜﻞ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻗﺎﻋﺪﺓ ﺍﻻﺧﺘﺒﺎﺭ ﺍﳌﺰﻭﺩﺓ ‪‬ﺎ ﻛﻞ ﺍﻟﺘﺤﻤﻴﻞ ﻭﺑﻀﻐﻮﻁ ﻫﻴﺪﺭﻭﻟﻴﻜﻴﺔ ﻟﻠﺘـﺄﺛﲑ ﺑﺎﳊﻤـﻞ‪.‬‬ ‫ﻭﻳﺘﻀﺢ ﻣﻦ ﺍﻟﺘﻘﺴﻴﻢ ﺍﻟﺴﺎﺑﻖ ﻷﻧﻮﺍﻉ ﻣﺎﻛﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﺃﻧﻪ ﺃﻫﻢ ﻫﺬﻩ ﺍﻷﻧﻮﺍﻉ ﻫﻮ ﻣﺎﻛﻴﻨﺎﺕ ﺍﻻﺧﺘﺒـﺎﺭ‬ ‫ﺍﻟﻌﺎﻣﺔ ﺣﻴﺚ ﳝﻜﻦ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﰱ ﺍﺧﺘﺒﺎﺭﺍﺕ ﻋﺪﻳﺪﺓ‪.‬‬

‫‘‪òßbÈÛa@‰bjnüa@òäî×bß@H@U@MQI@ÝØ‬‬

‫‪١٩‬‬


@ @ÁÌšÛa@‰bjna@òäî×bß@V@MQ@ÝØ‘

@ @õbä−üa@‰bjna@òäî×bß@H@W@M@QI@ÝØ‘

٢٠


@ @ñ…ý–Ûa@‰bjna@òäî×bß@H@X@MQI@ÝØ‘

@ @õaìnÛüa@òäî×bß@HY@–@QI@ÝØ‘

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@@ óãbŠä@kÜÔÛa@‰bjna@òäî×bß@HQQMQI@ÝØ‘

@ @â†–Ûa@‰bjna@òäî×bß@HQPMQI@ÝØ‘

ÝýÛa@†’Û@òîÔÏc@‰bjna@òäî×bß@HQRMQI@ÝØ‘

٢٢


‫‪@ @‰bjnüa@pbäî×bß@ñŠíbÈß‬‬ ‫ﳚﺐ ﻣﻌﺎﻳﺮﺓ ﻣﺎﻛﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﺍﳌﺨﺘﻠﻔﺔ ﺑﺄﻧﻮﺍﻋﻬﺎ ﻣﻦ ﻭﻗﺖ ﺇﱃ ﺁﺧﺮ ﻟﻠﺘﺄﻛﺪ ﻣﻦ ﺩﻗﺔ ﻗﻴـﺎﺱ ﻭﻗـﺮﺍﺀﺓ‬ ‫ﺍﻷﲪﺎﻝ ﻭﺃﻥ ﺍﻷﲪﺎﻝ ﺍﳌﻘﺮﻭﺀﺓ ﺑﺎﳌﺎﻛﻴﻨﺔ ﲤﺜﻞ ﺍﻟﻘﻴﻢ ﺍﳊﻘﻴﻘﻴﺔ ﻟﻸﲪﺎﻝ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﻋﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﻣـﻦ‬ ‫ﺑﺪﺍﻳﺔ ﺍﻟﺘﺤﻤﻴﻞ ﺣﱴ ﺃﻗﺼﻰ ﲪﻞ ﳌﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺃﻧﻪ ﻻ ﻳﻮﺟﺪ ﺃﻯ ﺧﻄﺄ ﰱ ﺍﳊﻤﻞ ﰱ ﺍﳌﺮﺍﺣﻞ ﳐﺘﻠﻔـﺔ‬ ‫ﻟﻠﺘﺤﻤﻴﻞ‪ .‬ﻭﻳﻠﺰﻡ ﻣﻌﺎﻳﺮﺓ ﻣﺎﻛﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﻟﻸﺳﺒﺎﺏ ﺍﻵﺗﻴﺔ‪:‬‬ ‫ ﻳﺘﻢ ﻣﻌﺎﻳﺮﺓ ﺍﳌﺎﻛﻴﻨﺔ ﺑﻌﺪ ﺍﻻﻧﺘﻬﺎﺀ ﻣﻦ ﺗﺼﻨﻴﻌﻬﺎ ﻣﺒﺎﺷﺮﺓ ﻭﺗﺴﻤﻰ ﲟﻌﺎﻳﺮﺓ ﺍﳌﺼﻨﻊ‪.‬‬‫ ﲡﺮﻯ ﺍﳌﻌﺎﻳﺮﺓ ﻋﻠﻰ ﻓﺘﺮﺍﺕ ﺩﻭﺭﻳﺔ ﻻ ﺗﺰﻳﺪ ﻋﻦ ﺳﻨﺘﲔ ﻭﻫﺬﻩ ﻣﻌﺎﻳﺮﺓ ﰱ ﺍﳌﻌﻤﻞ‪.‬‬‫ ﺗﺄﺛﺮ ﺍﳌﺎﻛﻴﻨﺎﺕ ﻋﻨﺪ ﻧﻘﻠﻬﺎ ﻣﻦ ﻣﻜﺎﻥ ﻵﺧﺮ‪.‬‬‫ ﺑﻌﺪ ﺣﺪﻭﺙ ﺃﻯ ﺃﻋﻄﺎﻝ ﺑﺎﳌﺎﻛﻴﻨﺔ ﻭﺑﻌﺪ ﺍﻹﺻﻼﺡ ﻳﺘﻢ ﻣﻌﺎﻳﺮﺓ ﺍﳌﺎﻛﻴﻨﺔ ﻟﻠﺘﺄﻛﺪ ﻣﻦ ﺩﻗﺘﻬﺎ‪.‬‬‫ﺃﺛﻨﺎﺀ ﻣﻌﺎﻳﺮﺓ ﺍﳌﺎﻛﻴﻨﺔ ﻳﺘﻢ ﺍﻟﺘﺄﺛﲑ ﺑﺎﳊﻤﻞ ﻋﻠﻰ ﺟﻬﺎﺯ ﺍﳌﻌﺎﻳﺮﺓ ﻭﺫﻟﻚ ﺍﺑﺘﺪﺍﺀﹰﺍ ﻣﻦ ﺻﻔﺮ ﺍﻟﺘﺤﻤﻴﻞ ﻭﻳـﺰﺩﺍﺩ‬ ‫ﺗﺪﺭﳚﻴﺎ ﺣﱴ ﺍﻟﻮﺻﻮﻝ ﺇﱃ ﺃﻗﺼﻰ ﲪﻞ ﻟﻠﻤﺎﻛﻴﻨﺔ ﰒ ﻳﺘﻢ ﺗﺪﻭﻳﻦ ﻗﺮﺍﺀﺓ ﺍﳌﺎﻛﻴﻨﺔ ﻋﻨﺪ ﺍﻷﲪﺎﻝ ﺍﳌﺨﺘﻠﻔﺔ ﺍﳌﻌﻴﻨﺔ‬ ‫ﻭﺗﺪﻭﻳﻦ ﺃﻳﻀﺎ ﺍﻟﻘﺮﺍﺀﺓ ﺍﳌﻘﺎﺑﻠﺔ ﻟﻜﻞ ﲪﻞ ﺟﻬﺎﺯ ﺍﳌﻌﺎﻳﺮﺓ ﻭﻫﻰ ﺍﻟﻘﻴﻢ ﺍﳊﻘﻴﻘﻴﺔ ﻟﻸﲪﺎﻝ‪ ،‬ﻭﻣﻦ ﻫﺬﻩ ﺍﻟﻘـﻴﻢ‬ ‫ﻟﻸﲪﺎﻝ ﻳﺘﻢ ﺣﺴﺎﺏ ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻠﺨﻄﺄ ﺑﲔ ﻗﺮﺍﺀﺓ ﺍﳌﺎﻛﻴﻨﺔ ﻭﻗﺮﺍﺀﺓ ﺟﻬﺎﺯ ﺍﳌﻌﺎﻳﺮﺓ ﻭﻫﻮ ﺍﳊﻤﻞ ﺍﳊﻘﻴﻘﻲ‬ ‫ﻭﺗﻜﻮﻥ ﻗﻴﻤﺔ ﺍﳋﻄﺄ ﺳﺎﻟﺒﺔ ﺃﻭ ﻣﻮﺟﺒﺔ ﺣﺴﺐ ﺇﺷﺎﺭﺓ ﺍﻟﻔﺮﻕ ﻭﺫﻟﻚ ﻣﻦ ﺍﻟﻌﻼﻗﺔ ﺍﻟﺘﺎﻟﻴﺔ‪-:‬‬ ‫ﺍﳋﻄﺄ ‪= %‬‬

‫ﻗﺮﺍﺀﺓ ﺍﳌﺎﻛﻴﻨﺔ – ﻗﺮﺍﺀﺓ ﺟﻬﺎﺯ ﺍﳌﻌﺎﻳﺮﺓ‬ ‫ﻗﺮﺍﺀﺓ ﺟﻬﺎﺯ ﺍﳌﻌﺎﻳﺮﺓ‬

‫ﻭﺑﻌﺪ ﺍﺣﺘﺴﺎﺏ ﻛﻞ ﺍﻟﻨﺴﺐ ﺍﳌﻄﻠﻮﺑﺔ ﳉﻤﻴﻊ ﺍﻷﲪﺎﻝ ﻳﺘﻢ ﺭﺳﻢ ﻣﻨﺤﲎ ﺍﳌﻌﺎﻳﺮﺓ ﺑﲔ ﺍﳊﻤﻞ ﺍﳊﻘﻴﻘﻲ )ﲪﻞ‬ ‫ﺟﻬﺎﺯ ﺍﳌﻌﺎﻳﺮﺓ( ﻭﻧﺴﺒﺔ ﺍﳋﻄﺄ‪ ) %‬ﻣﻮﺟﺒﺔ ﺃﻭ ﺳﺎﻟﺒﺔ(‪ ،‬ﻭﻟﻠﺤﻜﻢ ﻋﻠﻰ ﺩﻗﺔ ﺍﳌﺎﻛﻴﻨﺔ ﳚﺐ ﺃﻻ ﺗﺰﻳﺪ ﻧـﺴﺒﺔ‬ ‫ﺍﳋﻄﺄ ﻋﻦ ‪ ،%١ ±‬ﻭﺇﺫﺍ ﺍﳓﺮﻓﺖ ﺍﻟﻘﻴﻢ ﻋﻦ ﻫﺬﻩ ﺍﳊﺪﻭﺩ ﻓﺘﺤﺘﺎﺝ ﺍﳌﺎﻛﻴﻨﺔ ﺇﱃ ﺿﺒﻂ‪.‬‬

‫‪٢٣‬‬


‫‪?':,# @A 13 -1‬‬

‫ﻣﻘﺎﻳﻴﺲ ﺍﻻﻧﻔﻌﺎﻝ ﻫﻰ ﺍﻷﺟﻬﺰﺓ ﺍﻟﱴ ﺗﺴﺘﺨﺪﻡ ﰱ ﻗﻴﺎﺱ ﺍﻟﺘﺸﻜﻞ ﺍﻟﻄﻮﱃ ﻭﺫﻟﻚ ﻟﻄﻮﻝ ﻣﻌﲔ ﺃﺛﻨﺎﺀ ﲢﻤﻴﻞ‬ ‫ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻭﺍﻟﱴ ﻣﻨﻪ ﳝﻜﻦ ﺗﻌﻴﻴﲔ ﺍﻻﻧﻔﻌﺎﻝ ﻟﻠﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻛﻤﺎ ﻳﻠﻰ‪:‬‬ ‫ﺍﻻﻧﻔﻌﺎﻝ =‬

‫ﺍﻟﺘﺸﻜﻞ ﺍﻟﻄﻮﱃ ﺍﳊﺎﺩﺙ‬

‫)‪(∆L‬‬

‫ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﺍﻷﺻﻠﻰ ﻟﻠﻌﻴﻨﺔ )‪(L‬‬

‫ﻭﻳﻜﻮﻥ ﺍﻻﻧﻔﻌﺎﻝ ﺑﺎﻟﺸﺪ ﺃﻭ ﺑﺎﻟﻀﻐﻂ ﺗﺒﻌﺎ ﳊﺎﻟﺔ ﺍﻟﺘﺸﻜﻞ ﰱ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﺇﺫﺍ ﻛﺎﻥ ﺑﺎﻟﺰﻳـﺎﺩﺓ ﻳﻜـﻮﻥ ﰱ‬ ‫ﺍﻟﺸﺪ ﻭﺇﺫﺍ ﻛﺎﻥ ﺑﺎﻟﻨﻘﺼﺎﻥ ﻳﻜﻮﻥ ﰱ ﺍﻟﻀﻐﻂ ﻭﺗﻮﺟﺪ ﺃﻧﻮﺍﻉ ﻣﺘﻌﺪﺩﺓ ﻣﻦ ﻣﻘﺎﻳﻴﺲ ﺍﻻﻧﻔﻌﺎﻝ ﻣﻨﻬﺎ‪:‬‬ ‫ ﺍﳌﻘﺎﻳﻴﺲ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ‬

‫‬

‫ﺍﳌﻘﺎﻳﻴﺲ ﺍﻟﻀﻮﺋﻴﺔ‬

‫ ﺍﳌﻘﺎﻳﻴﺲ ﺍﻟﻜﻬﺮﺑﻴﺔ‬

‫‪@ @ÞbÈÐãýÛ@òîØîãbØî½a@îíbÔ½a@Q@M@QSM@Q‬‬ ‫@@‬ ‫ﺗﺘﻠﺨﺺ ﻧﻈﺮﻳﺔ ﻋﻤﻞ ﺗﻠﻚ ﺍﻷﺟﻬﺰﺓ ﰲ ﺃ‪‬ﺎ ﺗﻘﻮﻡ ﺑﺘﻜﺒﲑ ﺍﻟﺘﺸﻜﻞ ﺍﳊﺎﺩﺙ ﻣﻴﻜﺎﻧﻴﻜﻴﺎ ﻋﻦ ﻃﺮﻳﻖ ﳎﻤﻮﻋﺔ‬ ‫ﻣﻦ ﺍﻷﻧﻮﺍﻉ ﻭﺍﻟﺘﺮﻭﺱ ﻭﺣﻴﺚ ﺃﻧﻪ ﻳﻼﺣﻆ ﺃﻥ ﺍﻟﺘﺸﻜﻞ ﺍﻟﻄﻮﱄ ﰱ ﺍﳌﻨﺸﺂﺕ ﻭﻋﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﺻﻐﲑ ﺟﺪﹰﺍ‬ ‫ﻭﺧﺼﻮﺻﺎ ﰲ ﻣﺮﺣﻠﺔ ﺍﳌﺮﻭﻧﺔ ﻭﻻ ﳝﻜﻦ ﻗﻴﺎﺳﻪ ﺑﺎﻷﺟﻬﺰﺓ ﺍﳌﻌﺘﺎﺩﺓ ﻭﻻﺑﺪ ﻣﻦ ﺗﻜﺒﲑﻩ ﺣﱴ ﳝﻜﻦ ﲢﺪﻳـﺪﻩ‪.‬‬ ‫‪@ @ZòîØîãbØî½a@ÞbÈÐãüa@îíbÔß@paŒî¾@åßë‬‬ ‫•‬ ‫•‬ ‫•‬ ‫•‬ ‫•‬ ‫•‬

‫ﺗﺴﺘﺨﺪﻡ ﰱ ﻧﻄﺎﻕ ﻭﺍﺳﻊ ﰱ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﳌﺨﺘﻠﻔﺔ ﻭﺗﻌﺘﱪ ﺃﻛﺜﺮ ﻣﻨﺎﺳﺒﺔ ﰱ ﺑﻌﺾ ﺍﳊﺎﻻﺕ‪.‬‬ ‫ﳍﺬﻩ ﺍﻷﺟﻬﺰﺓ ﺍﻛﺘﻔﺎﺀ ﺫﺍﺗﻰ ﻻ ﲢﺘﺎﺝ ﺇﱃ ﻣﺴﺎﻋﺪﺓ ﺃﻯ ﺃﺟﻬﺰﺓ ﺁﺧﺮﻯ‪.‬‬ ‫ﳝﻜﻦ ﻗﺮﺍﺀﺓ ﺍﻟﻨﺘﺎﺋﺞ ﺑﺴﻬﻮﻟﺔ ﻭﻭﺿﻮﺡ ﻋﻠﻰ ﻣﻘﻴﺎﺱ ﺃﻭ ﻗﺮﺹ ﻣﺪﺭﺝ‪.‬‬ ‫ﻫﺬﻩ ﺍﻷﺟﻬﺰﺓ ﻣﺘﻴﻨﺔ ﻭﺗﻌﺘﱪ ﺭﺧﻴﺼﺔ ﻭﺳﻬﻠﺔ ﺍﻻﺳﺘﺨﺪﺍﻡ ﻭﻣﻌﻤﺮﺓ ﻟﻔﺘﺮﺍﺕ ﻃﻮﻳﻠﺔ‪.‬‬ ‫ﻳﺴﻬﻞ ﺍﺳﺘﺨﺪﺍﻡ ﻫﺬﻩ ﺍﻷﺟﻬﺰﺓ ﻋﻠﻰ ﻋﻴﻨﺎﺕ ﳍﺎ ﺃﻛﺜﺮ ﻣﻦ ﻃﻮﻝ ﻗﻴﺎﺱ‪.‬‬ ‫ﳝﻜﻦ ﻣﻌﺎﻳﺮﺓ ﻫﺬﻩ ﺍﻷﺟﻬﺰﺓ ﺑﺴﻬﻮﻟﺔ‪.‬‬

‫‪@ @ZòîØîãbØî½a@ÞbÈÐãüa@îíbÔß@lìîÇ@åßë‬‬ ‫• ﺃﻥ ﻣﻘﺪﺍﺭ ﺍﻟﺘﻜﺒﲑ ﺍﳊﺎﺩﺙ ﻟﻠﺘﺸﻜﻞ ﳏﺪﻭﺩ ﻭﻻ ﻳﺰﻳﺪ ﻋﻦ ‪٢٠٠٠‬ﻣﺮﺓ‬ ‫• ﺃﻥ ﻫﺬﻩ ﺍﳌﻘﺎﻳﻴﺲ ﻻ ﺗﺼﻠﺢ ﻟﻘﻴﺎﺱ ﺍﻟﺘﺸﻜﻞ ﺍﻟﻨﺎﺗﺞ ﻣﻦ ﺍﳊﻤﻞ ﺍﻟـﺪﻳﻨﺎﻣﻴﻜﻰ ﻗﺒـﻞ ﺍﻟـﺼﺪﻡ ﺃﻭ‬ ‫ﺍﻻﻫﺘﺰﺍﺯﺍﺕ‬ ‫• ﻫﺬﻩ ﺍﻷﺟﻬﺰﺓ ﻳﻨﻘﺼﻬﺎ ﺍﻟﺪﻗﺔ ﺃﺣﻴﺎﻧﺎ ﻧﺘﻴﺠﺔ ﻋﻮﺍﻣﻞ ﻻ ﳝﻜﻦ ﺗﻼﻓﻴﻬﺎ ﻭﻫﻰ ﺍﻟـﻮﺯﻥ ﻭﺍﻻﺣﺘﻜـﺎﻙ‬ ‫ﻭﻣﺪﻯ ﻗﺎﺑﻠﻴﺔ ﺃﺟﺰﺍﺋﻬﺎ ﻟﻼﻧﺜﻨﺎﺀ ﻭﻋﺪﻡ ﻓﺎﻋﻠﻴﺔ ﺍﳊﺮﻛﺔ‪.‬‬ ‫‪٢٤‬‬


‫ﻭﻣﻦ ﺃﻫﻢ ﻫﺬﻩ ﺍﻷﻧﻮﺍﻉ ﻭﺃﺷﻬﺮﻫﺎ ﺍﺳﺘﺨﺪﺍﻣﺎ ﻫﻮ ﻧﻮﻉ ﺍﳌﻘﺎﻳﻴﺲ ﺫﺍﺕ ﺍﻟﺘﺮﺱ ﻭﺍﻟﻘﺮﺹ ﺍﳌﺪﺭﺝ ﻛﻤﺎ ﻫـﻮ‬ ‫ﻣﺒﲔ ﺑﺎﻟﺸﻜﻞ‪.١٣-١‬‬

‫‘‪@ @x‰†½a@˜ŠÔÛaë@÷Ûa@pa‡@÷bîÔ½a@HQSMQI@ÝØ‬‬ ‫@@‬

‫‪@ @ÞbÈÐãfiÛ@òîöìšÛa@îíbÔ½a@R@M@QSM@Q‬‬ ‫ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﳌﻘﺎﻳﻴﺲ ﻳﺘﻜﻮﻥ ﻣﻦ ﺃﺫﺭﻉ ﻣﻴﻜﺎﻧﻴﻜﻴﺔ ﻭﻣﺮﺍﻳﺎ ﻭﻋﺪﺳﺎﺕ ﺿﻮﺋﻴﺔ ﺣﻴﺚ ﻳﺜﺒـﺖ ﺍﻟـﺴﻄﺢ‬ ‫ﺍﻟﻌﺎﻛﺲ ﻟﻠﻀﻮﺀ ﻭﻫﻮ ﺍﳌﺮﺁﺓ ﻣﺮﺗﻜﺰﺍ ﻋﻠﻰ ﺫﺭﺍﻉ ﻣﺮﻛﺐ ﻋﻠﻰ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻟﻠﺠﺴﻢ ﺍﳌﺨﺘﱪ‪ ،‬ﻓﺈﺫﺍ ﺣﺪﺙ‬ ‫ﺗﺸﻜﻞ ﰱ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻓﺈﻥ ﺫﻟﻚ ﻳﺘﺴﺒﺐ ﰱ ﺩﻭﺭﺍﻥ ﺍﻟﺴﻄﺢ ﺍﻟﻌﺎﻛﺲ ﻟﻠﻀﻮﺀ‪ .‬ﻭﺇﺫﺍ ﺃﺭﺳـﻠﺖ ﺃﺷـﻌﺔ‬ ‫ﺿﻮﺋﻴﺔ ﻟﺘﺴﻘﻂ ﻋﻠﻰ ﺳﻄﺢ ﺍﻟﻌﺎﻛﺲ ﻭﺗﺮﺗﺪ ﻋﻠﻰ ﻣﻘﻴﺎﺱ ﻣﺪﺭﺝ ﺑﺎﳉﻬﺎﺯ ﻓﺈﻥ ﻣﻘﺪﺭﺍ ﺣﺮﻛﺔ ﺍﻷﺷﻌﺔ ﻧﺘﻴﺠﺔ‬ ‫ﺩﻭﺭﺍﻥ ﺍﻟﺴﻄﺢ ﺍﻟﻌﺎﻛﺲ ﺍﻟﱴ ﻳﺒﻴﻨﻬﺎ ﺍﳌﻘﻴﺎﺱ ﺍﳌﺪﺭﺝ ﺗﻌﱪ ﻋﻦ ﺍﻟﺘﺸﻜﻞ ﰱ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﺃﻯ ﲤﺜﻞ ﻗﻴﻤـﺔ‬ ‫ﺫﻟﻚ ﺍﻟﺘﺸﻜﻞ ﻣﻜﱪﹰﺍ‬ ‫‪@ @ÞbÈÐãfiÛ@òîiŠèØÛa@îíbÔ½a@@S@M@QSM@Q‬‬ ‫ﺗﻘﺴﻢ ﺍﳌﻘﺎﻳﻴﺲ ﺍﻟﻜﻬﺮﺑﻴﺔ ﻟﻺﻧﻔﻌﺎﻝ ﺇﱃ ﺛﻼﺙ ﺃﻧﻮﺍﻉ‬ ‫ ﻣﻘﺎﻳﻴﺲ ﺍﻻﻧﻔﻌﺎﻝ ﺑﺎﶈﺎﺛﺔ ﺍﻟﻜﻬﺮﺑﻴﺔ‪.‬‬‫ ﻣﻘﺎﻳﻴﺲ ﺍﻻﻧﻔﻌﺎﻝ ﺑﺎﻟﺴﻌﺔ ﺍﻟﻜﻬﺮﺑﻴﺔ‪.‬‬‫ ﻣﻘﺎﻳﻴﺲ ﺍﻻﻧﻔﻌﺎﻝ ﺑﺎﳌﻘﺎﻭﻣﺔ ﺍﻟﻜﻬﺮﺑﻴﺔ‪.‬‬‫‪٢٥‬‬


‫ﻭﻣﻦ ﺍﻟﺘﻄﺒﻴﻘﺎﺕ ﻭﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﳌﻌﻤﻠﻴﺔ ﻟﻘﻴﺎﺱ ﺍﻧﻔﻌﺎﻻﺕ ﺍﳌﻮﺍﺩ ﻭﺟﺪ ﺃﻥ ﺃﻛﺜﺮ ﻫﺬﻩ ﺍﻷﻧﻮﺍﻉ ﺍﺳـﺘﺨﺪﺍﻣﺎ‬ ‫ﻫﻮ ﻣﻘﺎﻳﻴﺲ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻜﻬﺮﺑﻴﺔ ﺷﻜﻞ ) ‪ ١٤-١‬ﺇﱃ ‪( ١٨ -١‬ﻭﺫﻟﻚ ﻟﺴﻬﻮﻟﺔ ﺍﺳـﺘﻌﻤﺎﳍﺎ ﻭﻣﻼﺀﻣﺘـﻬﺎ‬ ‫ﻟﻠﻈﺮﻭﻑ ﺍﳌﺨﺘﻠﻔﺔ ﻟﻠﺘﺤﻤﻴﻞ‪ .‬ﺃﻣﺎ ﺍﻟﻨﻮﻋﺎﻥ ﺍﻵﺧﺮﺍﻥ ﻓﺈﻥ ﺍﺳﺘﻌﻤﺎﳍﻤﺎ ﳏﺪﻭﺩ ﻟﻮﺟﻮﺩ ﺻﻌﻮﺑﺎﺕ ﻣﺘﻌـﺪﺩﺓ‬ ‫ﻣﺜﻞ ﻛﱪ ﺣﺠﻢ ﺍﳌﻘﻴﺎﺱ ﻭﺻﻌﻮﺑﺔ ﺍﻟﺘﺸﻐﻴﻞ ﻭﺍﻟﺘﻨﺎﺳﺐ ﺑﲔ ﻛﻞ ﻣﻦ ﺍﶈﺎﺛﺔ ﻭﺍﻟﺴﻌﺔ ﻭﺍﻻﻧﻔﻌـﺎﻝ ﰱ ﻣـﺪﻯ‬ ‫ﺻﻐﲑ‪.‬‬ ‫‪B1C+( B ?':,# @A‬‬

‫ﻭ ﻳﺘﻜﻮﻥ ﻣﻦ ﺳﻠﻚ ﻗﺼﲑ ﻣﻮﺿﻮﻉ ﺑﲔ ﻃﺒﻘﺘﲔ ﻣﻦ ﺍﻟﻮﺭﻕ ﺍﻭ ﺍﻟﺒﻼﺳﺘﻴﻚ ﻭ ﲣﺘﺎﺭ ﺍﳌﺎﺩﺓ ﺍﻟﱴ ﻳﺼﻨﻊ ﻣﻨﻬﺎ‬ ‫ﺍﻟﺴﻠﻚ ﲝﻴﺚ ﺗﻜﻮﻥ ﺍﻟﻨﺴﺒﺔ ﺑﲔ ﺍﻟﺘﻐﲑ ﰲ ﺍﳌﻘﺎﻭﻣﺔ ﻭ ﺍﻟﺘﻐﲑ ﰱ ﺍﻻﻧﻔﻌﺎﻝ ﺛﺎﺑﺘﺔ ﻭ ﻫﺬﻩ ﺍﻟﻨـﺴﺒﺔ ﺗـﺴﻤﻰ‬ ‫ﻋﺎﻣﻞ ﺍﳌﻘﻴﺎﺱ )‪ (Gage Factor‬ﻭ ﺃﻛﺜﺮ ﺍﳌﻮﺍﺩ ﺍﺳﺘﻌﻤﺎﻻ ﰱ ﺻﻨﻊ ﻫﺬﻩ ﺍﳌﻘﺎﻳﻴﺲ ﻫﻮ ﺳـﺒﻴﻜﺔ ﻣـﻦ‬ ‫ﺍﻟﻨﺤﺎﺱ ﻭ ﺍﻟﻨﻴﻜﻞ ﻭ ﻳﺘﺮﺍﻭﺡ ﻃﻮﻝ ﺍﳌﻘﻴﺎﺱ ﻣﻦ ‪ ١٥٠ – ١,٥‬ﻣﻢ ﻭ ﳊﻤﺎﻳﺔ ﺳـﻠﻚ ﺍﳌﻘﻴـﺎﺱ ﺃﺛﻨـﺎﺀ‬ ‫ﺍﻻﺳﺘﻌﻤﺎﻝ ﻣﻦ ﺍﺧﺘﻼﻑ ﺩﺭﺟﺔ ﺍﳊﺮﺍﺭﺓ ﻳﻮﺿﻊ ﻏﻄﺎﺀ ﻓﻮﻕ ﺍﳌﻘﻴﺎﺱ ﻭﻳﻨﺘﻬﻲ ﺳـﻠﻚ ﺍﳌﻘﻴـﺎﺱ ﺑﻄـﺮﰲ‬ ‫ﺗﻮﺻﻴﻞ ﻟﺘﻮﺻﻴﻞ ﺍﳌﻘﻴﺎﺱ ﺑﺪﺍﺋﺮﺓ ﺍﳌﻘﻴﺎﺱ ﺍﳋﺎﺭﺟﻴﺔ‪ .‬ﻭ ﳚﺐ ﺍﻥ ﻳﻜﻮﻥ ﻣﺴﺎﺣﺔ ﻣﻘﻄﻊ ﻃـﺮﰲ ﺍﻟﺘﻮﺻـﻴﻞ‬ ‫ﺍﻛﱪ ﺑﻜﺜﲑ ﻣﻦ ﻣﺴﺎﺣﺔ ﻣﻘﻄﻊ ﺳﻠﻚ ﺍﳌﻘﻴﺎﺱ ﻭ ﻳﻨﺘﻬﻲ ﺳﻠﻚ ﺍﻟﻘﻴﺎﺱ ﺣﱴ ﺗﻜﻮﻥ ﻣﻘﺎﻭﻣﺘـﻬﺎ ﺻـﻐﲑﺓ ﻭ‬ ‫ﳝﻜﻦ ﳊﺎﻣﻬﺎ ﺍﻭ ﺗﻮﺻﻴﻠﻬﺎ ﺑﺪﺍﺋﺮﺓ ﺍﳌﻘﻴﺎﺱ‪ .‬ﻭ ﻋﻨﺪ ﺍﻻﺳﺘﻌﻤﺎﻝ ﻳﻠﺼﻖ ﺍﳌﻘﻴﺎﺱ ﻋﻠﻰ ﺍﳉﺴﻢ ﺍﳌﺨﺘﱪ ﲝﻴـﺚ‬ ‫ﺍﺫﺍ ﺣﺪﺙ ﺍﻧﻔﻌﺎﻝ ﺑﺎﳉﺴﻢ ﻓﺎﻧﻪ ﻳﻨﺘﻘﻞ ﲤﺎﻣﺎ ﺇﱃ ﻣﻘﻴﺎﺱ ﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻜﻬﺮﺑﺎﺋﻲ ﻭ ﳛﺪﺙ ﺑﻪ ﻧﻔﺲ ﺍﻻﻧﻔﻌﺎﻝ ‪.‬‬ ‫ﻭ ﳚﺐ ﺍﻥ ﻳﺘﻢ ﺗﻨﻈﻴﻒ ﺍﻟﺴﻄﺢ ﺍﻟﺬﻱ ﺳﻴﻠﺼﻖ ﻋﻠﻴﻪ ﺍﳌﻘﻴﺎﺱ ﺑﺼﻨﻔﺮﺓ ﻣﺘﻮﺳـﻄﺔ ﺍﳋـﺸﻮﻧﺔ ﰒ ﻳﻨﻈـﻒ‬ ‫ﺑﻮﺍﺳﻄﺔ ﻗﻄﻌﺔ ﻣﻦ ﺍﻟﻘﻄﻦ ﻣﺒﻠﻠﺔ ﺑﺎﻷﺳﻴﺘﻮﻥ‪ .‬ﻭ ﺗﻮﺿﻊ ﺍﳌﺎﺩﺓ ﺍﻟﻼﺻﻘﺔ ﻋﻠﻰ ﺳﻄﺢ ﺍﳉﺴﻢ ﺍﻟﺬﻱ ﰎ ﺇﻋﺪﺍﺩﻩ‬ ‫ﺑﻜﻤﻴﺔ ﻛﺎﻓﻴﺔ ﳌﻨﻊ ﺣﺪﻭﺙ ﺟﻴﻮﺏ ﻫﻮﺍﺋﻴﺔ ﲢﺖ ﺍﳌﻘﻴﺎﺱ ﰒ ﻳﺜﺒﺖ ﺍﻟﻘﻴﺎﺱ ﻭ ﻳﻀﻐﻂ ﻋﻠﻴﻪ ﺣﱴ ﻳﺘﻢ ﺗﺜﺒﻴﺘﻪ ﻭ‬ ‫ﻳﺘﺮﻙ ﳌﺪﺓ ﺗﺘﺮﺍﻭﺡ ﺑﲔ ﻳﻮﻡ ﺍﻭ ﻳﻮﻣﲔ ﺣﱴ ﲡﻒ ﺍﳌﺎﺩﺓ ﺍﻟﻼﺻﻘﺔ ‪.‬‬ ‫ﻭ ﺍﻟﻔﻜﺮﺓ ﺍﳌﺒﲎ ﻋﻠﻴﻬﺎ ﻣﻘﻴﺎﺱ ﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻜﻬﺮﺑﺎﺋﻲ ﺍﻧﻪ ﺑﻌﺪ ﲤﺎﻡ ﻟﺼﻘﻪ ﺇﺫﺍ ﺣﺪﺙ ﺍﻧﻔﻌﺎﻝ ﺑﺎﳉﺴﻢ ﻓﺎﻧـﻪ‬ ‫ﻳﻨﺘﻘﻞ ﲤﺎﻣﺎ ﺇﱃ ﻣﻘﻴﺎﺱ ﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻜﻬﺮﺑﺎﺋﻲ ﻭ ﳛﺪﺙ ﺑﻪ ﻧﻔﺲ ﺍﻻﻧﻔﻌﺎﻝ ﻓـﻴﻐﲑ ﺍﳌﻘﺎﻭﻣـﺔ ﺍﻟﻜﻬﺮﺑﺎﺋﻴـﺔ‬ ‫ﻟﻠﺴﻠﻚ‪:‬‬ ‫‪∆R‬‬ ‫‪R‬‬

‫ﺗﺘﻨﺎﺳﺐ ﻣﻊ‬

‫‪٢٦‬‬

‫‪∆L‬‬ ‫‪L‬‬


‫ﺣﻴﺚ‬ ‫‪ = ∆L‬ﺍﻟﺘﻐﲑ ﰲ ﻃﻮﻝ ﺍﻟﺴﻠﻚ ‪L‬‬ ‫‪ = ∆R‬ﺍﻟﺘﻐﲑ ﰲ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺴﻠﻚ ‪R‬‬

‫ﺍﻻﻧﻔﻌﺎﻝ =‬

‫‪∆R ∆L‬‬ ‫=‬ ‫‪R‬‬ ‫‪L‬‬

‫× ﺛﺎﺑﺖ‬

‫ﻭ ﺍﻟﺜﺎﺑﺖ ﻏﺎﻟﺒﺎ ﻳﻌﻄﻰ ﻣﻊ ﺍﳉﻬﺎﺯ ﺃﻭ ﻋﻠﻰ ﺍﳌﻘﻴﺎﺱ ﻧﻔﺴﻪ ﻭﻳﻌﻄﻰ ﺍﳉﻬﺎﺯ ﻗﻴﻤﺔ ﺍﻻﻧﻔﻌﺎﻝ ﻣﺒﺎﺷـﺮﺓ ﺷـﻜﻞ‬ ‫)‪(١٧-١‬‬ ‫‪: ?':,D( B1C+( @A AE‬‬

‫• ﺻﻐﲑ ﺍﳊﺠﻢ ﻻ ﻳﺘﻌﺪﻯ ﺣﺠﻢ ﻃﺎﺑﻊ ﺍﻟﱪﻳﺪ‬ ‫• ﻳﻘﻴﺲ ﺍﻻﻧﻔﻌﺎﻝ ﻣﺒﺎﺷﺮﺓ ﻣﻦ ﻗﻴﺎﺱ ﺍﻟﺘﺸﻜﻞ ﺍﻟﻄﻮﱄ ﻟﻌﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ‬ ‫• ﻳﺴﻬﻞ ﻟﺼﻘﻬﺎ ﻋﻠﻰ ﺍﳉﺴﻢ ﺍﳌﺨﺘﱪ‬ ‫• ﺩﺭﺟﺔ ﺣﺴﺎﺳﻴﺘﻬﺎ ﻋﺎﻟﻴﺔ ﻗﺪ ﺗﺼﻞ ﺍﱃ ﻗﻴﺎﺱ ﺍﻧﻔﻌﺎﻝ ﺣﱴ ‪ -٦ ^ ١٠‬ﻣﻢ‪ /‬ﻣـﻢ ﻭﻻ ﳝﻜـﻦ ﺍﻥ‬ ‫ﺗﺼﻞ ﺇﻟﻴﻬﺎ ﺍﻷﺟﻬﺰﺓ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﺍﻭ ﺍﻟﻀﻮﺋﻴﺔ‬ ‫• ﳝﻜﻦ ﻗﻴﺎﺱ ﺍﻻﻧﻔﻌﺎﻻﺕ ﺍﻟﺪﻳﻨﺎﻣﻴﻜﻴﺔ ﺣﻴﺚ ﻻ ﳝﻜﻦ ﻟﻸﺟﻬﺰﺓ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻭﺍﻟﻀﻮﺋﻴﺔ ﻗﻴﺎﺳﻬﺎ ‪.‬‬

‫ﻣﻘﻴﺎﺱ ﺍﻻﻧﻔﻌﺎﻝ‬

‫‘‪@ @óiŠè×@ÞbÈÐãa@÷bîÔß@HQT–QI@ÝØ‬‬

‫‪٢٧‬‬


@ @HñØßI@òîiŠè×@ÞbÈÐãa@îíbÔß@HQU–QI@ÝØ‘

@ @óiŠèØÛa@ÞbÈÐãüa@÷bîÔß@ÝàÇ@ñŠØÏ@HQV–QI@ÝØ‘

٢٨


@ @ÞbÈÐãüa@÷bîÓ@‹bèu@HQW@MQI@ÝØ‘

@ @òĐÔã@åß@Šr×c@†äÇ@ÞbÈÐãüa@÷bîÔÛ@Éîà£@‹bèu@QXMQ@ÝØ‘ @@

٢٩


‫@@‬ ‫@@‬ ‫@@‬ ‫@@‬

‫‪٣٠‬‬

‫ אصא אدوאא ‪K‬د‪ L‬دم‪ J‬م‪K‬د‪ J L‬د‪L‬‬

‫ ‬ ‫ ‪ # $%‬‬ ‫‪ 1-2‬‬

‫ﻳﻌﺘﱪ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﺍﻻﺳﺘﺎﺗﻴﻜﻲ ﰱ ‪ æ@ …b;È½a‬ﻣﻦ ﺃﻫﻢ ﻭﺃﻛﺜﺮ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺷﻴﻮﻋﹰﺎ ﻭﺍﺳﺘﺨﺪﺍﻣﹰﺎ ﺧﺎﺻﺔ ﺃﻧﻪ ﻣﻦ‬ ‫ﺃﺳﻬﻞ ﻭﺃﺑﺴﻂ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﰱ ﺇﺟﺮﺍﺋﻪ ﻭﻣﻦ ﺃﺩﻗﻬﺎ ﰱ ﲢﺪﻳﺪ ﺍﻟﻨﺘﺎﺋﺞ‪ .‬ﻛﻤﺎ ﺗـﺴﺘﻨﺪ ﻣﻌﻈـﻢ‬ ‫ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﺇﱃ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻛﺄﺳﺎﺱ ﻟﺒﻴﺎﻥ ﺧﻮﺍﺹ ﺍﳌﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ﳌﺎ ﻟﻨﺘﺎﺋﺠﻪ ﻣﻦ ﻗﻴﻤﺔ ﻭﺩﻻﻟـﺔ‬ ‫ﻫﺎﻣﺔ ﰱ ﲢﺪﻳﺪ ﻫﺬﻩ ﺍﳋﻮﺍﺹ ﻻ ﺳﻴﻤﺎ ﻭﺃﻥ ﻟﻠﻤﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ﻗﺪﺭﺓ ﻋﺎﻟﻴﺔ ﻋﻠﻰ ﲢﻤﻞ ﺃﲪـﺎﻝ ﺍﻟـﺸﺪ ﳑـﺎ‬ ‫ﻳﺴﺘﻠﺰﻡ ﺍﺧﺘﺒﺎﺭﻫﺎ ﰱ ﺍﻟﺸﺪ ﻟﺒﻴﺎﻥ ﻣﺪﻯ ﲢﻤﻠﻬﺎ ﺃﺛﻨﺎﺀ ﺍﻟﺘﺸﻐﻴﻞ‪ .‬ﻭﻳﻌﺘﱪ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻣﻦ ﺃﻫﻢ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ‬ ‫ﺍﻟﱴ ﺗﺴﺘﺨﺪﻡ ﰱ ﺿﺒﻂ ﺟﻮﺩﺓ ﺍﳌﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ﻧﻈﺮﹰﺍ ﻟﻮﺟﻮﺩ ﻋﻼﻗﺔ ﺑﲔ ﺧﻮﺍﺹ ﺍﻟـﺸﺪ ﻭﺑـﲔ ﺍﳋـﻮﺍﺹ‬ ‫ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﺍﻷﺧﺮﻯ ﻟﺘﻠﻚ ﺍﳌﻮﺍﺩ‪ .‬ﻟﺬﻟﻚ ﻓﺈﻥ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﳚﺮﻯ ﻟﻠﻤﻮﺍﺩ ﺍﳊﺪﻳﺪﻳﺔ ﻭﻏﲑ ﺍﳊﺪﻳﺪﻳﺔ ﻭﲡﺪﺭ‬ ‫ﺍﻹﺷﺎﺭﺓ ﺃﻥ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻧﺎﺩﺭﹰﺍ ﻣﺎ ﳚﺮﻯ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﻏﲑ ﺍﳌﻌﺪﻧﻴﺔ )ﻣﺜﻞ ﺍﳋﺮﺳﺎﻧﺔ( ﻧﻈﺮﹰﺍ ﻟﻀﻌﻔﻬﺎ ﰱ ﲢﻤﻞ‬ ‫ﺍﻟﺸﺪ ﻭﻷﻥ ﻋﻤﻠﻬﺎ ﰱ ﺍﳌﻨﺸﺂﺕ ﻫﻰ ﻟﺘﺤﻤﻞ ﺃﲪﺎﻝ ﺍﻟﻀﻐﻂ‪ .‬ﻭﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﺍﻻﺳﺘﺎﺗﻴﻜﻲ ﳚﺮﻯ ﲢﺖ ﺗﺄﺛﲑ‬ ‫ﲪﻞ ﺷﺪ ﳏﻮﺭﻯ ﰱ ﺇﲡﺎﻩ ﻭﺍﺣﺪ ﺣﻴﺚ ﻳﻨﻄﺒﻖ ﺇﲡﺎﻩ ﺍﳊﻤﻞ ﻋﻠﻰ ﺍﶈﻮﺭ ﺍﻟﻄﻮﱃ ﻟﻌﻴﻨﺔ ﺍﻻﺧﺘﺒـﺎﺭ‪ ،‬ﲝﻴـﺚ‬ ‫ﻳﻜﻮﻥ ﺍﻟﺘﺤﻤﻴﻞ ﺗﺪﺭﳚﻴﺎ ﻣﻦ ﺍﻟﺼﻔﺮ ﺣﱴ ﺍﻻ‪‬ﻴﺎﺭ ﻟﻌﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ‪.‬‬ ‫‪ !" 2-2‬‬

‫ﻟﺪﺭﺍﺳﺔ ﺳﻠﻮﻙ ﺍﳌﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ﻭﲢﺪﻳﺪ ﺧﺼﺎﺋﺼﻬﺎ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﲢﺖ ﺗﺄﺛﲑ ﲪﻞ ﺍﻟـﺸﺪ ﺃﳘﻴـﺔ ﺧﺎﺻـﺔ ﻭ‬ ‫ﺑﺎﻷﺧﺺ ﻟﻠﻤﻮﺍﺩ ﺍﳌﻄﻴﻠﺔ ﻭﻓﻴﻤﺎ ﻳﻠﻲ ﺳﻴﺘﻢ ﺇﻥ ﺷﺎﺀ ﺍﷲ ﺩﺭﺍﺳﺔ ﺳﻠﻮﻙ ﺍﳌﻌﺎﺩﻥ ﺑﺄﻧﻮﺍﻋﻬﺎ ﺍﻟﺜﻼﺙ‪ :‬ﺍﳌﻄﻴﻠﺔ ﻭ‬ ‫ﻧﺼﻒ ﺍﳌﻄﻴﻠﺔ ﻭﺍﻟﻘﺼﻔﺔ‪.‬‬ ‫‪Ductile Materials@òÜîĐ½a@òîã†È½a@…aì½a@ÚìÜ@òa‰…@QMRMR‬‬

‫ﻋﻨﺪﻣﺎ ﺗﺘﻌﺮﺽ ﻋﻴﻨﺔ ﺇﺳﻄﻮﺍﻧﻴﺔ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﻟﻄﺮﻯ ﺃﻯ ﻣﻦ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﺇﱃ ﲪﻞ ﺷـﺪ )‪ (P‬ﻳﺘﺰﺍﻳـﺪ‬ ‫ﺗﺪﺭﳚﻴﺎ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺸﻜﻞ )‪ ،(١-٢‬ﻓﺈﻥ ﺍﻟﻌﻴﻨﺔ ﺍﶈﻤﻠﺔ ﳛﺪﺙ ‪‬ﺎ ﺍﺳﺘﻄﺎﻟﺔ ﺗﺘﺰﺍﻳﺪ ﺑﺰﻳﺎﺩﺓ ﺍﳊﻤﻞ‪.‬‬

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‫‪A‬‬ ‫‪A1‬‬

‫‪P‬‬ ‫‪∆L‬‬

‫‪L‬‬

‫‪L1‬‬

‫‘‪@ @†’Ûbi@ÝîàznÛa@HQMRI@ÝØ‬‬

‫ﻓﺈﺫﺍ ﰎ ﻗﻴﺎﺱ ﻗﻴﻤﺔ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ )‪ (P‬ﻭﻗﻴﻤﺔ ﺍﻻﺳﺘﻄﺎﻟﺔ )‪ (∆L‬ﺍﳌﻘﺎﺑﻠﺔ ﻟﻜﻞ ﲪﻞ ﻭﰎ ﺗـﺪﻭﻳﻦ ﺍﻟﻨﺘـﺎﺋﺞ‬ ‫ﻭﺭﺳﻢ ﻋﻼﻗﺔ ﺑﲔ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﻛﺎﳌﺒﻴﻨﺔ ﺑﺸﻜﻞ )‪ ،(٢-٢‬ﻓﺈﻧﻨﺎ ﳒﺪ ﺃﻥ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻭﺍﻻﺳـﺘﻄﺎﻟﺔ‬ ‫ﻣﺘﻨﺎﺳﺒﺎﻥ ﺣﱴ ﻧﻘﻄﺔ )‪ (A‬ﻋﻠﻰ ﻣﻨﺤﻰ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ‪ ،‬ﻭﺇﺫﺍ ﺍﺳﺘﻤﺮ ﰱ ﺍﻟﺘﺤﻤﻴﻞ ﺑﻌﺪ ﺍﻟﻨﻘﻄـﺔ )‪(A‬‬

‫ﻓﺈﻥ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺗﺰﺩﺍﺩ ﻭﺑﺴﺮﻋﺔ ﺣﱴ ﲡﺪ ﺃﻧﻪ ﻋﻨﺪ ﺍﳊﻤﻞ ﺍﳌﻘﺎﺑﻞ ﻟﻠﻨﻘﻄﺔ )‪ (B‬ﲢﺪﺙ ﺍﺳﺘﻄﺎﻟﺔ ﻛﺒﲑﺓ ﺫﺍﺕ‬ ‫ﻗﻴﻤﺔ ﻣﻠﺤﻮﻇﺔ ﻭﺗﺴﺘﻤﺮ ﺍﻻﺳﺘﻄﺎﻟﺔ ﰱ ﺍﻟﺰﻳﺎﺩﺓ ﻣﻊ ﺛﺒﻮﺕ ﺍﳊﻤﻞ ﻭﺗﺴﻤﻰ ﻫﺬﻩ ﺍﳊﺎﻟﺔ ﺧﻀﻮﻉ ﺍﳌﻌﺪﻥ ﻛﻤﺎ‬ ‫ﺗﺴﻤﻰ ﺍﻟﻨﻘﻄﺔ )‪ (B‬ﺑﻨﻘﻄﺔ ﺍﳋﻀﻮﻉ‪ .‬ﻭﺇﺫﺍ ﺍﺳﺘﻤﺮ ﰱ ﺍﻟﺘﺤﻤﻴﻞ ﺑﺰﻳﺎﺩﺓ ﺍﳊﻤﻞ ﲢﺪﺙ ﺍﺳﺘﻄﺎﻟﺔ ﻣـﺼﺎﺣﺒﺔ‬ ‫ﻟﻜﻞ ﲪﻞ ﻭﻟﻜﻨﻬﺎ ﺗﻜﻮﻥ ﺳﺮﻳﻌﺔ ﻭﲟﻌﺪﻝ ﺃﻛﱪ ﳑﺎ ﻛﺎﻥ ﳛﺪﺙ ﰱ ﺍﳌﻨﻄﻘﺔ )‪ (0–A‬ﻛﻤـﺎ ﺃﻥ ﺍﻻﺳـﺘﻄﺎﻟﺔ‬ ‫ﺗﺼﺒﺢ ﻏﲑ ﻣﺘﻨﺎﺳﺒﺔ ﻣﻊ ﺍﳊﻤﻞ ﻭﻳﻜﻮﻥ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﻋﻠﻰ ﻫﻴﺌﺔ ﻣﻨﺤﲎ ﻭﻟﻴﺲ ﺧﻂ ﻣﺴﺘﻘﻴﻢ ﻛﻤـﺎ‬ ‫ﺑﺎﻟﺸﻜﻞ )‪ (٢-٢‬ﻭﺍﳌﺒﲔ ﺑﺎﳉﺰﺀ )‪ (B-C‬ﻭﺫﻟﻚ ﺣﱴ ﻧﻘﻄﺔ )‪ (C‬ﺣﻴﺚ ﺗﺼﻞ ﺇﱃ ﺃﻗﺼﻰ ﲪـﻞ ﻟﻠﻌﻴﻨـﺔ‬ ‫ﺍﳌﺨﺘﱪﺓ‪ .‬ﻭﺧﻼﻝ ﺍﻟﺘﺤﻤﻴﻞ ﰱ ﺍﳌﻨﻄﻘﺔ )‪ .(B-C‬ﻓﺈﻥ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﻌﻴﻨﺔ ﻳﺘﻨﺎﻗﺺ ﺗﻘﺮﻳﺒـﹰﺎ ﺑـﻨﻔﺲ‬ ‫ﺍﻟﻨﺴﺒﺔ ﺍﻟﱴ ﻳﺘﺰﺍﻳﺪ ‪‬ﺎ ﻃﻮﻟﻴﹰﺎ ﻭﻟﻜﻦ ﺑﻌﺪ ﺍﻟﺘﺤﻤﻴﻞ ﺑﺎﳊﻤﻞ ﺍﻷﻗﺼﻰ ﻣﺒﺎﺷﺮﺓ ﺃﻯ ﺑﻌﺪ ﻧﻘﻄﺔ )‪ (C‬ﻣﺒﺎﺷـﺮﺓ‬ ‫ﳛﺪﺙ ﺗﺮﻛﺰ ﰱ ﺍﻟﺘﻐﲑ ﰱ ﻣﻘﻄﻊ ﺍﻟﻌﻴﻨﺔ ﻋﻠﻰ ﻃﻮﻝ ﻗﺼﲑ ﻣﻨﻬﺎ ﻭﻳﺘﻜﻮﻥ ﻧﺘﻴﺠﺔ ﻟﺬﻟﻚ ﺭﻗﺒﺔ ﻟﻠﻌﻴﻨﺔ ﺗﻜـﻮﻥ‬ ‫ﻋﺎﺩﺓ ﰱ ﻣﻨﻄﻘﺔ ﻋﺪﻡ ﺍﻟﺘﺠﺎﻧﺲ ﻭﺍﻻﻧﺘﻈﺎﻡ ﻟﻠﻤﻌﺪﻥ ﺃﻯ ﳛﺪﺙ ﰱ ﻣﻨﻄﻘﺔ ﺿﻌﻒ ﺍﳌﻌﺪﻥ ﻭﻫـﺬﺍ ﺍﻟـﻨﻘﺺ‬ ‫ﺍﻟﻜﺒﲑ ﰱ ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﻌﻴﻨﺔ ﻻ ﳝﻜﻨﻬﺎ ﻣﻦ ﲢﻤﻞ ﺃﲪﺎﻝ ﺃﻛﱪ ﻣﻦ ﺍﻟﻘﻴﻤﺔ ﺍﳌﻌﺮﺿﺔ ﳍﺎ ﺍﻟﻌﻴﻨﺔ‬ ‫ﻋﻨﺪ ﺍﻟﻨﻘﻄﺔ )‪ (C‬ﻟﺬﻟﻚ ﻟﻜﻰ ﲢﺘﻔﻆ ﺍﻟﻌﻴﻨﺔ ﺑﺎﻟﺘﻮﺍﺯﻥ ﺑﲔ ﺍﳊﻤﻞ ﻭﻣﻘﺎﻭﻣﺘﻬﺎ ﳍﺬﺍ ﺍﳊﻤﻞ ﻓﺈﻥ ﺍﳊﻤﻞ ﻳﻘـﻞ‬ ‫ﻋﻨﺪ ﺍﻟﻨﻘﻄﺔ )‪ (D‬ﻭﻳﻜﻮﻥ ﻣﺼﺤﻮﺑﹰﺎ ﺑﺰﻳﺎﺩﺓ ﻛﺒﲑﺓ ﰱ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻭﻳﺴﺘﻤﺮ ﺍﻟﺘﺤﻤﻴﻞ ﰱ ﺍﻟﺘﻨﺎﻗﺺ ﻭﺍﻟﻌﻴﻨﺔ ﰱ‬ ‫ﺍﻻﺳﺘﻄﺎﻟﺔ ﺣﱴ ﳛﺪﺙ ﺍﻟﻜﺴﺮ ﻟﻠﻌﻴﻨﺔ ﻋﻨﺪ ﺍﻟﻨﻘﻄﺔ )‪ (D‬ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﲟﻨﺤﻰ ﺍﻟﺸﻜﻞ )‪ .(٢-٢‬ﻭﳝﻜﻦ‬ ‫ﺗﻔﺴﲑ ﺑﻌﺾ ﺍﻟﻈﻮﺍﻫﺮ ﺍﻟﱴ ﲢﺪﺙ ﻷﻯ ﻣﻌﺪﻥ ﻣﻄﻴﻞ ﻣﻦ ﳊﻈﺔ ﺑﺪﺍﻳﺔ ﺍﻟﺘﺤﻤﻴﻞ ﺣﱴ ﺍﻻ‪‬ﻴﺎﺭ ﻓﻴﻤﺎ ﻳﻠﻰ‪:‬‬

‫‪٣٢‬‬


‫ﺍﳊﻤﻞ‬

‫‪C‬‬ ‫‪D‬‬ ‫‪A B‬‬

‫ﺍﻻﺳﺘﻄﺎﻟﺔ‬

‫‘‪@ @@ÝîĐß@æ†È½@òÛbĐnüaë@Ýà§a@óäzäß@@HRMRI@ÝØ‬‬

‫‪ -1‬‬ ‫ﳛﺪﺙ ﺍﳋﻀﻮﻉ ﺑﺎﳌﻌﺪﻥ ﻋﻨﺪ ﺍﺗﺴﺎﻉ ﺍﳌﺴﺎﻓﺔ ﺑﲔ ﺫﺭﺍﺕ ﺟﺰﻳﺌﺎﺗﻪ ﻟﺪﺭﺟﺔ ﺗﻜﺴﺮ ﺍﺭﺗﺒﺎﻁ ﺍﻟـﺬﺭﺍﺕ ﳑـﺎ‬ ‫ﻳﺴﺒﺐ ﺗﻐﲑﹰﺍ ﰱ ﺍﻟﻮﺿﻊ ﺑﲔ ﺍﻟﺬﺭﺍﺕ ﺑﻌﻀﻬﺎ ﺍﻟﺒﻌﺾ ﺃﻯ ﳛﺪﺙ ﺗﻐﲑ ﰱ ﺧﻄﻮﻁ ﺗﺸﺎﺑﻜﻬﺎ ﻭﻳﻜﻮﻥ ﺫﻟـﻚ‬ ‫ﻣﺼﺤﻮﺏ ﺑﺎﻧﺰﻻﻕ ﻋﻠﻰ ﻣﺴﺘﻮﻳﺎﺕ ﺩﺍﺧﻞ ﺍﳉﺰﻳﺌﺎﺕ ﻭﻫﻰ ﺍﳌﺴﺘﻮﻳﺎﺕ ﺍﻟﻀﻌﻴﻔﺔ ﰱ ﺍﻟﺘﻤﺎﺳـﻚ ﺧـﻼﻝ‬ ‫ﺍﳉﺰﻳﺌﺎﺕ‪ .‬ﻭﺗﺘﻮﻗﻒ ﻫﺬﻩ ﺍﳌﺴﺘﻮﻳﺎﺕ ﻋﻠﻰ ﻛﻴﻔﻴﺔ ﺗﺮﺗﻴﺐ ﺍﻟﺬﺭﺍﺕ ﺑﺎﻟﺸﺒﻜﺔ ﺍﳊﻴﺰﻳﺔ ﻟﻠﺠﺰﻳﺌـﺎﺕ ﻭﻫـﺬﺍ‬ ‫ﺍﻟﺘﺮﺗﻴﺐ ﳜﺘﻠﻒ ﻣﻦ ﻣﻌﺪﻥ ﻵﺧﺮ‪ ،‬ﻭﻋﻤﻮﻣﺎ ﻳﻨﺘﺞ ﻣﻦ ﺍﻧﺰﻻﻕ ﺍﳉﺰﻳﺌﺎﺕ ﻋﻠﻰ ﺑﻌﻀﻬﺎ ﺍﺳﺘﻄﺎﻟﺔ ﻛﺒﲑﺓ ﻛﻤﺎ‬ ‫ﻫﻮ ﻳﺒﲔ ﺑﺸﻜﻞ )‪.(٣-٢‬‬

‫ ا‬

‫ ا‬

‫ﻣﺴﺘﻮﻯ ﺍﻻﻧﺰﻻﻕ‬

‫‘‪@ @ô‰ìª@†’Û@ò™ŠÈß@ñ‰ìÜi@åß@õŒu@ÖüŒãg@HSMRI@ÝØ‬‬

‫‪٣٣‬‬


‫ﻭﻳﻌﺘﱪ ﺧﻀﻮﻉ ﺍﳌﻌﺪﻥ ﻫﻮ ﺣﺎﻟﺔ ﻋﺪﻡ ﺗﻮﺍﺯﻥ ﺩﺍﺧﻠﻰ ﺗﺴﺒﺐ ﺍﻻﻧﺰﻻﻕ ﻟﻔﺘﺮﺓ ﺯﻣﻨﻴﺔ ﻗﺼﲑﺓ ﺣـﱴ ﻳـﺼﻞ‬ ‫ﺍﳌﻌﺪﻥ ﳊﺎﻟﺔ ﺍﻻﺗﺰﺍﻥ ﻧﺘﻴﺠﺔ ﻇﺎﻫﺮﺓ ﺍﻟﺘﺼﻠﺪ ﺍﻻﻧﻔﻌﺎﱃ‪ ،‬ﰒ ﺑﻌﺪ ﺫﻟﻚ ﳛﺪﺙ ﺍﳋﻀﻮﻉ ﰱ ﻣﻨﻄﻘﺔ ﻣـﺎ ﻣـﻦ‬ ‫ﺍﻟﻌﻴﻨﺔ ﺣﱴ ﺗﺼﻞ ﻣﺮﺓ ﺃﺧﺮﻯ ﺇﱃ ﺣﺎﻟﺔ ﺍﻟﺘﺼﻠﺪ ﺍﻻﻧﻔﻌﺎﱃ ﻓﻴﺘﻮﻗﻒ ﺍﳋﻀﻮﻉ ﰱ ﻫﺬﻩ ﺍﳌﻨﻄﻘـﺔ ﻭﻳﺒـﺪﺃ ﰱ‬ ‫ﻣﻨﻄﻘﺔ ﺃﺧﺮﻯ ﻣﻦ ﺍﳌﻌﺪﻥ ﻭﻫﻜﺬﺍ ﺣﱴ ﳛﺪﺙ ﻟﻠﻤﻌﺪﻥ ﻛﻠﻪ ﺗﺼﻠﺪ ﺇﻧﻔﻌﺎﱃ ﻳﻮﻗﻒ ﺍﳋﻀﻮﻉ ﺑﺎﳌﻌﺪﻥ ﻛﻠﻪ‪.‬‬

‫‪ -2‬‬ ‫ﳝﻜﻦ ﺗﻔﺴﲑ ﻇﺎﻫﺮﺓ ﺍﻟﺘﺼﻠﺪ ﺍﻻﻧﻔﻌﺎﱃ ﰱ ﺃﻧﻪ ﺃﺛﻨﺎﺀ ﺣﺮﻛﺔ ﺍﻻﻧﺰﻻﻕ ﻟﻠﺠﺰﻳﺌﺎﺕ ﻓﺈ‪‬ﺎ ﺗﻨﻜﺴﺮ ﺇﱃ ﺃﺟـﺰﺍﺀ‬ ‫ﺧﺼﻮﺻﹰﺎ ﻗﺮﺏ ﺍﳊﺪﻭﺩ ﺍﻷﺻﻠﻴﺔ ﻟﻠﺠﺰﻳﺌﺎﺕ ﺣﻴﺚ ﺗﺘﺪﺍﺧﻞ ﺧﻄﻮﻁ ﻫﺬﻩ ﺍﻷﺟﺰﺍﺀ ﺑﻌﻀﻬﺎ ﻣـﻊ ﺍﻵﺧـﺮ‬ ‫ﻣﺴﺒﺒﺔ ﻣﻘﺎﻭﻣﺔ ﻣﺘﺰﺍﻳﺪﺓ ﻟﻼﻧﺰﻻﻕ‪ .‬ﻭﺑﺎﻹﺿﺎﻓﺔ ﺇﱃ ﺫﻟﻚ ﻓﺈﻥ ﻣﺴﺘﻮﻳﺎﺕ ﺍﻻﻧﺰﻻﻕ ﺫﺍﺕ ﺍﲡﺎﻫﺎﺕ ﳐﺘﻠﻔـﺔ‬ ‫ﳉﺰﻳﺌﺎﺕ ﺍﳌﻌﺪﻥ ﺍﳌﺨﺘﻠﻔﺔ ﺣﻴﺚ ﻳﺘﺪﺍﺧﻞ ﺍﻧﺰﻻﻕ ﺟﺰﺉ ﻣﻊ ﺍﻧﺰﻻﻕ ﺍﳉﺰﺉ ﺍﻵﺧﺮ‪ ،‬ﻭﻳﻨﺘﺞ ﻋـﻦ ﺫﻟـﻚ‬ ‫ﺍﺯﺩﻳﺎﺩ ﻣﻨﺎﻃﻖ ﺍﻻﺣﺘﻜﺎﻙ ﺩﺍﺧﻞ ﺍﳌﻌﺪﻥ ﻛﻤﺎ ﻳﺴﺒﺐ ﺗﺼﻠﺪﻩ ﻭﺑﺎﻟﺘﺎﱃ ﺗﻮﻗﻒ ﺍﻻﻧﺰﻻﻕ‪.‬‬

‫‪!" -3‬‬

‫‬

‫ﳝﻜﻦ ﺗﻔﺴﲑ ﻇﺎﻫﺮﺓ ﺣﺪﻭﺙ ﺍﻟﺮﻗﺒﺔ ﺑﺄ‪‬ﺎ ﺇﻧﺰﻻﻕ ﺟﺰﻳﺌﺎﺕ ﺍﳌﻌﺪﻥ ﻋﻠﻰ ﺍﳌﺴﺘﻮﻳﺎﺕ ﺍﳌﻌﺮﺿﺔ ﺇﱃ ﺃﻛﱪ ﻗﻮﺓ‬ ‫ﻟﻠﻘﺺ ﺃﻯ ﻋﻠﻰ ﺍﳌﺴﺘﻮﻳﺎﺕ ﺍﻟﱴ ﲤﻴﻞ ‪ ٤٥‬ﺩﺭﺟﺔ ﻣﻊ ﺍﲡﺎﻩ ﲪﻞ ﺍﻟﺸﺪ‪ .‬ﻭﻫﺬﺍ ﺍﻻﻧﺰﻻﻕ ﻳﺴﺒﺐ ﻭﺟـﻮﺩ‬ ‫ﲢﻤﻴﻞ ﺷﺪ ﻏﲑ ﳏﻮﺭﻱ ﻛﻤﺎ ﰱ ﺷﻜﻞ )‪ (٤-٢‬ﻭﻟﻜﻰ ﳛﺪﺙ ﺇﺗﺰﺍﻥ ﻟﻠﻌﻴﻨﺔ ﺑﻌﺪ ﺫﻟﻚ ﻻﺑﺪ ﺃﻥ ﻳـﺼﺎﺣﺐ‬ ‫ﻫﺬﺍ ﺍﳊﻤﻞ ﻏﲑ ﺍﶈﻮﺭﻯ ﺩﻭﺭﺍﻥ ﺍﳌﺴﺘﻮﻳﺎﺕ ‪ ٤٥‬ﺩﺭﺟﺔ ﺣﱴ ﳛﺘﻔﻆ ﲟﺤﻮﺭﻳﺘﻪ‪ ،‬ﻭﻳﺘﺴﺒﺐ ﻫﺬﺍ ﺍﻟـﺪﻭﺭﺍﻥ‬ ‫ﰱ ﻧﻘﺺ ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﺃﻯ ﺣﺪﻭﺙ ﺭﻗﺒﺔ ‪‬ﺎ ﻭﻛﺬﻟﻚ ﺯﻳﺎﺩﺓ ﻛﺒﲑﺓ ﻣﻔﺎﺟﺌـﺔ‬ ‫ﰱ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻟﻠﻌﻴﻨﺔ‪.‬‬ ‫ﻩ‬

‫‪٤٥‬‬

‫ﻩ‬

‫‪٤٥‬‬

‫‘‪@ @ÉĐÔ½a@ñŠí†nß@òäîÈÛ@òjÓŠÛa@të†y@HTMR@I@ÝØ‬‬

‫‪٣٤‬‬


‫‪$%&' (' )* +%, -4‬‬ ‫ﳛﺪﺙ ﺍ‪‬ﻴﺎﺭ ﻋﻴﻨﺔ ﺍﳌﻌﺪﻥ ﺍﳌﻄﻴﻞ ﲢﺖ ﺗﺄﺛﲑ ﲪﻞ ﺍﻟﺸﺪ ﺑﺎﻟﻜﺴﺮ ﻭﺫﻟﻚ ﺑﺎﳋﻄﻮﺗﲔ ﺍﻟﺘﺎﻟﻴﺘﲔ‪:‬‬ ‫('&‬

‫‪Separation‬‬

‫ﻫﺬﻩ ﺍﳋﻄﻮﺓ ﺍﻷﻭﱃ ﻭﺍﻟﱴ ﳛﺪﺙ ﻓﻴﻬﺎ ﺍﻻﻧﻔﺼﺎﻝ ﰱ ﻣﻨﻄﻘﺔ ﻣﻨﺘﺼﻒ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻭﻫـﻰ ﻣﻨﻄﻘـﺔ‬ ‫ﺣﺪﻭﺙ ﺍﻟﺮﻗﺒﺔ ﻭﻳﻜﻮﻥ ﺫﻟﻚ ﺍﻻﻧﻔﺼﺎﻝ ﻋﻠﻰ ﻣﺴﺘﻮﻯ ﻋﻤﻮﺩﻯ ﻋﻠﻰ ﺍﲡﺎﻩ ﲪﻞ ﺍﻟﺸﺪ ﻭﳛـﺪﺙ ﻋﻨـﺪﻣﺎ‬ ‫ﺗﺘﻌﺪﻯ ﻗﻴﻤﺔ ﺇﺟﻬﺎﺩ ﺍﻟﺸﺪ ﺍﻟﻨﺎﲡﺔ ﻣﻦ ﺍﻟﺘﺤﻤﻴﻞ ﰱ ﺗﻠﻚ ﺍﳌﻨﻄﻘﺔ ﻗﻴﻤﺔ ﺃﻗﺼﻰ ﻣﻘﺎﻭﻣﺔ ﲤﺎﺳـﻚ ﻟﻠﻤﻌـﺪﻥ‬ ‫ﺍﳌﺨﺘﱪ‪ .‬ﻭﻳﻼﺣﻆ ﺃﻥ ﺣﺪﻭﺙ ﺍﻟﺮﻗﺒﺔ ﺑﺎﻟﻌﻴﻨﺔ ﻳﺘﺴﺒﺐ ﰱ ﺟﻌﻞ ﺗﻮﺯﻳﻊ ﺍﻹﺟﻬﺎﺩ ﻏﲑ ﻣﻨﺘﻈﻢ ﻋﻠﻰ ﺍﳌﻘﻄـﻊ‬ ‫ﺍﳌﺴﺘﻌﺮﺽ ﻋﻨﺪ ﺍﻟﺮﻗﺒﺔ ﻭﺫﻟﻚ ﺑﺈﺟﻬﺎﺩ ﻛﺒﲑ ﰱ ﻣﻨﻄﻘﺔ ﻭﺳﻂ ﺍﳌﻘﻄﻊ ﻭﻧﻘﻞ ﻗﻴﻤﺔ ﺍﻹﺟﻬﺎﺩ ﺗﺪﺭﳚﻴﺎ ﰱ ﺍﲡﺎﻩ‬ ‫ﺣﺮﻑ ﺍﳌﻘﻄﻊ ﻭﺗﻜﻮﻥ ﻗﻴﻤﺘﻪ ﻋﻨﺪ ﺍﳊﺮﻭﻑ ﺃﻗﻞ ﻣﻨﻬﺎ ﻛﺜﲑﹰﺍ ﻋﻦ ﻭﺳﻂ ﺍﳌﻘﻄﻊ ﻛﻤﺎ ﻳﺘﺒﲔ ﺫﻟﻚ ﻣﻦ ﺷﻜﻞ‬ ‫)‪ ،(٥-٢‬ﻟﺬﻟﻚ ﻳﻜﻮﻥ ﺍﺟﻬﺎﺩ ﺍﻟﺸﺪ ﰱ ﻣﻨﻄﻘﺔ ﺍﻟﻮﺳﻂ ﺃﻛﱪ ﻣﻦ ﻣﻘﺎﻭﻣﺔ ﲤﺎﺳﻚ ﺍﳌﻌﺪﻥ ﺍﻷﻣـﺮ ﺍﻟـﺬﻯ‬ ‫ﻳﺴﺒﺐ ﺍﻻ‪‬ﻴﺎﺭ ﺑﺎﻟﻜﺴﺮ ﺑﺎﻻﻧﻔﺼﺎﻝ ﺍﻟﻨﺎﺗﺞ ﻣﻦ ﺍﻟﺸﺪ‪.‬‬

‫ﺍﻻﺟﻬﺎﺩ ﺍﻟﻌﻤﻮﺩﻯ‬

‫‪σaverage‬‬

‫‪σmax‬‬

‫‘‪@ @†‘@kîšÓ@òjÓŠÛ@ô‰ìa@…bèu⁄a@Éí‹ìm@HUMRI@ÝØ‬‬

‫ﻭﻳﻼﺣﻆ ﺃﻳﻀﺎ ﺃﻥ ﺣﺪﻭﺙ ﺍﻟﺮﻗﺒﺔ ﺑﺎﻟﻌﻴﻨﺔ ﳚﻌﻞ ﺣﺎﻟﺔ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺑﺎﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻋﻨﺪ ﺍﻟﺮﻗﺒﺔ ﻋﺒـﺎﺭﺓ‬ ‫ﻋﻦ ﺇﺣﻬﺎﺩﺍﺕ ﰱ ﺍﻻﲡﺎﻫﺎﺕ ﺍﻟﺜﻼﺛﺔ ﻭﻟﻴﺴﺖ ﻛﻤﺎ ﻛﺎﻧﺖ ﻗﺒﻞ ﺣﺪﻭﺙ ﺍﻟﺮﻗﺒﺔ ﰱ ﺍﲡﺎﻩ ﳏﻮﺭﻯ ﻓﻘﻂ‪ ،‬ﻭﰱ‬ ‫ﻫﺬﻩ ﺍﳊﺎﻟﺔ ﻳﻜﻮﻥ ﺍﻹﺟﻬﺎﺩ ﺍﻟﻌﻤﻮﺩﻯ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﺍﻟﺬﻯ ﻳﻜﻮﻥ ﰱ ﺍﲡﺎﻩ ﺍﻟﺘﺤﻤﻴﻞ ﺍﶈـﻮﺭﻯ‬ ‫ﻋﻨﺪ ﻣﻨﻄﻘﺔ ﺍﳌﻨﺘﺼﻒ ﺃﻛﱪ ﺑﻜﺜﲑ ﻣﻦ ﻗﻴﻤﺔ ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﺍﻷﻓﻘﻰ ﻋﻨﺪ ﻫﺬﻩ ﺍﳌﻨﻄﻘﺔ ﻟﺬﻟﻚ ﻳﻜﻮﻥ ﺳـﺒﺐ‬ ‫ﺍﻟﻜﺴﺮ ﺑﺎﻻﻧﻔﺼﺎﻝ ﰱ ﻣﻨﻄﻘﺔ ﻭﺳﻂ ﺍﳌﻘﻄﻊ ﻫﻮ ﺇﺟﻬﺎﺩ ﺍﻟﺸﺪ ﺍﻟﻌﻤﻮﺩﻱ ﻭﻟﻴﺲ ﺇﺟﻬﺎﺩ ﻟﻘﺺ‪ ،‬ﻭﻳـﺼﺎﺣﺐ‬ ‫ﺫﻟﻚ ﺍﻻﻧﻔﺼﺎﻝ ﰱ ﺍﻟﻮﺳﻂ ﺍﺳﺘﻤﺮﺍﺭ ﺇﻧﺰﻻﻕ ﺟﺰﻳﺌﺎﺕ ﻣﻌﺪﻥ ﺍﻟﻌﻴﻨﺔ ﻋﻨﺪ ﻣﻨﻄﻘﺔ ﺣﺪﻭﺩ ﺍﳌﻘﻄﻊ‪.‬‬ ‫‪٣٥‬‬


‫(*() ‪Sliding‬‬

‫ﻭﺗﻠﻚ ﺍﳋﻄﻮﺓ ﺍﻟﺜﺎﻧﻴﺔ ﻭﺍﻟﱴ ﳛﺪﺙ ﻓﻴﻬﺎ ﺍﺳﺘﻤﺮﺍﺭ ﺇﻧﺰﻻﻕ ﺟﺰﻳﺌﺎﺕ ﺍﳌﻌﺪﻥ ﰱ ﻣﻨﻄﻘـﺔ ﺣـﺪﻭﺩ ﺍﳌﻘﻄـﻊ‬ ‫ﺍﳌﺴﺘﻌﺮﺽ ﻋﻨﺪ ﺍﻟﺮﻗﺒﺔ ﺑﻌﺪ ﺣﺪﻭﺙ ﺍﻻﻧﻔﺼﺎﻝ ﰱ ﻣﻨﻄﻘﺔ ﺍﻟﻮﺳﻂ ﺑﺈﺟﻬﺎﺩﺍﺕ ﺍﻟﺸﺪ ﻭﺍﻟﺬﻯ ﺑﺪﻭﺭﻩ ﻳﺆﺩﻯ‬ ‫ﻫﺬﺍ ﺍﻻﻧﺰﻻﻕ ﺇﱃ ﺍﻻ‪‬ﻴﺎﺭ ﺑﺎﻟﻜﺴﺮ ﻭﻳﻜﻮﻥ ﺫﻟﻚ ﻋﻠﻰ ﻣﺴﺘﻮﻯ ﻳﻌﻤﻞ ‪ ٤٥‬ﺩﺭﺟﺔ ﻣﻊ ﺍﳌﺴﺘﻮﻯ ﺍﻷﻓﻘـﻰ‬ ‫ﺃﻯ ﻋﻠﻰ ﺍﳌﺴﺘﻮﻯ ﺍﻟﺬﻯ ﻳﺆﺛﺮ ﻋﻠﻴﻪ ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﺍﻷﻗﺼﻰ ﻭﻳﻜﻮﻥ ﺍﻻﻧﻔﺼﺎﻝ ﻋﻠﻰ ﻫﺬﺍ ﺍﳌﺴﺘﻮﻯ ﻋﻠـﻰ‬ ‫ﺣﺮﻭﻑ ﺍﳌﻘﻄﻊ ﻧﺘﻴﺠﺔ ﻹﺟﻬﺎﺩ ﺍﻟﻘﺺ ﻭﻳﺴﻤﻰ ﺇﻧﻔﺼﺎﻝ ﺍﻟﻘﺺ‪ ،‬ﻭﻳﺴﻤﻰ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻻ‪‬ﻴﺎﺭ ﺑﺎﻟﻜﺴﺮ‬ ‫ﻟﻠﻤﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﺑﻜﺴﺮ ﺍﻟﻜﺄﺱ ﻭﺍﳌﺨﺮﻭﻁ )‪ (Cup and Cone failure‬ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑـﺸﻜﻞ‬ ‫)‪ ،(٦-٢‬ﻭﻳﻌﺘﱪ ﺷﻜﻞ ﻫﺬﺍ ﺍﻟﻜﺴﺮ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻣﻦ ﳑﻴﺰﺍﺕ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ‪ .‬ﻭﻳﻼﺣﻆ ﺃﻧﻪ ﻧﻈﺮﹰﺍ ﻷﻥ‬ ‫ﺍﻻﻧﻔﺼﺎﻝ ﺍﻟﻨﻬﺎﺋﻰ ﻟﻠﻤﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻋﻨﺪ ﺍﻟﺮﻗﺒﺔ ﺑﺴﺒﺐ ﺍﻻﻧﺰﻻﻕ ﻋﻠﻰ ﻣﺴﺘﻮﻳﺎﺕ ﻣﺎﺋﻠﺔ ‪ ٤٥‬ﺩﺭﺟﺔ ﺃﻯ‬ ‫ﻋﻠﻰ ﻣﺴﺘﻮﻳﺎﺕ ﻗﻮﻯ ﺍﻟﻘﺺ ﻓﻴﻤﻜﻦ ﺍﻋﺘﺒﺎﺭ ﺃﻥ ﺳﺒﺐ ﻛﺴﺮ ﺍﳌﻮﺍﺩ ﺍﳌﻄﻴﻠﺔ ﲢﺖ ﺗﺄﺛﲑ ﻗﻮﺓ ﺍﻟﺸﺪ ﻫﻮ ﺗﺄﺛﲑ‬ ‫ﺍﻟﻘﺺ‪ ،‬ﺃﻯ ﺃﻥ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﺗﻌﺘﱪ ﺿﻌﻴﻔﺔ ﰱ ﲢﻤﻞ ﺍﻟﻘﺺ ﻋﻨﻬﺎ ﰱ ﲢﻤﻠﻬﺎ ﻟﻠﺸﺪ‪.‬‬

‫‪Cup‬‬ ‫ﺍﻟﻜﺄﺱ‬

‫ﻣﺴﺘﻮﻯ ﺍﻧﻔﺼﺎﻝ ﺍﻟﺸﺪ‬ ‫ﺗﻮﺯﻳﻊ ﺍﻻﺟﻬﺎﺩﺍﺕ ﰱ‬

‫ﻣﺴﺘﻮﻯ ﺍﻧﺰﻻﻕ ﺍﻟﻘﺺ‬ ‫‪o٤٥‬‬

‫ﺍﳌﺨﺮﻭﻁ‬ ‫‪Cone‬‬

‫ﻣﻨﻄﻘﺔ ﺍﻟﺮﻗﺒﺔ‬

‫‘‪@ @†’Ûa@óÏ@òÜîĐ½a@æ…bÈ½a@‰bîèãa@HVMRI@ÝØ‬‬

‫‪@ @òÐ–ÔÛa@òîã†È½a@…aì½a@ÚìÜ@òa‰…@RMRMR‬‬ ‫ﻋﻨﺪ ﲢﻤﻴﻞ ﻋﻴﻨﺔ ﻣﻦ ﺍﳌﻌﺎﺩﻥ ﺍﻟﻘﺼﻔﺔ ﲝﻤﻞ ﺷﺪ ﻳﺰﺩﺍﺩ ﺗﺪﺭﳚﻴﺎ ﻓﺈﻥ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﳊﺎﺩﺛﺔ ﻣـﻦ‬ ‫ﻫﺬﺍ ﺍﳊﻤﻞ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ ،(٧-٢‬ﺣﻴﺚ ﺗﻼﺣﻆ ‪‬ﺬﺍ ﺍﳌﻨﺤﲎ ﻋـﺪﻡ ﺗﻮﺍﺟـﺪ ﺃﻯ ﻓﺘـﺮﺍﺕ‬ ‫ﺗﻨﺎﺳﺐ ﺑﲔ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﻛﻤﺎ ﻻ ﺗﻮﺟﺪ ﺃﻯ ﻣﻨﻄﻘﺔ ﻟﻠﺨﻀﻮﻉ ﻛﻤﺎ ﺃﻥ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﳊﺎﺩﺛﺔ ﻣﻦ ﺍﳊﻤـﻞ‬ ‫ﺻﻐﲑﺓ ﺟﺪﹰﺍ ﺇﺫﺍ ﻣﺎ ﻗﻮﺭﻧﺖ ﺑﺎﺳﺘﻄﺎﻟﺔ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ‪.‬ﻛﻤﺎ ﻧﻼﺣﻆ ﺃﻳﻀﺎ ﻋﺪﻡ ﺣﺪﻭﺙ ﺭﻗﺒﺔ ﺑﺎﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ‬ ‫ﻭﺃﻥ ﺍﻟﻜﺴﺮ ﳛﺪﺙ ﻋﻠﻰ ﻫﻴﺌﺔ ﻣﺴﺘﻮﻯ ﻋﻤﻮﺩﻯ ﻋﻠﻰ ﺍﲡﺎﻩ ﺍﻟﺘﺤﻤﻴﻞ ﻭﻫﺬﺍ ﻳﻌﲎ ﺃﻥ ﺍﻟﻜﺴﺮ ﳛﺪﺙ ﺑـﺴﺒﺐ‬ ‫ﺇﻧﻔﺼﺎﻝ ﺍﻟﺸﺪ ﻓﻘﻂ‪ ،‬ﺃﻯ ﺃﻥ ﺍﳌﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﺗﻜﺴﺮ ﰱ ﺍﻟﺸﺪ ﲢﺖ ﺗﺄﺛﲑ ﺇﺟﻬﺎﺩ ﺍﻟﺸﺪ ﻓﻘﻂ‪ ،‬ﻭﻟﺬﻟﻚ ﺗﻌﺘـﱪ‬ ‫ﻫﺬﻩ ﺍﳌﻮﺍﺩ ﺿﻌﻴﻔﺔ ﰱ ﲢﻤﻞ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﺸﺪ ﻋﻨﻬﺎ ﰱ ﲢﻤﻞ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﺺ‪٠‬‬ ‫‪٣٦‬‬


‫ﺍﳊﻤﻞ‬

‫ﲪﻞ ﺍﻟﻜﺴﺮ‬

‫ا دة ‬

‫ا دة ‬

‫ﺃﻗﺼﻰ ﲪﻞ‬


‫‘‪@ @Ñ–Ó@æ†È½@òÛbĐnüaë@Ýà§a@óäzäß@HWMRI@ÝØ‬‬ ‫@@‬

‫‪@ @òÜîĐ½a@Ñ–ã@òîã†È½a@…aì½a@ÚìÜ@òa‰…@SMRMR‬‬ ‫ﺇﺫﺍ ﺗﻌﺮﺽ ﻗﻀﻴﺐ ﻣﻦ ﻣﻌﺪﻥ ﻧﺼﻒ ﻣﻄﻴﻞ ﻣﺜﻞ ﺍﻟﺼﻠﺐ ﻋﺎﱃ ﺍﳌﻘﺎﻭﻣﺔ ﺇﱃ ﲪﻞ ﺷﺪ ﻳـﺰﺩﺍﺩ ﺗـﺪﺭﳚﻰ ﰒ‬ ‫ﺗﻘﺎﺱ ﻗﻴﻤﺔ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﳌﻘﺎﺑﻠﺔ ﻟﻜﻞ ﲪﻞ ﻭﻳﺮﺳﻢ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﻛﻤﺎ ﻫﻮ ﻣﺒﲔ ﺑﺸﻜﻞ )‪(٨-٢‬‬ ‫ﻭﻫﺬﺍ ﺍﳌﻨﺤﲎ ﻟﻪ ﻧﻔﺲ ﺍﻟﺸﻜﻞ ﺍﻟﻌﺎﻡ ﳌﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﻟﻠﻤﻌﺪﻥ ﺍﳌﻄﻴﻞ ﲢﺖ ﺗﺄﺛﲑ ﺃﲪـﺎﻝ ﻭﻟﻜـﻦ‬ ‫ﻳﻼﺣﻆ ﻋﺪﻡ ﻭﺟﻮﺩ ﻣﻨﻄﻘﺔ ﺧﻀﻮﻉ ﻛﻤﺎ ﺃﻥ ﺍﳊﻤﻞ ﺃﻛﺜﺮ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﺃﻗﻞ ﻣﻦ ﻣﺜﻴﻼ‪‬ﺎ ﻣﻦ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ‪.‬‬ ‫ﻭﻳﻜﻮﻥ ﺷﻜﻞ ﺍﻟﻜﺴﺮ ﻋﻠﻰ ﻫﻴﺌﺔ ﻗﺪﺡ ﻭﳐﺮﻭﻁ ﺃﻳﻀﺎ ﻭﻟﻜﻦ ﺑﺮﻗﺒﺔ ﺃﻗﻞ ﻭﺿﻮﺣﹰﺎ ﻣﻨﻬﺎ ﰱ ﺍﳌﻌﺪﻥ ﺍﳌﻄﻴﻞ‪.‬‬

‫ﺍﳊﻤﻞ‬


‫‘‪@ @ÝîĐß@Ñ–ã@æ†È½@òÛbĐnüaë@Ýà§a@óäzäß@HXMRI@ÝØ‬‬

‫‪٣٧‬‬


‫‪@ @@†’Ûa@óÏ@òÐÜn‚½a@æ…bÈ½a@Š×@püby@í@òã‰bÔ½a@TMRMR‬‬ ‫ﻳﻜﻮﻥ ﻛﺴﺮ ﺍﳌﻌﺎﺩﻥ ﻋﻤﻮﻣﺎ ﲢﺖ ﺗﺄﺛﲑ ﺃﲪﺎﻝ ﺍﻟﺸﺪ ﻧﺘﻴﺠﺔ ﺍﻻﻧﻔﺼﺎﻝ ﺑﺎﺟﻬﺎﺩﺍﺕ ﺍﻟـﺸﺪ ﺃﻭ ﺍﻻﻧـﺰﻻﻕ‬ ‫ﺑﺎﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﺺ ﺃﻭ ﻛﻠﻴﻬﻤﺎ ﻭﺫﻟﻚ ﻋﻨﺪ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﺍﻟﺬﻯ ﳛﺘﻮﻯ ﻋﻠﻰ ﺍﻟﺮﻗﺒﺔ ﺍﻯ ﺃﻥ ﺍﻟﻜـﺴﺮ‬ ‫ﺑﻘﻮﺓ ﺍﻟﺸﺪ ﻳﻨﺘﺞ ﻣﻦ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﺸﺪ ﺍﻟﱴ ﲢﺪﺙ ﺍﻻﻧﻔﺼﺎﻝ ﺃﻭﻣﻦ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﺺ ﺍﻟﱴ ﲢﺪﺙ ﺍﻻﻧﺰﻻﻕ‬ ‫ﻛﻤﺎ ﻳﺘﺒﲔ ﺫﻟﻚ ﻣﻦ ﺍﻟﺸﻜﻞ )‪.(٩-٢‬‬ ‫‪P‬‬

‫‪P‬‬

‫‪P‬‬

‫‪P‬‬

‫‪f = P/A‬‬ ‫‪f‬‬

‫‪q‬‬

‫‪f‬‬

‫‪q‬‬

‫‪f = q = P/2A‬‬

‫‪P‬‬

‫‘‪@ @†’Ûa@pbäîÈi@ŠØÛa@ÝØ‘@HYMRI@ÝØ‬‬

‫ﻓﺈﺫﺍ ﻛﺎﻧﺖ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﻟﻼﻧﺰﻻﻕ ﻋﺎﻟﻴﺔ ﻓﺈﻧﻪ ﻳﻨﻜﺴﺮ ﺑﺎﻻﻧﻔﺼﺎﻝ ﻋﻨﺪﻣﺎ ﻳﺰﻳﺪ ﺇﺟﻬﺎﺩ ﺍﻟﺸﺪ ﻋﻦ ﻣﻘﺎﻭﻣﺔ‬ ‫ﲤﺎﺳﻚ ﺟﺰﻳﺌﺎﺕ ﺍﳌﻌﺪﻥ ‪ ،‬ﻭﻳﻜﻮﻥ ﺫﻟﻚ ﻏﺎﻟﺒﺎ ﻣﺼﺤﻮﺑﹰﺎ ﺑﺎﺳﺘﻄﺎﻟﺔ ﺻﻐﲑﺓ ﺟﺪﺍﹰ‪ ،‬ﻭﻳﻌﺘﱪ ﺍﳌﻌﺪﻥ ﰱ ﻫـﺬﻩ‬ ‫ﺍﳊﺎﻟﺔ ﻗﺼﻔﺎﹰ‪ ،‬ﻭﻳﻜﻮﻥ ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ ﻋﻤﻮﺩﻳﺎ ﻋﻠﻰ ﺍﲡﺎﻩ ﲪﻞ ﺍﻟﺸﺪ ﺍﳌﺆﺛﺮ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘـﱪﺓ ﻣﺜـﻞ‬ ‫ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ ‪.‬‬ ‫ﺃﻣﺎ ﺇﺫﺍ ﻛﺎﻧﺖ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﻟﻼﻧﻔﺼﺎﻝ ﻛﺒﲑﺓ ﻓﺈﻧﻪ ﻳﻨﻜﺴﺮ ﺑﺎﻻﻧﺰﻻﻕ ﺑﻔﻌﻞ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﺺ ﻭﻳﻜـﻮﻥ‬ ‫ﻣﺼﺤﻮﺑﺎ ﺑﺎﺳﺘﻄﺎﻟﺔ ﻛﺒﲑﺓ ﻭﻧﻘﺺ ﻇﺎﻫﺮ ﰱ ﻋﺮﺽ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﺃﻯ ﺣﺪﻭﺙ ﺭﻗﺒﺔ ﻗﺒـﻞ ﺣـﺪﻭﺙ‬ ‫ﺍﻟﻜﺴﺮ‪ .‬ﻭﻳﻌﺘﱪ ﺍﳌﻌﺪﻥ ﰱ ﻫﺬﻩ ﺍﳊﺎﻟﺔ ﻣﻄﻴﻼ ﻭﻳﻜﻮﻥ ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ ﻋﻠﻰ ﺯﺍﻭﻳﺔ ‪ ٤٥‬ﺩﺭﺟﺔ ﻣﻊ ﺍﶈـﻮﺭ‬ ‫ﺍﻟﻄﻮﱃ ﻟﻠﻌﻴﻨﺔ ﻭﻳﻜﻮﻥ ﺫﻟﻚ ﻣﺼﺤﻮﺑﺎ ﰱ ﻣﻌﻈﻢ ﺍﳊﺎﻻﺕ ﺑﺈﻧﻔﺼﺎﻝ ﻋﻠﻰ ﺑﺎﻗﻰ ﺍﳌﻘﻄﻊ ﻭﻳﻜـﻮﻥ ﺷـﻜﻞ‬ ‫ﺍﻟﻜﺴﺮ ﻋﻠﻰ ﻫﻴﺌﺔ ﻛﺄﺱ ﻭﳐﺮﻭﻁ ﻭﻣﻦ ﻫﺬﻩ ﺍﳌﻮﺍﺩ ﺍﳌﻄﻴﻠﺔ ﺍﻟﺼﻠﺐ ﺍﻟﻄﺮﻯ‪ .‬ﻭﺇﺫﺍ ﻛﺎﻧﺖ ﺣﺎﻟـﺔ ﺍﳌﻌـﺪﻥ‬ ‫ﻣﺘﻘﺎﺭﺑﺔ ﺑﲔ ﻣﻘﺎﻭﻣﺘﻪ ﻟﻼﻧﻔﺼﺎﻝ ﻭﻣﻘﺎﻭﻣﺘﻪ ﻟﻼﻧﺰﻻﻕ ﻓﺈﻥ ﺍﳌﻌﺪﻥ ﻳﻜﺴﺮ ﺃﻭﻻ ﺑﺴﺒﺐ ﺍﳌﻘﺎﻭﻣـﺔ ﺍﻷﻗـﻞ ﰒ‬ ‫ﻳﻜﻤﻞ ﺍﻟﻜﺴﺮ ﺑﺎﳌﻘﺎﻭﻣﺔ ﺍﻷﻛﱪ ﻧﺴﺒﻴﺎ ﻭﻳﻜﻮﻥ ﺍﻟﻜﺴﺮ ﻋﻠﻰ ﻫﻴﺌﺔ ﺍﻟﻜﺄﺱ ﻭﺍﳌﺨﺮﻭﻁ ﺍﻟﻐﲑ ﻇﺎﻫﺮ ﻧـﺴﺒﻴﺎ‬ ‫ﻛﻤﺎ ﻫﻮ ﺍﳊﺎﻝ ﰱ ﺍﳌﻌﺎﺩﻥ ﺍﻟﻨﺼﻒ ﻣﻄﻴﻠﺔ ﻣﺜﻞ ﺍﻟﺼﻠﺐ ﻋﺎﱃ ﺍﻟﻜﺮﺑـﻮﻥ‪ .‬ﺍﻟـﺸﻜﻞ )‪ (١٠-٢‬ﻳﻮﺿـﺢ‬ ‫ﻣﻘﺎﺭﻧﺔ ﺑﲔ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﻭﻧﺼﻒ ﺍﳌﻄﻴﻠﺔ ﻭﺍﻟﻘﺼﻔﺔ ﲢﺖ ﺗﺄﺛﲑ ﲪﻞ ﺍﻟﺸﺪ ﺣﱴ ﺍﻟﻜﺴﺮ ﻭﺫﻟﻚ ﻋﻠﻰ ﻧﻔﺲ‬ ‫ﻣﻘﻴﺎﺱ ﺍﻟﺮﺳﻢ‪٠‬‬ ‫‪٣٨‬‬


‫ﻣﺎﺩﺓ ﻣﻄﻴﻠﺔ ﻣﺜﻞ ﺍﻟﺼﻠﺐ ﺍﻟﻄﺮﻱ‬

‫ﺍﳊﻤﻞ ‪Load‬‬

‫ﻣﺎﺩﺓ ﻧﺼﻒ ﻣﻄﻴﻠﺔ ﻣﺜﻞ ﺍﻟﺼﻠﺐ ﻋﺎﱄ ﺍﳌﻘﺎﻭﻣﺔ‬ ‫)‪Semi-Ductile Material (High Tensile Steel‬‬

‫)‪Ductile Material (Mild Steel‬‬

‫ﻣﺎﺩﺓ ﻗﺼﻔﺔ ﻣﺜﻞ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ‬ ‫)‪Brittle Material (Cast Iron‬‬

‫ﺍﻻﺳﺘﻄﺎﻟﺔ ‪Elongation‬‬ ‫@@‬ ‫@@‬ ‫‘‪@ @òÐ–ÔÛaë@òÜîĐ½a@Ñ–ãë@òÜîĐ½a@æ…bÈàÜÛ@òÛbĐnüaë@Ýà§a@óäzäß@HQPMRI@ÝØ‬‬

‫ﻭﳝﻜﻦ ﺗﻘﺴﻴﻢ ﺃﻧﻮﺍﻉ ﺍﻟﻜﺴﻮﺭ ﺍﻟﻨﺎﲡﺔ ﻟﻠﻤﻌﺎﺩﻥ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻭﺫﻟﻚ ﺑﺎﻟﻨﺴﺒﺔ‪:‬‬ ‫•‬

‫ﻟﻠﺸﻜﻞ‬

‫•‬

‫ﺣﺎﻟﺔ ﺍﻟﺴﻄﺢ )‪(Texture‬‬

‫•‬

‫ﺍﻟﻠﻮﻥ )‪(Color‬‬

‫)‪(Form‬‬

‫ﻭﳝﻜﻦ ﺍﻟﺘﻌﺮﻑ ﺑﺪﻗﺔ ﻋﻠﻰ ﻧﻮﻉ ﻣﻌﻈﻢ ﺍﳌﻌﺎﺩﻥ ﰱ ﺣﺎﻟﺔ ﻛﺴﺮﻫﺎ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻓﻤﺜﻼ ﺍﻟﺼﻠﺐ ﺍﻟﻄـﺮﻯ‬ ‫ﻳﻜﻮﻥ ﺷﻜﻞ ﺍﻟﻜﺴﺮ ﻋﻠﻰ ﻫﻴﺌﺔ ﻛﺄﺱ ﻭﳐﺮﻭﻁ‪ ،‬ﻭﻳﻜﻮﻥ ﺍﻟﺴﻄﺢ ﺧﺸﻨﺎ ﰱ ﻣﻨﺘﺼﻒ ﺍﳌﻘﻄﻊ ﺍﳌـﺴﺘﻌﺮﺽ‬ ‫ﻭﻳﻜﻮﻥ ﻟﻪ ﻣﻠﻤﺲ ﻧﺎﻋﻢ ﻋﻨﺪ ﺍﳊﺮﻭﻑ‪ ،‬ﻭﻳﻜﻮﻥ ﻟﻮﻥ ﺍﻟﻜﺴﺮ ﻋﻨﺪ ﺍﻟﺴﻄﺢ ﺍﳋﺸﻦ ﰱ ﺍﳌﻨﺘﺼﻒ ﺩﺍﻛـﻦ‬ ‫ﻭﻋﻨﺪ ﺍﻷﻃﺮﺍﻑ ﻻﻣﻊ‪ .‬ﺃﻣﺎ ﺍﻟﻜﺴﺮ ﰱ ﺍﳊﺪﻳﺪ ﺍﳌﻄﺎﻭﻉ ﻳﻜﻮﻥ ﻟﻴﻔﻰ ﻣﺘﻘﻄﻊ ﺑﻴﻨﻤﺎ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ ﻳﻜـﻮﻥ‬ ‫ﻣﺴﻄﺤﺎ ﻭﳏﺒﺒﹰﺎ‪ .‬ﻭﻳﻼﺣﻆ ﺃﻳﻀﺎ ﺃﻧﻪ ﳝﻜﻦ ﻣﻦ ﻓﺤﺺ ﺍﻟﻜﺴﺮ ﺍﻟﺘﻮﺻﻞ ﺇﱃ ﻣﻌﺮﻓﺔ ﺿﻌﻒ ﺍﻟﻌﻴﻨﺎﺕ ﺍﳌﺨﺘﱪﺓ‬ ‫ﻣﻦ ﻭﺟﻬﺔ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻭﺍﳌﻤﻄﻮﻟﻴﺔ ﻛﻤﺎ ﺃﻥ ﺍﻟﺘﺤﻤﻴﻞ ﺍﻟﻐﲑ ﳏﻮﺭﻯ ﻳﺴﺒﺐ ﻛﺴﺮﹰﺍ ﻏﲑ ﻣﺘﻤﺎﺛﻞ ﳛـﺪﺙ‬ ‫ﻣﻦ ﻋﺪﻡ ﲡﺎﻧﺲ ﺍﳌﺎﺩﺓ ﺃﻭ ﺗﻮﺍﺟﺪ ﺑﻌﺾ ﺍﻟﻌﻴﻮﺏ ‪‬ﺎ ﻣﺜﻞ ﺍﻻﻧﻔﺼﺎﻝ ﺃﻭ ﺍﻟﻔﺠﻮﺍﺕ ﺃﻭ ﺍﻟﺸﻮﺍﺋﺐ‪ .‬ﺃﻣـﺎ ﰱ‬ ‫ﺣﺎﻟﺔ ﺍﳌﻌﺎﺩﻥ ﺍﻟﱴ ﺗﻌﺮﺿﺖ ﺇﱃ ﺍﻟﺘﺸﻐﻴﻞ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﺃﻭ ﺍﻟﱴ ‪‬ﺎ ﺍﺟﻬﺎﺩﺍﺕ ﺩﺍﺧﻠﻴﺔ ﳐﺘﻠﻔـﺔ ﻳﻼﺣـﻆ ﺃﻥ‬ ‫ﺍﻟﻜﺴﺮ ﻓﻴﻬﺎ ﻳﻈﻬﺮ ﻏﺎﻟﺒﺎ ﺑﺴﻄﺤﻪ ﻋﻼﻣﺎﺕ ﺧﻄﻴﺔ ﺃﻭ ﺣﺮﻭﻑ ﺗﺘﻼﻗﻰ ﰱ ﻧﻘﻄﺔ ﻋﻨـﺪ ﻣﻨﺘـﺼﻒ ﺍﳌﻘﻄـﻊ‬ ‫ﺍﳌﺴﺘﻌﺮﺽ ﻭﺗﺘﺠﻪ ﻗﻄﺮﻳﹰﺎ ﺇﱃ ﺣﺮﻭﻑ ﺍﳌﻘﻄﻊ ﻭﻳﺴﻤﻰ ﺑﺎﻟﻜﺴﺮ ﺍﻟﻨﺠﻤﻰ‪ ،‬ﻭﻣﻦ ﻫﻨﺎ ﳝﻜﻦ ﺍﻟﺘﻌﺮﻑ ﻋﻠـﻰ‬ ‫ﺃﻧﻮﺍﻉ ﺍﳌﻌﺎﺩﻥ ﻣﻦ ﺷﻜﻞ ﺣﺎﻻﺕ ﺍﻟﻜﺴﺮ ﲢﺖ ﺗﺄﺛﲑ ﺃﲪﺎﻝ ﺍﻟﺸﺪ ﻋﻠﻰ ﺿﻮﺀ ﻣﺎ ﺳﺒﻖ‪.‬‬ ‫‪٣٩‬‬


‫‪ # ,- ./ 3-2‬‬

‫ﻟﻠﺨﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﺃﳘﻴﺔ ﺧﺎﺻﺔ ﰱ ﲢﺪﻳﺪ ﺗﻌﻴﲔ ﺳﻠﻮﻙ ﺍﳌﻮﺍﺩ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻟﻠﻤﻌﺎﺩﻥ ﻭﻳﺘﻢ ﺗﻔـﺴﲑ‬ ‫ﺃﻫﻢ ﻫﺬﻩ ﺍﳋﻮﺍﺹ ﻓﻴﻤﺎ ﻳﻠﻰ‪:‬‬ ‫‪@ @Proportional Limit@@kbänÛa@†y@…bèug@QMSMR‬‬ ‫ﺇﺟﻬﺎﺩ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻫﻮ ﻗﻴﻤﺔ ﺃﻛﱪ ﺇﺟﻬﺎﺩ ﻳﻜﻮﻥ ﻋﻨﺪﻩ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻣﺘﻨﺎﺳﺒﲔ ﺃﻭ ﻫﻮ ﺍﻹﺟﻬـﺎﺩ‬ ‫ﺍﻟﺬﻯ ﻳﺘﻮﻗﻒ ﻋﻨﺪﻩ ﺍﻟﺘﻨﺎﺳﺐ ﺑﲔ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ‪ ،‬ﻭﺗﺘﻮﻗﻒ ﺩﻗﺔ ﲢﺪﻳﺪ ﻫﺬﺍ ﺍﻹﺟﻬﺎﺩ ﻋﻠـﻰ ﻣـﺪﻯ‬ ‫ﺣﺴﺎﺳﻴﺔ ﺃﺟﻬﺰﺓ ﺍﻟﻘﻴﺎﺱ ﻭﻳﻌﲔ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻋﻤﻠﻴﹰﺎ ﺑﺮﺳﻢ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﻭﲢﺪﻳﺪ ﺍﻹﺟﻬـﺎﺩ‬ ‫ﺍﻟﺬﻯ ﻳﺘﻮﻗﻒ ﻋﻨﺪﻩ ﺍﳋﻂ ﺍﳌﺴﺘﻘﻴﻢ ﻣﻦ ﺍﳌﻨﺤﲎ‪ .‬ﻭﻟﺬﻟﻚ ﻓﺈﻥ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻻ ﳝﻜـﻦ ﺍﻋﺘﺒـﺎﺭﻩ ﺣـﺪﹰﺍ‬ ‫ﻟﻠﻤﺮﻭﻧﺔ ﻭﻻ ﻳﺘﺨﺬ ﺃﺳﺎﺳﹰﺎ ﻟﻠﺘﺼﻤﻴﻢ ﰱ ﻣﻨﻄﻘﺔ ﺍﳌﺮﻭﻧﺔ ﻷﻥ ﺗﻌﻴﲔ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻣـﻦ ﻣـﻨﺤﲎ ﺍﳊﻤـﻞ‬ ‫ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﻟﻴﺲ ﻋﻠﻰ ﺩﺭﺟﺔ ﺩﻗﻴﻘﺔ ﻣﻦ ﺍﻟﺼﺤﺔ ﺑﺴﺒﺐ ﺍﺧﺘﻼﻑ ﻛﻴﻔﻴﺔ ﻭﻃﺮﻳﻘﺔ ﺗﻮﻗﻴﻊ ﺍﻟﺮﺳﻢ ﺍﻟﺒﻴـﺎﱏ‬ ‫ﻟﻠﻤﻨﺤﲎ ﺍﳌﻄﻠﻮﺏ ﻛﻤﺎ ﻫﻮ ﻣﺒﲔ ﺑﺎﻟﺸﻜﻞ )‪.(١١-٢‬‬ ‫‪Elastic Limit@@òãëŠ½a@†y@…bèug@RMSMR‬‬

‫ﺇﺟﻬﺎﺩ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﻫﻮ ﺃﻛﱪ ﺇﺟﻬﺎﺩ ﺗﺘﺤﻤﻠﻪ ﺍﳌﺎﺩﺓ ﺑﺸﺮﻁ ﻋﺪﻡ ﺑﻘﺎﺀ ﺃﻯ ﺍﺳﺘﻄﺎﻟﺔ ﺩﺍﺋﻤﺔ ﺑﻌﺪ ﺯﻭﺍﻝ ﻫـﺬﺍ‬ ‫ﺍﻹﺟﻬﺎﺩ‪ .‬ﻭﻗﺪ ﺍﻓﺘﺮﺽ ﺃﻧﻪ ﳝﻜﻦ ﺍﻟﻮﺻﻮﻝ ﺇﱃ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﺇﺫﺍ ﻛﺎﻧﺖ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﻟﺪﺍﺋﻤـﺔ ﺑﻌـﺪ ﺯﻭﺍﻝ‬ ‫ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﺻﻐﲑﺓ ﺟﺪﹰﺍ ﺗﺴﺎﻭﻯ ‪ %٠,٠١‬ﻣﻦ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻟﺘﻜﻮﻥ ﺍﳊﺪ ﺑـﲔ ﺭﺟـﻮﻉ ﺍﳌـﺎﺩﺓ ﺇﱃ‬ ‫ﺃﺑﻌﺎﺩﻫﺎ ﺍﻷﺻﻠﻴﺔ ﺑﻌﺪ ﺯﻭﺍﻝ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻭﺑﲔ ﻋﺪﻡ ﺭﺟﻮﻋﻬﺎ ﲤﺎﻣﹰﺎ‪ .‬ﻭﻳﻼﺣﻆ ﰱ ﺑﻌﺾ ﺍﳌﻌـﺎﺩﻥ ﻣﺜـﻞ‬ ‫ﺍﻟﺼﻠﺐ ﻣﻨﺨﻔﺾ ﻭﻣﺘﻮﺳﻂ ﺍﻟﻜﺮﺑﻮﻥ ﺃﻥ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﻳﻨﻄﺒﻖ ﲤﺎﻣﺎ ﻋﻠﻰ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻭﻫﺬﻩ ﻟﻴﺴﺖ ﻗﺎﻋﺪﺓ‬ ‫ﻋﺎﻣﺔ ﺣﻴﺚ ﺃﻥ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﻟﻪ ﻗﻴﻤﺔ ﺃﻋﻠﻰ ﻗﻠﻴﻼ ﻣﻦ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻛﻤﺎ ﻳﺘﻀﺢ ﻣﻦ ﺍﻟـﺸﻜﻞ)‪.(١١-٢‬‬ ‫ﻭﻋﻠﻰ ﺫﻟﻚ ﻓﺄﺣﻴﺎﻧﺎ ﻳﻌﺘﱪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻫﻮ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﻣﻊ ﺇﳘﺎﻝ ﺍﻟﻔﺮﻕ ﺍﻟﺼﻐﲑ ﺑﻴﻨﻬﻤﺎ ﻭﺫﻟـﻚ ﻣـﻦ‬ ‫ﺍﻟﻮﺟﻬﺔ ﺍﻟﻌﻤﻠﻴﺔ‪ .‬ﻭﳝﻜﻦ ﺗﻌﻴﲔ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﺍﳌﻌﺘﱪ ﺣﺪﹰﺍ ﻟﻠﻤﺮﻭﻧﺔ ﺑﻄﺮﻳﻘﺔ "ﺟﻮﻧﺴﻮﻥ" ﻛﻤﺎ ﻳﺘـﺒﲔ ﻣـﻦ‬ ‫ﺍﻟﺸﻜﻞ )‪ (١٢-٢‬ﺣﻴﺚ ﻳﻌﺘﱪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻫﻮ ﺍﻹﺟﻬﺎﺩ ﺍﻟﺬﻯ ﻳﻘﺎﺑﻞ ﻧﻘﻄﺔ ﻋﻠـﻰ ﺍﳌـﻨﺤﲎ ﻟﻠﺤﻤـﻞ‬ ‫ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﻳﻜﻮﻥ ﻋﻨﺪﻫﺎ ﻣﻌﺪﻝ ﺍﻻﺳﺘﻄﺎﻟﺔ ‪ %٥٠‬ﺍﻛﱪ ﻣﻦ ﻣﻌﺪﻝ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻋﻨﺪ ﺑﺪﺍﻳـﺔ ﺍﻟﺘﺤﻤﻴـﻞ‬ ‫ﻭﻫﺬﻩ ﺍﻟﻨﻘﻄﺔ ﺗﻌﲔ ﺍﳊﻤﻞ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻭﻣﻨﻬﺎ ﺗﻌﻴﲔ ﺇﺟﻬﺎﺩ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﺑﻘﺴﻤﺔ ﺍﳊﻤـﻞ ﻋﻠـﻰ‬ ‫ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﻷﺻﻴﻠﺔ ﻟﻠﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ‪.‬‬ ‫‪٤٠‬‬


‫ﺍﳊﻤﻞ‬ ‫إ&‪%‬د ا‪"#$‬ع ا ( ‪Upper Yield‬‬

‫إ&‪%‬د ا‪"#$‬ع ا د ‪Lower Yield‬‬ ‫ او ‪Elastic Limit‬‬ ‫ ا ‪Proportional‬‬


‫‘‪@ @ÝîĐß@æ†È½@ÞbÈÐãüaë@…bèu⁄a@óäzä½@Êìšäë@òãëŠ½a@òÔĐäß@HQQMRI@ÝØ‬‬

‫ﳝﺜﻞ ﺷﻜﻞ )‪ (١٢-٢‬ﺍﳌﻨﺤﲎ )‪ (O–A–B‬ﻭﻫﻮ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻻﺧﺘﺒﺎﺭ ﺍﻟـﺸﺪ ﻭﻋﻨـﺪ‬ ‫ﺍﳌﺮﺣﻠﺔ ﺍﻷﻭﱃ ﻣﻦ ﺍﻟﺘﺤﻤﻴﻞ ﻭﺍﳌﻤﺜﻠﺔ ﺑﺎﳉﺰﺀ )‪ (O-A‬ﻭﻫﺬﺍ ﻫﻮ ﺍﳉﺰﺀ ﺍﳌﺴﺘﻘﻴﻢ ﻣﻦ ﺍﳌﻨﺤﲎ‪ ،‬ﻭﻟﺘﻌﻴﲔ ﺣﺪ‬ ‫ﺍﻟﺘﻨﺎﺳﺐ ﻳﺮﺳﻢ ﺍﳋﻂ )‪ (O-D‬ﻟﻪ ﻣﻴﻞ ‪ %٥٠‬ﺃﻛﱪ ﻣﻦ ﻣﻴﻞ ﺍﳋﻂ )‪ (O-E‬ﺃﻯ ﺃﻥ ﺍﳉﺰﺀ )‪(D-F‬‬

‫ﻳﺴﺎﻭﻯ ﻣﺮﺓ ﻭﻧﺼﻒ ﻣﻦ ﺍﳉﺰﺀ )‪ ،(F-E‬ﻓﺈﺫﺍ ﺭﺳﻢ ﳑﺎﺱ ﻟﻠﻤﻨﺤﲎ ﻭﻳﻮﺍﺯﻯ ﺍﳋﻂ )‪ (O-D‬ﻓﺈﻧﻪ ﻳﻘﻄﻌﺔ‬ ‫ﰱ ﻧﻘﻄﺔ )‪ ، (C‬ﻓﻴﻜﻮﻥ ﺍﺟﻬﺎﺩ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻋﻨﺪ ﻧﻘﻄﺔ ﺍﻟﺘﻤﺎﺱ )‪ (C‬ﻭﻳﻌﺘﱪ ﻫﻮ ﺇﺟﻬﺎﺩ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ‬ ‫ﺑﻄﺮﻳﻘﺔ ﺟﻮﻧﺴﻮﻥ‪.‬‬ ‫‪X‬‬

‫‪D‬‬ ‫‪E‬‬ ‫‪B‬‬

‫‪F‬‬


‫‪1.5X‬‬

‫\\ \\‬ ‫‪C‬‬ ‫‪A‬‬

‫ﺇﺟﻬﺎﺩ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ‬ ‫‪Proportional Limit‬‬

‫‪O‬‬

‫ﺍﻻﺳﺘﻄﺎﻟﺔ ‪Elongation‬‬

‫‘‪@ @BæìãìuB@òÔíŠĐi@kbänÛa@†y@´Èm@HQRMRI@ÝØ‬‬

‫‪٤١‬‬


‫‪Yield@@Êìšä@…bèug@SMSMR‬‬

‫ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﻫﻮ ﺍﻹﺟﻬﺎﺩ ﺍﻟﺬﻯ ﳛﺪﺙ ﻋﻨﺪﻩ ﺯﻳﺎﺩﺓ ﻣﻠﺤﻮﻇﺔ ﰱ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺑﺪﻭﻥ ﺯﻳﺎﺩﺓ ﰱ ﺍﳊﻤـﻞ‬ ‫ﺃﻯ ﺃﻥ ﺍﻻﻧﻔﻌﺎﻝ ﻳﺰﺩﺍﺩ ﺑﺪﻭﻥ ﺯﻳﺎﺩﺓ ﺍﻹﺟﻬﺎﺩ ﻭﻳﺘﺒﲔ ﻣﻦ ﺷﻜﻞ )‪ (١١-٢‬ﳌﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺃﻥ‬ ‫ﺍﻟﻨﻘﻄﺔ ﺍﻟﱴ ﲤﺜﻞ ﺑﺪﺍﻳﺔ ﺍﳋﻀﻮﻉ‪ ،‬ﺗﺴﻤﻰ ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﺍﻷﻋﻠﻰ ﻭﻫﻮ ﺃﻋﻠﻰ ﺇﺟﻬﺎﺩ ﰱ ﻣﻨﻄﻘﺔ ﺍﳋﻀﻮﻉ‪،‬‬ ‫ﻛﺬﻟﻚ ﳓﺼﻞ ﻋﻠﻰ ﺍﻟﻨﻘﻄﺔ ﺍﻟﱴ ﻳﻜﻮﻥ ﻋﻨﺪﻫﺎ ﺍﻹﺟﻬﺎﺩ ﺃﻗﻞ ﺇﺟﻬﺎﺩ ﰱ ﻣﻨﻄﻘﺔ ﺍﳋﻀﻮﻉ ﻭﻳﺴﻤﻰ ﺇﺟﻬـﺎﺩ‬ ‫ﺍﳋﻀﻮﻉ ﺍﻷﻭﻃﻰ ﻭﳛﺪﺙ ﻋﻨﺪﻫﺎ ﺗﻐﲑ ﻣﻠﺤﻮﻅ ﰱ ﺍﻻﺳﺘﻄﺎﻟﺔ‪ ،‬ﻭﻳﻼﺣﻆ ﺃﻥ ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﺍﻷﻋﻠﻰ ﻏﲑ‬ ‫ﺛﺎﺑﺖ ﺍﻟﻘﻴﻤﺔ ﻟﻠﻤﻌﺪﻥ ﺍﻟﻮﺍﺣﺪ ﻭﺇﳕﺎ ﻳﺘﻐﲑ ﻃﺒﻘﺎ ﻟﻈﺮﻭﻑ ﺍﻻﺧﺘﺒﺎﺭ ﻣﺜﻞ ﺳﺮﻋﺔ ﺍﻟﺘﺤﻤﻴﻞ ﻭﻏﲑﻫـﺎ‪ ،‬ﺃﻣـﺎ‬ ‫ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﺍﻷﻭﻃﻰ ﻗﻴﻤﺘﻪ ﺛﺎﺑﺘﺔ ﻟﻠﻤﻌﺪﻥ ﺍﻟﻮﺍﺣﺪ ﻟﺬﻟﻚ ﻳﻌﺘﱪ ﺧﺎﺻﻴﺘﻪ ﺃﺳﺎﺳـﻴﺔ ﻣـﻦ ﺧـﺼﺎﺋﺺ‬ ‫ﺍﳌﻌﺪﻥ‪ ،‬ﻭﻳﻄﻠﻖ ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﻟﻠﻤﻌﺪﻥ ﻋﻠﻰ ﻗﻴﻤﺔ ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﺍﻷﻭﻃﻰ‪.‬ﻭﳝﻜـﻦ ﺗﻌـﻴﲔ ﺇﺟﻬـﺎﺩ‬ ‫ﺍﳋﻀﻮﻉ ﺍﻷﻭﻃﻰ ﻣﻌﻤﻠﻴﺎ ﺑﺴﻬﻮﻟﺔ ﺃﺛﻨﺎﺀ ﺇﺟﺮﺍﺀ ﺍﻻﺧﺘﺒﺎﺭ ﺑﺎﻟﻄﺮﻕ ﺍﻵﺗﻴﺔ‪:‬‬ ‫‪ -١‬ﲪﻞ ﺍﳋﻀﻮﻉ ﻫﻮ ﺍﳊﻤﻞ ﺍﻟﺬﻯ ﻋﻨﺪﻩ ﻳﺴﻘﻂ ﺫﺭﺍﻉ ﺍﳌﺎﻛﻴﻨﺔ ﻋﻨﺪﻣﺎ ﳚﺮﻯ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻠﻰ ﻣﺎﻛﻴﻨﺔ ﻣـﻦ‬ ‫ﻧﻮﻉ ﺍﻟﺘﺮﺱ ﻭﺍﻟﻠﻮﻟﺐ ﺫﺍﺕ ﺍﻟﺬﺭﺍﻉ ﻭﺍﻟﺜﻘﻞ‪ ،‬ﻭﻋﺪﻡ ﺍﻟﺘﻤﻜﻦ ﻣﻦ ﺇﺟﺮﺍﺀ ﺍﻻﺗﺰﺍﻥ ﻣﻊ ﲪﻞ ﺍﻟﺸﺪ ﺍﳌﺆﺛﺮ‬ ‫ﺑﻪ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﻭﺫﻟﻚ ﻣﻦ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﳌﺴﺘﻤﺮﺓ ﺍﳌﻠﺤﻮﻇﺔ ﻋﻨﺪ ﺍﳋﻀﻮﻉ ﻣﻊ ﺛﺒﺎﺕ ﺍﳊﻤﻞ‪.‬‬ ‫‪ -٢‬ﻋﻨﺪﻣﺎ ﺗﻜﻮﻥ ﺍﳌﺎﻛﻴﻨﺎﺕ ﺍﳌﺴﺘﺨﺪﻣﺔ ﰱ ﺍﻻﺧﺘﺒﺎﺭ ﻣﻦ ﺍﻟﻨﻮﻉ ﺍﳍﻴﺪﺭﻭﻟﻴﻜﻲ ﺫﺍﺕ ﺍﻟﻘـﺮﺹ ﺍﳌـﺪﺭﺝ‬ ‫ﻭﺍﳌﺆﺷﺮ ﻣﻊ ﺍﻟﺒﻨﺪﻭﻝ ﻟﻘﻴﺎﺱ ﺍﳊﻤﻞ ﻓﺈﻥ ﲪﻞ ﺍﳋﻀﻮﻉ ﻫﻮ ﺍﳌﺼﺎﺣﺐ ﻟﺜﺒﻮﺕ ﺍﳌﺆﺷﺮ ﻣﻊ ﺍﻫﺘـﺰﺍﺯﺓ‬ ‫ﻗﻠﻴﻼ ﻭﻫﺬﺍ ﻣﻦ ﺛﺒﻮﺕ ﺍﳊﻤﻞ ﻋﻨﺪ ﺍﳋﻀﻮﻉ ﻭﺗﻐﲑﻩ ﻗﻠﻴﻼ ﺑﺎﻟﺰﻳﺎﺩﺓ ﺃﻭ ﺑﺎﻟﻨﻘﺼﺎﻥ ﻧﻈﺮﹰﺍ ﳊﺎﻟـﺔ ﻋـﺪﻡ‬ ‫ﺍﻻﺗﺰﺍﻥ ﻋﻨﺪ ﺍﳋﻀﻮﻉ ﻭﻳﻜﻮﻥ ﲪﻞ ﺍﳋﻀﻮﻉ ﻫﻮ ﺃﻗﻞ ﻗﺮﺍﺀﺓ ﻳﺴﺠﻠﻬﺎ ﺍﳌﺆﺷﺮ ﻋﻨﺪ ﺛﺒﺎﺗﻪ‪.‬‬ ‫‪ -٣‬ﻋﻨﺪﻣﺎ ﻳﻼﺣﻆ ﺗﻐﲑ ﻓﺠﺎﺋﻰ ﻣﻠﺤﻮﻅ ﻭﺍﺿﺢ ﰱ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻓﻴﻜﻮﻥ ﺫﻟﻚ ﺩﻻﻟﺔ ﻋﻠـﻰ ﺣـﺪﻭﺙ‬ ‫ﺧﻀﻮﻉ ﻭﺃﻥ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﻋﻨﺪ ﻫﺬﺍ ﺍﻟﺘﻐﲑ ﻫﻮ ﲪﻞ ﺍﳋﻀﻮﻉ ﺍﻷﻭﻃﻰ ﺍﳌﻄﻠﻮﺏ‪.‬‬ ‫‪ -٤‬ﺗﻼﺣﻆ ﺗﺴﺎﻗﻂ ﺍﻟﻘﺸﺮﺓ ﺍﻟﺴﻄﺤﻴﺔ ﻟﻠﻤﻌﺪﻥ ﺍﳌﺨﺘﱪ ﻭﺗﻌﻤﻞ ﺗﺸﻘﻘﺎﺕ ﲤﻴﻞ ﺑﺰﺍﻭﻳﺔ ‪ ٤٥‬ﺩﺭﺟـﺔ ﻣـﻊ‬ ‫ﺍﲡﺎﻩ ﲪﻞ ﺍﻟﺸﺪ ﺗﺪﻝ ﻋﻠﻰ ﺣﺪﻭﺙ ﺍﳋﻀﻮﻉ‪.‬‬ ‫‪ -٥‬ﻋﻨﺪ ﺣﺪﻭﺙ ﺍﳋﻀﻮﻉ ﻳﻼﺣﻆ ﺃﻧﻪ ﺇﺫﺍ ﻛﺎﻧﺖ ﺍﻟﻌﻴﻨﺔ ﻣﺸﻜﻠﺔ ﺑﺎﳌﺎﻛﻴﻨﺎﺕ ﻭﺳﻄﺤﻬﺎ ﻣﺼﻘﻮﻝ ﻻﻣـﻊ‬ ‫ﻓﺈﻧﻪ ﺗﻄﻬﺮ ﺧﻄﻮﻁ ﻣﺘﻮﺍﺯﻳﺔ ﻋﻠﻰ ﺳﻄﺤﻬﺎ ﺗﻌﻤﻞ ‪ ٤٥‬ﺩﺭﺟﺔ ﻣﻊ ﺍﲡﺎﻩ ﲪﻞ ﺍﻟﺸﺪ‪ ،‬ﳝﻜﻦ ﻣﻼﺣﻈﺘـﻬﺎ‬ ‫ﻭﺗﺴﺘﺨﺪﻡ ﻛﺒﻴﺎﻥ ﳊﻤﻞ ﺍﳋﻀﻮﻉ ﰱ ﺣﺎﻟﺔ ﻋﺪﻡ ﻭﺟﻮﺩ ﺃﺟﻬﺰﺓ ﺍﻹﻇﻬﺎﺭ ﺫﻟﻚ ﻭﻳﺮﺍﻋـﻰ ﺍﺳـﺘﺨﺪﺍﻡ‬ ‫ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﻟﻴﻌﱪ ﻋﻦ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﻟﻠﺸﺪ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﻭﻳﺴﺘﺨﺪﻡ ‪‬ﺬﻩ ﺍﻟﺼﻔﺔ ﻟﺘﺤﺪﻳـﺪ‬ ‫ﺇﺟﻬﺎﺩ ﺍﻟﺘﺸﻐﻴﻞ ﺃﻭ ﺇﺟﻬﺎﺩ ﺍﻟﺘﺼﻤﻴﻢ ﻟﻠﻤﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﲢﺖ ﺗﺄﺛﲑ ﺃﲪﺎﻝ ﺍﻟﺸﺪ ﺍﻻﺳﺘﺎﺗﻴﻜﻴﺔ ﻭﺫﻟﻚ ﻣﻦ‬ ‫ﺍﻟﻌﻼﻗﺔ ﺍﻵﺗﻴﺔ‪:‬‬ ‫‪٤٢‬‬


‫ﺇﺟﻬﺎﺩ ﺍﻟﺘﺸﻐﻴﻞ =‬

‫ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ‬ ‫ﻋﺎﻣﻞ ﺍﻷﻣﺎﻥ‬

‫ﻭﻋﺎﻣﻞ ﺍﻷﻣﺎﻥ ﻏﺎﻟﺒﺎ ﺗﺘﺮﻭﺍﺡ ﻗﻴﻤﺘﻪ ﺑﲔ ‪ ٣ : ٢‬ﻟﻠﻤﻌﺎﺩﻥ ﻣﻊ ﺍﺧﺘﻼﻑ ﺃﻧﻮﺍﻋﻬﺎ‪ ،‬ﻭﺃﻥ ﺍﺳﺘﺨﺪﺍﻡ ﺇﺟﻬـﺎﺩ‬ ‫ﺍﳋﻀﻮﻉ ﻟﻴﻌﱪ ﻋﻦ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﻳﺮﺟﻊ ﺇﱃ ﺃﻥ ﺍﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﻳﻘﺘـﺮﺏ ﻛـﺜﲑﹰﺍ ﰱ‬ ‫ﻗﻴﻤﺘﻪ ﻣﻦ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﺑﺎﻹﺿﺎﻓﺔ ﺇﱃ ﺛﺒﺎﺕ ﻗﻴﻤﺘﻪ ﻟﻠﻤﻌﺪﻥ ﺍﻟﻮﺍﺣﺪ ﻭﺇﻣﻜﺎﻧﻴﺔ ﺗﻌﻴﲔ ﻗﻴﻤﺘﻪ ﻣﻌﻤﻠﻴﹰﺎ ﺑﺪﻗﺔ‪.‬‬ ‫‪Proof Strength@@æbàšÛa@…bèug@TMSMR‬‬

‫ﺇﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ ﻫﻮ ﺍﳌﻘﺎﻭﻣﺔ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﻟﻠﻤﻌﺎﺩﻥ ﺍﻟﱴ ﳍﺎ ﺧﺎﺻﻴﺔ ﺍﳌﺮﻭﻧـﺔ ﻭﻟـﻴﺲ ﳍـﺎ ﻣﻨﻄﻘـﺔ‬ ‫ﺧﻀﻮﻉ‪ .‬ﺣﻴﺚ ﺗﻮﺟﺪ ﺑﻌﺾ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﻭﺍﻟﻨﺼﻒ ﻣﻄﻴﻠﺔ ﻭﺍﻟﱴ ﳍﺎ ﺧﺎﺻﻴﺔ ﺍﳌﺮﻭﻧﺔ ﻭﻟﻜﻦ ﻻ ﻳﻮﺟـﺪ‬ ‫‪‬ﺎ ﺃﻯ ﻣﻨﻄﻘﺔ ﻳﻈﻬﺮ ﻓﻴﻬﺎ ﺍﳋﻀﻮﻉ ‪ ،‬ﻭﰱ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻳﺘﺤﻮﻝ ﺍﳌﻨﺤﲎ ﻣﻦ ﻣﻨﻄﻘﺔ ﺍﳌﺮﻭﻧـﺔ‬ ‫ﺇﱃ ﻣﻨﻄﻘﺔ ﻣﺎ ﻓﻮﻕ ﺍﳌﺮﻭﻧﺔ ﲢﻮﻻ ﺗﺪﺭﳚﻴﺎ ﻛﻤﺎ ﻳﺘﻀﺢ ﻣﻦ ﺍﻟﺸﻜﻞ )‪ ،(١٣-٢‬ﺃﻯ ﺃﻧﻪ ﻻ ﻳﻮﺟـﺪ ﳍـﺬﻩ‬ ‫ﺍﳌﻌﺎﺩﻥ ﺇﺟﻬﺎﺩ ﺧﻀﻮﻉ ﻭﻧﻈﺮﹰﺍ ﻟﻮﺟﻮﺩ ﺧﺎﺻﻴﺔ ﺍﳌﺮﻭﻧﺔ ‪‬ﺬﻩ ﺍﳌﻌﺎﺩﻥ ﻓﺈﻧﻪ ﻳﻠﺰﻡ ﻣﻌﺮﻓﺔ ﺇﺟﻬﺎﺩ ﻳﻌـﱪ ﻋـﻦ‬ ‫ﺍﳌﻘﺎﻭﻣﺔ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﻭﻳﺴﻤﻰ ﻫﺬﺍ ﺍﻹﺟﻬﺎﺩ ﺑﺈﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ‪.‬‬

‫‪B‬‬

‫\\‬

‫ﺍﻻﻧﻔﻌﺎﻝ‬

‫ﺍﻹﺟﻬﺎﺩ ‪Stress‬‬

‫‪Proof Strength‬‬

‫\\‬

‫‪O‬‬

‫‪Strain‬‬ ‫‪0.002 of Gage Length‬‬

‫‪ ٠,٠٠٢‬ﻣﻦ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ‬

‫‘‪@ @æbàšÛa@…bèug@†í†znÛ@ÞbÈÐãüaë@…bèuüa@óäzäß@HQSMRI@ÝØ‬‬

‫‪٤٣‬‬


‫ﻭﳝﻜﻦ ﺗﻌﺮﻳﻒ ﺇﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ ﺑﺄﻧﻪ ﺍﻹﺟﻬﺎﺩ ﺍﻟﺬﻯ ﳛﺪﺙ ﰱ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﺍﺳﺘﻄﺎﻟﺔ ﻻ ﺗﻨﺎﺳﺒﻴﺔ ﻣﺴﺎﻭﻳﺔ‬ ‫ﻟﻨﺴﺒﺔ ﻣﺌﻮﻳﺔ ﻣﻌﻴﻨﺔ ﻣﻦ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ‪ .‬ﻭﻏﺎﻟﺒﺎ ﺗﺘﺮﺍﻭﺡ ﻗﻴﻤﺔ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﻟﻼ ﺗﻨﺎﺳﺒﻴﺔ ﺍﻟﱴ ﺗﺴﺘﺨﺪﻡ ﻟﺘﻌـﻴﲔ‬ ‫ﺇﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ ‪%٠,٢ : %٠,١‬ﻣﻦ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﺗﺒﻌﺎ ﳌﻮﺍﺻﻔﺎﺕ ﺍﳌﻌﺪﻥ ﻭﻟﺘﻌﻴﲔ ﺇﺟﻬﺎﺩ ﺍﻟـﻀﻤﺎﻥ‬ ‫ﻋﻠﻰ ﻣﻨﺤﲎ ﺍﻻﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻳﺘﻢ ﺗﻮﻗﻴﻊ ﻗﻴﻤﺔ ﺍﻻﻧﻔﻌﺎﻝ ﻋﻨﺪ ﻧﺴﺒﺔ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﳌﻄﻠﻮﺑﺔ ﻭﻟـﺘﻜﻦ ﻋﻨـﺪ‬ ‫‪ %٠,٢‬ﻣﻦ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻓﻴﻜﻮﻥ ﺍﻻﻧﻔﻌﺎﻝ ﻋﻨﺪ ﻫﺬﻩ ﺍﻻﺳﺘﻄﺎﻟﺔ ‪ ،٠,٠٠٢‬ﻭﺫﻟﻚ ﺑﻨﻘﻄﺔ ﻋﻠﻰ ﺍﶈـﻮﺭ‬ ‫ﺍﻷﻓﻘﻰ ﻟﺸﻜﻞ )‪ (١٣-٢‬ﻭﻣﻦ ﻫﺬﻩ ﺍﻟﻨﻘﻄﺔ ﻳﺘﻢ ﺭﺳﻢ ﺧﻂ ﻳﻮﺍﺯﻯ ﺍﳋﻂ ﺍﳌـﺴﺘﻘﻴﻢ ﻟﻠﻤـﻨﺤﲎ ﺍﻟﺒﻴـﺎﱏ‬ ‫ﻟﻺﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻟﻴﻘﺎﺑﻞ ﺍﳌﻨﺤﲎ ﰱ ﻧﻘﻄﺔ ﺗﻜﻮﻥ ﻫﻰ ﺇﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ‪.‬‬ ‫‪Elasticity@òãëŠ½a@UMSMR‬‬

‫ﺍﳌﺮﻭﻧﺔ ﻫﻰ ﺍﳊﺎﻟﺔ ﺍﻟﱴ ﺗﺴﺘﺮﺟﻊ ﻓﻴﻬﺎ ﺍﳌﺎﺩﺓ ﺃﺑﻌﺎﺩﻫﺎ ﺍﻷﺻﻠﻴﺔ ﺑﻌﺪ ﺯﻭﺍﻝ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ‪ .‬ﻭﺣﺎﻟـﺔ ﺍﳌﺮﻭﻧـﺔ‬ ‫ﺑﺎﳌﻌﺎﺩﻥ ﲢﺪﺙ ﰱ ﺍﳌﻨﻄﻘﺔ ﺍﻷﻭﱃ ﻣﻦ ﺍﻟﺘﺤﻤﻴﻞ ﻭﺗﻈﻬﺮ ﻋﻠﻰ ﻣﻨﺤﲎ ﺍﳊﻤـﻞ ﻭﺍﻹﺳـﺘﻄﺎﻟﺔ ﺃﻭ ﲟـﻨﺤﲎ‬ ‫ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻋﺒﺎﺭﺓ ﻋﻦ ﺧﻂ ﻣﺴﺘﻘﻴﻢ ﻭﲤﺜﻞ ﻣﻨﻄﻘﺔ ﺍﳌﺮﻭﻧﺔ ﺑﺎﳌﻨﻄﻘﺔ ﺍﻟﻮﺍﻗﻌﺔ ﲢﺖ ﺍﳉﺰﺀ ﺍﳌﻜﻮﻥ ﻣﻦ‬ ‫ﺧﻂ ﻣﺴﺘﻘﻴﻢ ﲟﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ‪.‬‬ ‫‪Stiffness@@òiý–Ûa@VMSMR‬‬

‫ﺍﻟﺼﻼﺑﺔ ﻫﻰ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﻟﻠﺘﻐﲑ ﰱ ﺍﻟﺸﻜﻞ ﺑﺘﺤﻤﻴﻞ ﺍﳌﻌﺪﻥ ﰱ ﺍﻟﺸﺪ ﺃﻯ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﻟﻼﺳـﺘﻄﺎﻟﺔ‬ ‫ﻭﺗﻘﺎﺱ ﺍﻟﺼﻼﺑﺔ ﲟﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ )‪ (Modulus of Elasticity‬ﻭﻳـﺴﻤﻰ ﻣﻌـﺎﻳﺮ ﻳـﺎﻧﺞ‬

‫‪(Young’s‬‬

‫)‪ Modulus‬ﻭﻫﻮ ﻳﺴﺎﻭﻯ ﺍﻟﺰﻳﺎﺩﺓ ﰱ ﺍﻻﺟﻬﺎﺩ ﻣﻘﺴﻮﻣﺔ ﻋﻠﻰ ﺍﻟﺰﻳﺎﺩﺓ ﰱ ﺍﻻﻧﻔﻌﺎﻝ ﺃﻯ ﺃﻥ‪:‬‬ ‫ﺍﻹﺟﻬﺎﺩ‬

‫‪σ‬‬

‫‪ E = ε‬ﺍﳌﻤﺜﻠﺔ ﳌﺮﺣﻠﺔ ﺍﳌﺮﻭﻧﺔ ‪ ،‬ﻭﻳﺘﻢ ﺗﻌﻴﲔ ﻣﻌـﺎﻳﺮ‬ ‫ﺍﻟﺼﻼﺑﺔ = ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ =‬ ‫ﺍﻻﻧﻔﻌﺎﻝ‬ ‫ﺍﳌﺮﻭﻧﺔ ﻋﻠﻰ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﲟﻴﻞ ﺍﳋﻂ ﺍﳌﺴﺘﻘﻴﻢ ﻭﻭﺣﺪﺍﺕ ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧـﺔ ﻫـﻰ ﻭﺣـﺪﺍﺕ‬ ‫ﺇﺟﻬﺎﺩ‪ ،‬ﻭﲣﺘﻠﻒ ﺻﻼﺑﺔ ﺍﳌﻌﺎﺩﻥ ﺑﺎﺧﺘﻼﻑ ﻗﻴﻤﺔ ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﳍﺎ‪.‬‬ ‫ﻭﺗﻘﺎﺱ ﺻﻼﺑﺔ ﺍﳌﻌﺎﺩﻥ ﺍﻟﱴ ﻻ ﻳﻮﺟﺪ ﳍﺎ ﺧﻂ ﻣﺴﺘﻘﻴﻢ ﲟﻨﺤﲎ ﺍﻻﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺑﻌﺪ ﲤﺜﻴﻠﺔ ﺑﻮﺍﺳـﻄﺔ ‪@Šíb;Èß‬‬

‫‪ (Initial Tangent Modulus) µ‬ﻭﻫﻮ ﻋﺒﺎﺭﺓ ﻋﻦ ﻣﻴﻞ ﺍﳌﻤﺎﺱ ﳌﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻵﻧﻔﻌـﺎﻝ‬ ‫‪@ ëþa@÷b;ànÛa‬‬ ‫ﻋﻨﺪ ‪ Ý@ ;•þa@òĐÔã‬ﺃﻯ ﺑﺪﺍﻳﺔ ﺍﳌﻨﺤﲎ ﻛﻤﺎ ﺗﺒﲔ ﻣﻦ ﺍﻟﺸﻜﻞ )‪ (١٤-٢‬ﻛﻤﺎ ﳝﻜﻦ ﻣﻘﺎﺭﻧﺔ ﺻﻼﺑﺔ ﻣﺜـﻞ ﻫـﺬﻩ‬ ‫ﺍﳌﻌﺎﺩﻥ ﻋﻨﺪ ﺃﻯ ﺇﺟﻬﺎﺩ ﻣﻌﲔ ﺑﻮﺍﺳﻄﺔ ‪ (Tangent Modulus) ÷bànÛa@ŠíbÈß‬ﻭﻫﻮ ﻣﻴﻞ ﺍﳌﻤﺎﺱ ﳌﻨﺤﲎ‬ ‫‪٤٤‬‬


‫ﺍﻹﺟﻬﺎﺩ ‪Stress‬‬

‫‪D‬‬ ‫‪B‬‬

‫‪A‬‬

‫‪σ‬‬ ‫‪θ‬‬ ‫‪γ ε‬‬

‫ﺍﻻﻧﻔﻌﺎﻝ‬

‫‪σ‬‬ ‫‪E = tan θ = ε‬‬ ‫‪γ‬‬ ‫‪γ‬‬

‫‪Strain‬‬

‫‪C‬‬

‫‪O‬‬

‫‘‪@ @óäzä½bi@áîÔnß@Á@b@†uìí@ü@Ûa@æ…bÈàÜÛ@òãëŠ½a@ŠíbÈß@´îÈm@HQTMRI@ÝØ‬‬

‫ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻋﻨﺪ ﺍﻟﻨﻘﻄﺔ ﻋﻠﻰ‬

‫ﺍﳌﻨﺤﲎ ﺍﻟﱴ ﺗﻘﺎﺑﻞ ﺍﻹﺟﻬﺎﺩ ﺍﳌﻌﲔ ﺍﳌﺬﻛﻮﺭ ﻭﻟﻴﻜﻦ ﻋﻨﺪ ﺍﻟﻨﻘﻄـﺔ ‪A‬‬

‫ﻛﻤﺎ ﰱ ﺷﻜﻞ )‪ (١٤-٢‬ﻭﺗﻠﻚ ﺍﳌﻘﺎﺭﻧﺔ ﻟﻠﺼﻼﺑﺔ ﻋﻨﺪ ﺇﺟﻬﺎﺩ ﻣﻌﲔ ﻗﺪ ﺗﻜﻮﻥ ﺃﻳﻀﺎ ﺑﻮﺍﺳﻄﺔ ‪@ÉbÔÛa@ŠíbÈß‬‬

‫)‪ (Secant Modulus‬ﻭﻫﻮ ﻣﻴﻞ ﺍﳋﻂ )‪ (O B‬ﺍﻟﻮﺍﺻﻞ ﺑﲔ ﻧﻘﻄﺔ ﺍﻷﺻﻞ ﻭﺍﻟﻨﻘﻄﺔ ﺍﳌﻮﺟﻮﺩﺓ ﻋﻠـﻰ‬ ‫ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﱴ ﺗﻘﺎﺑﻞ ﺍﻹﺟﻬﺎﺩ ﺍﳌﻌﲔ ﺍﳌﻌﺮﻭﻑ‪ .‬ﻛﺬﻟﻚ ﳝﻜﻦ ﺍﻟﺘﻌﺒﲑ ﻋﻦ ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧـﺔ‬ ‫¶‪ (Chord Modulus) ŠmìÛa@ŠíbÈ‬ﻭﻫﻮ ﻣﻴﻞ ﺍﳋﻂ ﺍﻟﻮﺍﺻﻞ ﺑﲔ ﻧﻘﻄﺘﲔ ﳏﺪﺩﺗﲔ ﻋﻠﻰ ﺍﳌﻨﺤﲎ ﻣﺜـﻞ‬ ‫ﺍﻟﻨﻘﻄﺘﲔ ِ ‪ ٠ D ، C‬ﻭﻟﺘﺤﺪﻳﺪ ﻭﺗﻌﻴﲔ ﻗﻴﻤﺔ ﺍﻟﺼﻼﺑﺔ ﻟﻠﻤﻌﺎﺩﻥ ﺃﳘﻴﺔ ﻛﱪﻯ ﰱ ﻋﻤﻠﻴﺎﺕ ﻭﺍﻟﺘﺸﻜﻴﻞ ﺑﺘﺄﺛﲑ‬ ‫ﺍﻷﲪﺎﻝ ﺍﳌﺨﺘﻠﻔﺔ ﻟﻠﻤﻌﺎﺩﻥ‪.‬‬ ‫‪@ @Resilience@@òîÇìuŠÛa@WMSMR‬‬ ‫‪Šqû½a@Ýà§a@Þaë‹@†Èi@òîãbq@bèÈuŠí@áq@ÝîàznÛa@†äÇ@bèãŒn±@æc@æ†ÈàÜÛ@åØ¹@ónÛa@òÓbĐÛa@òîà×@óç@òîÇìuŠÛa‬‬

‫ﻭ ﻫﻰ ﺧﺎﺻﻴﺔ ﺗﻜﻮﻥ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﻟﻠﻤﻌﺪﻥ‪ ،‬ﻭﺗﻘﺪﺭ ﺍﻟﺮﺟﻮﻋﻴﺔ ﺑﻘﻴﻤﺔ ﺍﻟﺸﻐﻞ ﺍﳌﺒـﺬﻭﻝ ﺑﺎﻟﺘﺤﻤﻴـﻞ‬ ‫ﻹﺣﺪﺍﺙ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺣﱴ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ‪.‬‬ ‫‪@ @NkbänÛa@†y@†äÇ@òÛbĐnüa@F@kbänÛa@†§@ÝibÔ½a@Ýà§a@½@]@òîÇìuŠÛa‬‬

‫ﺃﻯ ﺃﻥ ﺍﻟﺮﺟﻮﻋﻴﺔ ﺗﺴﺎﻭﻯ ﻣﺴﺎﺣﺔ ﺍﳌﺜﻠﺚ ﲢﺖ ﺍﳋﻂ ﺍﳌﺴﺘﻘﻴﻢ ﻟﻠﻤﻨﺤﲎ ﺍﻟﺒﻴﺎﱏ ﻟﻠﺤﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﻛﻤﺎ‬ ‫ﻳﺘﺒﲔ ﰱ ﺷﻜﻞ )‪.(١٥-٢‬‬ ‫‪٤٥‬‬


‫ا&"( ‬ ‫"ق او ‬ ‫‪Hyper‬‬ ‫‪Elastic‬‬ ‫‪Resilience‬‬

‫ا‪%&,‬د ‪Stress‬‬

‫ا* ‪Load‬‬

‫ﺃ‬

‫ا&"( ا ‬ ‫‪Elastic Resilience‬‬

‫‪ 0.‬ا&"( ‬ ‫‪Modulus of Resilience‬‬

‫ﺏ‬ ‫ا‪./‬ل ‪Strain‬‬

‫ا ‪Deformation‬‬

‫‘‪@ @òîÇìuŠÛa@ŠíbÈßë@òîÇìuŠÛa@HQUMRI@ÝØ‬‬

‫ﻭﻳﻌﺘﱪ ‪ (Modulus of Resilience) ò@ ;îÇìuŠÛa@ŠíbÈß‬ﻳﺴﺎﻭﻯ ﻗﻴﻤﺔ ﺍﻟﺮﺟﻮﻋﻴﺔ ﻣﻘﺴﻮﻣﺎ ﻋﻠﻰ ﺣﺠـﻢ‬ ‫ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ‪.‬‬ ‫‪@ @kbänÛa@†y@†äÇ@ÞbÈÐãüa@F@…bèu⁄a@½@]@òîÇìuŠÛa@ŠíbÈß‬‬

‫ﺃﻯ ﺃﻥ ﻣﻌﺎﻳﺮ ﺍﻟﺮﺟﻮﻋﻴﺔ ﺗﻘﺪﺭ ﺑﺎﳌﺴﺎﺣﺔ ﲢﺖ ﺍﳋﻂ ﺍﳌﺴﺘﻘﻴﻢ ﻣﻦ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻹﻧﻔﻌﺎﻝ ﻛﻤـﺎ ﻫـﻮ‬ ‫ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ .(١٥-٢‬ﺃﻣﺎ ‪ (Hyper–Elastic Resilience) ò@ ;ãëŠ½a@†y@ÖìÏ@òîÇìuŠÛa‬ﻓﻬـﻰ‬ ‫ﻋﺒﺎﺭﺓ ﻋﻦ ﺍﻟﻄﺎﻗﺔ ﺍﻟﱴ ﻳﺮﺟﻌﻬﺎ ﺍﳌﻌﺪﻥ ﺑﻌﺪ ﺇﺯﺍﻟﺔ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻭﻫﻰ ﺟﺰﺀ ﻣﻦ ﺍﻟﺸﻐﻞ ﺍﳌﺒﺬﻭﻝ ﺑﺎﻟﺘﺤﻤﻴـﻞ‬ ‫ﻓﻮﻕ ﺣﺪ ﺍﳌﺮﻭﻧﺔ‪ .‬ﻭﻫﻰ ﻋﺒﺎﺭﺓ ﻋﻦ ﺍﻟﻄﺎﻗﺔ ﺍﳌﺮﲡﻌﺔ ﻋﻨﺪ ﺃﻯ ﲪﻞ ﻭﺗﻘﺎﺱ ﺑﺎﳌﺴﺎﺣﺔ ﲢﺖ ﻣﻨﺤﲎ ﺍﳊﻤـﻞ‬ ‫ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﻭﻫﻰ ﺍﳌﺴﺎﺣﺔ ﺍﶈﺪﻭﺩﺓ ﲞﻂ ﻳﻮﺍﺯﻯ ﺧﻂ ﺍﳌﻨﺤﲎ ﳌﻨﻄﻘﺔ ﺍﳌﺮﻭﻧﺔ ﻭﺃﻳـﻀﺎ ﺑـﺎﳋﻂ ﺍﳌـﻮﺍﺯﻯ‬ ‫ﻟﻠﻤﺤﻮﺭ ﺍﻟﺮﺃﺱ ﺍﳌﺒﲔ ﻟﻠﺤﻤﻞ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ .(١٥-٢‬ﻭﻳﻜﻮﻥ ﻣﻌﺎﻳﺮ ﺗﻠﻚ ﺍﻟﺮﺟﻮﻋﻴﺔ ﻫﻰ‬ ‫ﺍﳌﺴﺎﺣﺔ ﲢﺖ ﺍﳌﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺍﳌﻘﺎﺑﻠﺔ ﻟﻠﻤﺴﺎﺣﺔ ﺍﳌﺬﻛﻮﺭﺓ ﲢﺖ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ‪.‬‬ ‫‪@ @@@@Toughness@@@òãbn½a@XMSMR‬‬ ‫ﺗﻌﱪ ﻋﻦ ‪ ò@ ;ãbn½a‬ﺑﺎﻟﻄﺎﻗﺔ ﺍﳌﺒﺬﻭﻟﺔ ﺑﺘﺤﻤﻴﻞ ﺍﳌﻌﺪﻥ ﺑﺎﻟﺸﺪ ﺣﱴ ﺍﻟﻜﺴﺮ ﺗﻌﱪ ﻋﻦ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻟﻠﻤﻌﺪﻥ‬ ‫ﻟﺘﺤﻤﻞ ﺍﳊﻤﻞ ﺍﻟﺪﻳﻨﺎﻣﻴﻜﻰ ﺃﻯ ﺍﳌﻘﺎﻭﻣﺔ ﻟﻠﺼﺪﻡ ﺍﻟﻨﺎﺗﺞ ﻣﻦ ﺃﲪﺎﻝ ﺍﻟﺸﺪ‪ .‬ﻭﻫﺬﻩ ﺍﻟﻄﺎﻗﺔ ﻋﺒﺎﺭﺓ ﻋﻦ ﳎﻤﻮﻋﺔ‬ ‫ﺍﻟﺸﻐﻞ ﺍﳌﺒﺬﻭﻝ ﻣﻦ ﺍﻷﲪﺎﻝ ﺍﳌﺆﺛﺮﺓ ﺣﱴ ﺍﻟﻜﺴﺮ ﺃﻯ ﺗﺴﺎﻭﻯ ﳎﻤﻮﻉ ﺍﳊﻤﻞ ﰱ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﳌﻘﺎﺑﻠﺔ ﳍـﺬﺍ‬ ‫ﺍﳊﻤﻞ ﺣﱴ ﺍﻟﻜﺴﺮ‪ ،‬ﺃﻯ ﺗﺴﺎﻭﻯ ﺍﳌﺴﺎﺣﺔ ﲢﺖ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ‪ .‬ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟـﺸﻜﻞ‬ ‫)‪ .(١٦-٢‬ﺃﻣﺎ ‪ (Modulus of Toughness) ò@ ;ãbn½a@ŠíbÈß‬ﻓﻬﻮ ﻋﺒﺎﺭﺓ ﻋﻦ ﺍﳌﻘﺎﻭﻣﺔ ﻟﻠﺼﺪﻡ ﻣﻘﺴﻮﻣﺔ‬ ‫ﻋﻠﻰ ﺣﺠﻢ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺍﻟﱴ ﺗﺴﺎﻭﻯ ﺍﳌﺴﺎﺣﺔ ﲢﺖ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻛﻤﺎ ﻳﺘﺒﲔ ﻣﻦ ﺍﻟﺸﻜﻞ‬ ‫)‪ (١٦-٢‬ﻓﻜﻠﻤﺎ ﺍﺯﺩﺍﺩﺕ ﻫﺬﻩ ﺍﳌﺴﺎﺣﺔ ﻛﻠﻤﺎ ﻛﱪﺕ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﻟﻸﲪﺎﻝ ﺍﻟﺪﻧﻴﺎﻣﻴﻜﻴﺔ ﺃﻯ ﺍﳌﻘﺎﻭﻣـﺔ‬ ‫ﻟﻠﺼﺪﻡ‪.‬‬ ‫‪٤٦‬‬


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‫‪ 5( 6‬ا‪"4‬ن‬ ‫‪ 7" 6‬ا‪"4‬ن‬

‫‪ 8$ 6‬ا‪"4‬ن‬

‫ا‪./‬ل ‪Strain‬‬



‫‘‪@ @òÐÜn«@æ…bÈ½@òãbn½a@ŠíbÈß@HQVMRI@ÝØ‬‬

‫@@‬ ‫‪@ @Hysteresis @@òîÐÜ‚nÛa@YMSMR‬‬ ‫ﻋﻨﺪ ﲢﻤﻴﻞ ﻣﻌﺪﻥ ﻓﻮﻕ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﲝﻤﻞ ﻣﻌﲔ ﰒ ﺃﺯﻳﻞ ﻫﺬﺍ ﺍﳊﻤﻞ ﰒ ﺃﻋﻴﺪ ﺍﻟﺘﺤﻤﻴﻞ ﺛﺎﻧﻴﺔ ﻓﺈﻥ ﻣـﻨﺤﲎ‬ ‫ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻗﺪ ﳛﺘﻮﻯ ﰱ ﺑﻌﺾ ﺍﻷﺣﻴﺎﻥ ﻋﻠﻰ ﺃﻧﺸﻮﻃﺔ )‪ (Loop‬ﻣﻜﻮﻧﺔ ﻣﻦ ﺧﻄـﲔ ﻣﻨﺤـﻨﲔ‬ ‫ﺑﺪﻻ ﻣﻦ ﺧﻂ ﻣﺴﺘﻘﻴﻢ ﻭﺍﺣﺪ ﻛﺎﳌﻌﺘﺎﺩ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ ،(١٧-٢‬ﻭﺗﺴﻤﻰ ﺗﻠﻚ ﺍﻷﻧـﺸﻮﻃﺔ‬ ‫ﺑﺎﻻﻧﺸﻮﻃﺔ ﺍﻟﺘﺨﻠﻔﻴﺔ‪ .‬ﻭﺗﻜﻮﻥ ﺍﳌﺴﺎﺣﺔ ﺍﻟﺪﺍﺧﻠﻴﺔ ﻟﻸﻧﺸﻮﻃﺔ ﳌﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻋﺒﺎﺭﺓ ﻋﻦ ﺍﻟﻄﺎﻗﺔ‬ ‫ﺍﳌﻔﻘﻮﺩﺓ ﺍﻟﻨﺎﲡﺔ ﻣﻦ ﺩﻭﺭﺓ ﻭﺍﺣﺪﺓ ﻣﻦ ﺯﻭﺍﻝ ﺍﳊﻤﻞ ﰒ ﺇﻋﺎﺩﺗﻪ ﺛﺎﻧﻴﺔ‪.‬‬

‫‪Hystersis‬‬


‫‘‪@ @ôŠĐÛa@kÜ–ÜÛ@òîÐÜ‚nÛa@HQWMSI@ÝØ‬‬

‫‪٤٧‬‬


‫ا‪ $‬‬


‫ﻭﺍﻟﺘﺨﻠﻔﻴﺔ ﻇﺎﻫﺮﺓ ﻣﻬﻤﺔ ﻳﻠﺰﻡ ﻣﻌﺮﻓﺔ ﻣﺪﻯ ﺗﻮﺍﺟﺪﻫﺎ ﺑﺎﳌﺎﺩﺓ ﺣﻴﺚ ﺃﻥ ﻭﺟﻮﺩﻫﺎ ﻳﺴﺒﺐ ﺍﺭﺗﻔﺎﻋﹰﺎ ﰱ ﺩﺭﺟﺔ‬ ‫ﺍﳊﺮﺍﺭﺓ ﻟﻠﻤﺎﺩﺓ ﺑﺴﺒﺐ ﺍﳊﺮﺍﺭﺓ ﺍﳌﺘﺮﺍﻛﻤﺔ ﻣﻦ ﺍﻟﻄﺎﻗﺔ ﺍﳌﻔﻘﻮﺩﺓ ﺑﺎﺳﺘﻤﺮﺍﺭ ﻣﻦ ﺍﻟﺘﺤﻤﻴﻞ ﻭﺇﺯﺍﻟﺔ ﺍﻟﺘﺤﻤﻴـﻞ‬ ‫ﻭﻫﺬﺍ ﻳﻀﻌﻒ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻠﻤﻮﺍﺩ ﳑﺎ ﻳﺆﺛﺮ ﻋﻠﻰ ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻸﲪﺎﻝ ﻋﻦ ﺍﳌﺎﺩﺓ ﺍﻟﱴ ﻻ ﻳﻮﺟﺪ ‪‬ـﺎ‬ ‫ﻫﺬﻩ ﺍﻟﻈﺎﻫﺮﺓ‪.‬‬ ‫‪Strength@@òßëbÔ½a@QPMSMR‬‬

‫ﻭﻳﻮﺟﺪ ﻣﻘﺎﻭﻣﺘﲔ ﻣﻬﻤﺘﲔ ﻟﻠﻤﻌﺎﺩﻥ ﰱ ﺍﻟﺸﺪ ﻭﳘﺎ‪:‬‬ ‫‪. !' -!" )* (-. / 0!10 -1‬‬ ‫ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻟﻠﻤﻌﺎﺩﻥ ﺍﻟﱴ ﳍﺎ ﺧﺎﺻﻴﺔ ﺍﳌﺮﻭﻧﺔ ﺃﻯ ﺍﻟﱴ ﳍﺎ ﺣﺪ ﺗﻨﺎﺳﺐ ﻭﺣﺪ ﻣﺮﻭﻧﺔ ﻣﻊ ﻭﺟﻮﺩ ﻣﻨﻄﻘـﺔ‬ ‫ﺧﻀﻮﻉ ﺃﻭ ﻟﻠﻤﻌﺎﺩﻥ ﺍﻟﱴ ﳍﺎ ﺧﺎﺻﻴﺔ ﺍﳌﺮﻭﻧﺔ ﻭﻟﻴﺲ ‪‬ﺎ ﻣﻨﻄﻘﺔ ﺧﻀﻮﻉ ﻭﺍﳌﻘﺎﺑﻞ ﻹﺟﻬﺎﺩ ﺍﳋـﻀﻮﻉ ‪‬ـﺎ‬ ‫ﺇﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ ﻭﻫﻨﺎ ﻳﻜﻮﻥ ﺃﻗﺼﻰ ﺇﺟﻬﺎﺩ ﳌﺮﺣﻠﺔ ﺍﳌﺮﻭﻧﺔ ﻛﻤﺎ ﻳﻠﻰ‪:‬‬ ‫ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ =‬

‫ﲪﻞ ﺍﳋﻀﻮﻉ‬ ‫ﺍﳌﺴﺎﺣﺔ ﺍﻷﺻﻠﻴﺔ‬

‫=‬

‫ﲪﻞ ﺍﻟﻀﻤﺎﻥ‬ ‫ﺍﳌﺴﺎﺣﺔ ﺍﻷﺻﻠﻴﺔ‬

‫ﻭﺗﺴﺘﺨﺪﻡ ﺗﻠﻚ ﺍﳌﻘﺎﻭﻣﺔ ﰱ ﺃﻋﻤﺎﻝ ﺍﻟﺘﺼﻤﻴﻢ ﻟﺘﻌﻴﲔ ﺍﻹﺟﻬﺎﺩ ﺍﻟﺘﺼﻤﻴﻤﻰ ﺃﻭ ﺇﺟﻬﺎﺩ ﺍﻟﺘـﺸﻐﻴﻞ‪ .‬ﻭﺫﻟـﻚ‬ ‫ﺑﻘﺴﻤﺔ ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﺃﻭ ﺇﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ ﻋﻠﻰ ﻋﺎﻣﻞ ﺃﻣﺎﻥ ﳛﺪﺩﻩ ﺍﳌﺼﻤﻢ ﺃﻭ ﻛﻮﺩ ﺍﻟﺘﻨﻔﻴﺬ‪٠‬‬ ‫ﺍﻹﺟﻬﺎﺩ ﺍﻟﺘﺼﻤﻴﻤﻰ= ﺇﺟﻬﺎﺩ ﺍﻟﺘﺸﻐﻴﻞ=‬

‫ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ‬ ‫ﻋﺎﻣﻞ ﺍﻷﻣﺎﻥ‬

‫=‬

‫ﺇﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ‬ ‫ﻋﺎﻣﻞ ﺍﻷﻣﺎﻥ‬

‫‪/ 3 1 0!1' -2‬‬ ‫ﺗﻌﲔ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻟﻠﺸﺪ ﰱ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﻭﻻ ﺗﻌﱪ ﺑﺪﻗﺔ ﻋﻦ ﻣﻘﺎﻭﻣﺘﻬﺎ ﺍﻟﻘﺼﻮﻯ ﻟﻮﺟـﻮﺩ ﺗﻐـﲑ‬ ‫ﻣﻠﺤﻮﻅ ﲟﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﻋﻨﺪ ﺃﻗﺼﻰ ﲪﻞ ﺷﺪ ﺣﻴﺚ ﻳﻜﻮﻥ ﻋﻨﺪﻩ ﺑﺪﺍﻳﺔ ﺗﻜﻮﻥ ﺍﻟﺮﻗﺒﺔ‪ .‬ﺃﻣﺎ ﰱ ﺣﺎﻟﺔ ﺍﳌﻌﺎﺩﻥ‬ ‫ﺍﻟﻘﺼﻔﺔ ﻓﺘﻜﻮﻥ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﺍﻟﻘﺼﻮﻯ ﳑﺜﻠﺔ ﲤﺎﻣﺎ ﻷﻗﺼﻰ ﻣﻘﺎﻭﻣﺔ ﻳﺘﻌﺮﺽ ﳍـﺎ ﺍﳌﻌـﺪﻥ ﻷﻥ ﺍﳌﻘﻄـﻊ‬ ‫ﺍﳌﺴﺘﻌﺮﺽ ﻻ ﻳﺘﻐﲑ ﻋﻦ ﺍﻟﻜﺴﺮ ﺇﻻ ﺑﻘﻴﻤﺔ ﺻﻐﲑﺓ ﳝﻜﻦ ﺇﳘﺎﳍﺎ‪ ،‬ﻛﻤﺎ ﺃﻥ ﺍﳊﻤﻞ ﺍﻷﻗﺼﻰ ﻫﻮ ﲪﻞ ﺍﻟﻜﺴﺮ‬ ‫ﻧﻔﺴﻪ‪ ٠‬ﻭﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻟﻠﺸﺪ ﺗﺴﺎﻭﻯ ﺍﳊﻤﻞ ﺍﻷﻗﺼﻰ ﺍﻟﺬﻯ ﺗﻌﺮﺿﺖ ﻟﻪ ﻋﻴﻨﺔ ﺍﻟﺸﺪ ﻣﻘﺴﻮﻣﹰﺎ ﻋﻠـﻰ‬ ‫ﺍﳌﺴﺎﺣﺔ ﺍﻷﺻﻠﻴﺔ ﻟﻠﻤﻘﻄﻊ‪.‬‬ ‫‪٤٨‬‬


‫ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻟﻠﺸﺪ =‬

‫ﺃﻗﺼﻰ ﲪﻞ‬ ‫ﺍﳌﺴﺎﺣﺔ ﺍﻷﺻﻠﻴﺔ‬

‫‪Ductility@@òîÛìĐà½a@QQMSMR‬‬

‫ﺗﻌﲔ ﺍﳌﻤﻄﻮﻟﻴﺔ ﻟﻠﻤﻌﺎﺩﻥ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﲝﺴﺎﺏ ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻼﺳﺘﻄﺎﻟﺔ ﺃﻭ ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻠـﻨﻘﺺ ﰱ‬ ‫ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﻟﻠﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ‪.‬‬ ‫‪ -١‬ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻼﺳﺘﻄﺎﻟﺔ =‬

‫ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﺑﻌﺪ ﺍﻟﻜﺴﺮ – ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ‬ ‫ﺍﻷﺻﻠﻰ‬

‫× ‪١٠٠‬‬

‫‪Elongation % = Li – L0 x 100‬‬ ‫‪L0‬‬

‫‪ -٢‬ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻠﻨﻘﺺ ﰱ ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ =‬ ‫ﺍﳌﺴﺎﺣﺔ ﺍﻷﺻﻠﻴﺔ ﻟﻠﻤﻘﻄﻊ – ﺍﳌﺴﺎﺣﺔ ﺃﺻﻐﺮ ﻣﻘﻄﻊ ﺑﻌﺪ ﺍﻟﻜﺴﺮ‬ ‫ﺍﳌﺴﺎﺣﺔ ﺍﻷﺻﻠﻴﺔ ﻟﻠﻤﻘﻄﻊ‬ ‫‪A0 – Ai‬‬ ‫‪x 100‬‬ ‫‪A0‬‬

‫=‬

‫× ‪١٠٠‬‬

‫‪Reduction of area %‬‬

‫ﻭﳝﻜﻦ ﻣﻘﺎﺭﻧﺔ ﳑﻄﻮﻟﻴﺔ ﺍﳌﻌﺎﺩﻥ ﻣﺒﺎﺷﺮﺓ ﻣﻦ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﻋﻨﺪ ﺗﻌﻴﲔ ﻗﻴﻤﺔ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻋﻨـﺪ‬ ‫ﺍﻟﻜﺴﺮ ﺃﻭ ﻣﻦ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﲟﻌﺮﻓﺔ ﻗﻴﻤﺔ ﺃﻛﱪ ﺍﻧﻔﻌﺎﻝ‪.‬‬ ‫‪Elongation@@òÛbĐnüa@@QRMSMR‬‬

‫ﻋﻨﺪﻣﺎ ﻳﺘﻢ ﺗﻮﺯﻳﻊ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻋﻠﻰ ﲨﻴﻊ ﺍﳌﻮﺍﺿﻊ ﺍﳌﻮﺿﺤﺔ ﻋﻠﻰ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻭﺗﻜﻮﻥ ﻣﻘﺴﻤﺔ ﺗﻘـﺴﻴﻤﺎ‬ ‫ﻣﺘﺴﺎﻭﻳﺎ ﻭﺇﺫﺍ ﻛﺎﻥ ﲪﻞ ﺍﻟﺸﺪ ﺍﳌﺆﺛﺮ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﻓﺈﻥ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺗﻜﻮﻥ ﻣﺘﺴﺎﻭﻳﺔ ﻭﻣﻨﺘﻈﻤﺔ‪ ،‬ﻭﻋﻨﺪﻣﺎ‬ ‫ﺗﺘﻌﺪﻯ ﺍﻟﻌﻴﻨﺔ ﺍﶈﻤﻠﺔ ﻣﻨﻄﻘﺔ ﺍﳌﺮﻭﻧﺔ ﻳﻜﻮﻥ ﺗﻮﺯﻳﻊ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻋﻠﻰ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻏﲑ ﻣﻨﺘﻈﻢ ﻭﺗﺰﺩﺍﺩ ﻗﻴﻤﺔ‬ ‫ﺍﻻﺳﺘﻄﺎﻟﺔ ﻛﻠﻤﺎ ﺍﲡﻬﻨﺎ ﻟﻠﺪﺍﺧﻞ ﺣﻴﺚ ﺗﻜﻮﻥ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺃﻛﱪ ﻋﻨﺪ ﻣﻨﻄﻘﺔ ﺣﺪﻭﺙ ﺍﻟﺮﻗﺒﺔ ﰒ ﺗﺰﺩﺍﺩ ﺍﻟﻘﻴﻤﺔ‬ ‫ﺣﱴ ﺍﻟﻜﺴﺮ ﻟﻠﻌﻴﻨﺔ ﻟﻴﺤﻘﻖ ﺃﻛﱪ ﺍﺳﺘﻄﺎﻟﺔ ﻋﻨﺪ ﺍﻟﻜﺴﺮ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪.(١٨-٢‬‬ ‫‪٤٩‬‬


‫ﺍﻻﺳﺘﻄﺎﻟﺔ )‪(%‬‬

‫‪٠ ٢ ٤ ٦ ٨ ١٠ ١٢ ١٤ ١٦ ١٨‬‬ ‫ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ )ﺳﻢ(‬

‫ﺍﻻﺳﺘﻄﺎﻟﺔ ‪ -‬ﻣﻢ‬

‫‪٨٠‬‬ ‫‪٧٠‬‬ ‫‪٦٠‬‬ ‫‪٥٠‬‬ ‫‪٤٠‬‬ ‫‪٣٠‬‬ ‫‪٢٠‬‬ ‫‪١٠‬‬ ‫‪٠‬‬

‫‪٢٤‬‬ ‫‪٢٠‬‬ ‫‪١٦‬‬ ‫‪١٢‬‬ ‫‪٨‬‬ ‫‪٤‬‬ ‫‪٠‬‬ ‫ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻣﻘﺴﻢ ﺇﱃ ﻭﺣﺪﺍﺕ‬

‫ ‪0( 1 2 3‬‬

‫(‪2 0 '4 56 1 0‬‬

‫‘‪@ @òÛbĐnüa@óÜÇ@òäîÈÛa@Þì@qdm@HQXMRI@ÝØ‬‬

‫ﻭﻣﻦ ﻫﻨﺎ ﻳﺘﺒﲔ ﺃﻥ ﺍﻻﺳﺘﻄﺎﻟﺔ ﲣﺘﻠﻒ ﺑﺎﺧﺘﻼﻑ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻭﺃﻥ ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻼﺳـﺘﻄﺎﻟﺔ ﺗﺘﻨﺎﺳـﺐ‬ ‫ﺗﻨﺎﺳﺒﺎ ﻋﻜﺴﻴﺎ ﻣﻊ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻟﻠﻌﻴﻨﺔ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ ،(١٨-٢‬ﻭﻳﺘﻀﺢ ﺃﻳﻀﹰﺎ ﺃﻥ ﻃـﻮﻝ‬ ‫ﺍﻟﻘﻴﺎﺱ ﺍﻟﻘﺼﲑ ﻟﻪ ﺍﺳﺘﻄﺎﻟﺔ ﻛﺒﲑﺓ ﻭﺍﻟﻌﻜﺲ ﺻﺤﻴﺢ ﻟﻠﻤﻌﺪﻥ ﺍﻟﻮﺍﺣﺪ ﻭﻋﻠﻴﻪ ﻓﺈﻧﻪ ﻋﻨﺪ ﺇﺟـﺮﺍﺀ ﺍﺧﺘﺒـﺎﺭ‬ ‫ﺍﻟﺸﺪ ﺍﻟﻘﻴﺎﺳﻰ ﳚﺐ ﺗﻮﺣﻴﺪ ﻗﻴﻤﺔ ﻃﻮﻝ ﻗﻴﺎﺱ ﺍﻟﻌﻴﻨﺎﺕ ﺍﳌﺨﺘﻠﻔﺔ ﺍﳌﺨﺘﱪﺓ ) ﻋﻴﻨﺔ ﻣﻮﺣﺪﺓ ﻗﻴﺎﺳﻴﺔ( ﻟﺴﻬﻮﻟﺔ‬ ‫ﺍﳊﻜﻢ ﻋﻠﻰ ﻗﺒﻮﻝ ﺃﻭ ﺭﻓﺾ ﺍﳌﻌﺎﺩﻥ ﰱ ﺍﻷﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﻄﻠﻮﺑﺔ ﺃﻭ ﺍﳌﻘﺎﺭﻧﺔ ﺑﲔ ﺗﻠﻚ ﺍﳌﻌﺎﺩﻥ‪ .‬ﻭﳚـﺐ‬ ‫ﺃﻥ ﺗﻜﻮﻥ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺑﻌﺪ ﻛﺴﺮ ﺍﻟﻌﻴﻨﺔ ﺷﺎﻣﻠﺔ ﳌﻨﻄﻘﺔ ﺍﻟﺮﻗﺒﺔ ﺑﻜﺎﻣﻠﻬﺎ ‪ ،‬ﺃﻯ ﺃﻧﻪ ﳚﺐ ﺃﻥ ﻳﻜﻮﻥ ﻛﺴﺮ ﺍﻟﻌﻴﻨﺔ‬ ‫ﺗﻘﺮﻳﺒﺎ ﰱ ﺣﻮﺍﱃ ﻣﻨﺘﺼﻒ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ‪ .‬ﻟﺬﻟﻚ ﻧﺼﺖ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻋﻠﻰ ﺃﻥ ﺗﻜﻮﻥ ﻧﺘﺎﺋﺞ ﻗـﻴﻢ‬ ‫ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻼﺳﺘﻄﺎﻟﺔ ﺻﺤﻴﺤﺎ ﺇﺫﺍ ﻭﻗﻊ ﺍﻟﻜﺴﺮ ﰱ ﺍﻟﺜﻠﺚ ﺍﻷﻭﺳﻂ ﻟﻄﻮﻝ ﻗﻴﺎﺱ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻭﻳﻠﺰﻡ‬ ‫ﺇﳘﺎﻝ ﺗﻠﻚ ﺍﻟﻌﻴﻨﺔ ﻭﺇﻋﺎﺩﺓ ﺍﻻﺧﺘﺒﺎﺭ ﺛﺎﻧﻴﺔ ﻋﻠﻰ ﻋﻴﻨﺔ ﺃﺧﺮﻯ ﻟﻮ ﺣﺪﺙ ﺍﻟﻜﺴﺮ ﺧﺎﺭﺝ ﻣﻨﻄﻘﺔ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ‬ ‫ﺃﻭ ﻗﺮﺏ ﺇﺣﺪﻯ ‪‬ﺎﻳﱵ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻷﻥ ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻼﺳﺘﻄﺎﻟﺔ ﺗﻜﻮﻥ ﺻـﻐﲑﺓ ﻭﻻ ﺗﻌـﱪ ﺗﻌـﺒﲑﹰﺍ‬ ‫ﺻﺤﻴﺤﹰﺎ ﻋﻦ ﻣﺪﻯ ﳑﻄﻮﻟﻴﺔ ﺍﳌﻌﺪﻥ ﺍﳌﺨﺘﱪﺓ‪ .‬ﻛﻤﺎ ﺃﻥ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﻟﻜﻠﻴﺔ ﻟﻠﻌﻴﻨﺔ ﺑﻌﺪ ﺍﻟﻜﺴﺮ ﲢـﺖ ﺗـﺄﺛﲑ‬ ‫ﺃﲪﺎﻝ ﺍﻟﺸﺪ ﻋﺒﺎﺭﺓ ﻋﻦ ﳎﻤﻮﻉ ﻧﻮﻋﲔ ﻣﻦ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻭﻫﻰ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﻟﻌﺎﻣﺔ‪ ،‬ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﳌﻮﺿﻌﻴﺔ ﻭﻣﻦ‬ ‫ﻫﻨﺎ ﳚﺐ ﺩﺭﺍﺳﺔ ﺃﻣﺮﻳﻦ ﻣﻬﻤﲔ ﳘﺎ ﻣﻌﺎﺩﻟﺔ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﻟﻌﺎﻣﺔ ﻭﺍﻟﻌﻴﻨﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻷﻃـﻮﺍﻝ ﺍﻟﻘﻴـﺎﺱ ﰱ‬ ‫ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ‪٠‬‬ ‫‪@ @òÛbĐnüa@òÛ…bÈß MQ‬‬ ‫ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﻟﻌﺎﻣﺔ ﺗﺘﻮﻗﻒ ﻋﻠﻰ ﻗﻴﻤﺔ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻭﺗﺘﻨﺎﺳﺐ ﻃﺮﺩﻳﺎ ﻣﻌﻬﺎ‪.‬‬ ‫‪∆L1 = α.L‬‬

‫ﺣﻴﺚ‪:‬‬

‫‪ = L‬ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ‬

‫‪ = α‬ﻋﺪﺩ ﺛﺎﺑﺖ‪٠‬‬

‫‪،‬‬ ‫‪٥٠‬‬


‫ﻭﺗﺘﻮﻗﻒ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﳌﻮﺿﻌﻴﺔ ﻋﻠﻰ ﻣﺪﻯ ﺣﺪﻭﺙ ﺍﻟﺮﻗﺒﺔ ﺍﻟﱴ ﺗﺘﺴﺒﺐ ﰱ ﻫﺬﻩ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﻟـﱴ ﺗـﺰﺩﺍﺩ‬ ‫ﻗﻴﻤﺘﻬﺎ ﺑﻜﱪ ﺍﳌﺴﺎﺣﺔ ﺍﻷﺻﻠﻴﺔ ﻟﻠﻤﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻭﺃ‪‬ﺎ ﺃﻳﻀﺎ ﺗﺘﻨﺎﺳﺐ ﻃﺮﺩﻳﹰﺎ ﻣـﻊ ﺍﳉـﺬﺭ ﺍﻟﺘـﺮﺑﻴﻌﲕ‬ ‫ﻟﻠﻤﺴﺎﺣﺔ ﺍﻷﺻﻠﻴﺔ ﻟﻠﻤﻘﻄﻊ‪.‬‬ ‫‪∆L2 = β Ao‬‬

‫ﺣﻴﺚ‪:‬‬

‫‪ = Ao‬ﺍﳌﺴﺎﺣﺔ ﺍﻷﺻﻠﻴﺔ ﻟﻠﻤﻘﻄﻊ‬ ‫‪ = β‬ﻋﺪﺩ ﺛﺎﺑﺖ ﻭﺑﺬﻟﻚ ﺗﻜﻮﻥ ﻣﻌﺎﺩﻟﺔ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﻟﻜﻠﻴﺔ ﻛﻤﺎ ﻳﻠﻰ‬ ‫‪= αL + β Ao‬‬

‫‪∆L = ∆L1 + ∆L2‬‬

‫ﻭﺗﻜﻮﻥ ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻼﺳﺘﻄﺎﻟﺔ ﻛﻤﺎ ﻳﻠﻰ‬ ‫‪αL + β Ao‬‬ ‫‪∆L‬‬ ‫= ‪× 100‬‬ ‫‪× 100‬‬ ‫‪L‬‬ ‫‪L‬‬

‫= ‪Elongation %‬‬

‫ﺣﻴﺚ ‪ β ، α‬ﺛﻮﺍﺑﺖ ﺗﺴﻤﻰ ﺛﻮﺍﺑﺖ ﹸﺃﻧﻮﻳﻦ )‪ (Unwin’s Constants‬ﻭﳝﻜﻦ ﺗﻌـﻴﲔ ﻗﻴﻤﺘـﻬﻤﺎ‬ ‫ﻋﻤﻠﻴﹰﺎ ﺑﺮﺳﻢ ﺍﳌﻨﺤﲎ ﺍﻟﺒﻴﺎﱏ ﺑﲔ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﳌﻘﺎﺑﻠﺔ ﻟﻜﻞ ﻃﻮﻝ ﻗﻴﺎﺱ ﻟﻠﻌﻴﻨﺎﺕ ﺍﳌﺨﺘﱪﺓ ﻣﻊ‬ ‫ﺛﺒﻮﺕ ﺍﳌﻘﻄﻊ ﺍﻷﺻﻠﻰ ﻟﻜﻞ ﻣﻨﻬﺎ ﻭ ﺍﻟﺮﺳﻢ ﺍﳌﺒﲔ ﺑﺸﻜﻞ )‪ (١٩-٢‬ﻳﺼﻒ ﺍﳌﻌﺎﺩﻟﺔ ﺑﲔ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻭﻃﻮﻝ‬ ‫ﺍﻟﻘﻴﺎﺱ ﻭﻫﻰ‪∆L = β Ao + αL :‬‬

‫ﺣﻴﺚ )‪ (Ao, α , β‬ﺃﻋﺪﺍﺩ ﺛﺎﺑﺘﺔ‪.‬‬

‫ﻭﻳﺘﻀﺢ ﺃﻥ ﺍﳌﻌﺎﺩﻟﺔ ﳋﻂ ﻣﺴﺘﻘﻴﻢ ﺑﲔ ﻣﺘﻐﲑﻳﻦ )‪ ، (L) ، (∆L‬ﻭﺑﺬﻟﻚ ﳝﻜﻦ ﺗﻌﻴﲔ ﻗﻴﻤﺔ ﻛﻞ ﻣﻦ ‪α, β‬‬

‫ﻣﻦ ﻫﺬﺍ ﺍﻟﺮﺳﻢ ﺍﻟﺒﻴﺎﱏ ﺣﻴﺚ )‪ (α‬ﻫﻰ ﻣﻴﻞ ﺍﳋﻂ ﺍﳌﺴﺘﻘﻢ ‪ ،‬ﻭﻗﻴﻤﺔ‬

‫‪β Ao‬‬

‫ﻫﻲ ﻗﻴﻤﺔ ﺍﻟﻼﺳﺘﻄﺎﻟﺔ ﻋﻨﺪ‬

‫ﺗﻘﺎﻃﻊ ﺍﳋﻂ ﺍﳌﺴﺘﻘﻴﻢ ﻣﻊ ﳏﻮﺭ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻭﲟﻌﻠﻮﻣﻴﺔ )‪ (Ao‬ﳝﻜﻦ ﻣﻌﺮﻓﺔ )‪.(β‬‬

‫ ا‪ 7$‬ا;? = ‪α‬‬

‫‪β √Ao‬‬

‫∆( ‪Elongation‬‬ ‫ا‪∆L) /‬‬

‫‪∆L = β Ao + αL‬‬

‫<"ل ا;س )‪Gage Length (L‬‬

‫‘‪@ @@òÛbĐnüaë@÷bîÔÛa@Þì@í@òÓýÈÛa@óäzäß@@HQYMRI@ÝØ‬‬ ‫@@‬

‫‪٥١‬‬


‫‪@ @†’Ûa@‰bjnü@òîbîÔÛa@pbäîÈÛa MR‬‬ ‫ﻳﻼﺣﻆ ﻣﻦ ﻣﻌﺎﺩﻟﺔ ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻼﺳﺘﻄﺎﻟﺔ ﺃﻥ ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻼﺳﺘﻄﺎﻟﺔ ﺗﻜﻮﻥ ﺫﺍﺕ ﻗﻴﻤـﺔ ﺛﺎﺑﺘـﺔ ﺇﺫﺍ‬ ‫ﻛﺎﻧﺖ ﻗﻴﻤﺔ‬

‫‪Ao‬‬ ‫‪L‬‬

‫ﺫﺍﺕ ﻗﻴﻤﺔ ﺛﺎﺑﺘﺔ ﺃﻯ ﺃﻥ ﺍﳉﺬﺭ ﺍﻟﺘﺮﺑﻴﻌﻰ ﻟﻠﻤﺴﺎﺣﺔ ﻳﺘﻨﺎﺳﺐ ﻣﻊ ﻃـﻮﻝ ﺍﻟﻘﻴـﺎﺱ‪.‬‬

‫ﻭﺣﻴﺚ ﺃﻧﻪ ﰱ ﺍﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﺸﺪ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻳﻠﺰﻡ ﺃﻥ ﺗﻜﻮﻥ ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﻟﻼﺳﺘﻄﺎﻟﺔ ﺍﳌﻌﱪﺓ ﻋـﻦ ﳑﻄﻮﻟﻴـﺔ‬ ‫ﺍﳌﻌﺪﻥ ﺛﺎﺑﺘﺔ ﻣﻬﻤﺎ ﺗﻐﲑ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﻌﻴﻨﺔ ﻟﺬﻟﻚ ﻳﻠﺰﻡ ﰱ ﻫﺬﻩ ﺍﳊﺎﻟﺔ ﺃﻥ ﺗﻜﻮﻥ ﻋﻴﻨـﺔ ﺍﻻﺧﺘﺒـﺎﺭ‬ ‫ﺫﺍﺕ ﻃﻮﻝ ﻗﻴﺎﺱ ﻳﺘﻨﺎﺳﺐ ﻣﻊ ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ‪ .‬ﻭﺗﺴﻤﻰ ﻣﺜﻞ ﻫﺬﻩ ﺍﻟﻌﻴﻨﺎﺕ ﺑﻌﻴﻨﺎﺕ ﺍﻻﺧﺘﺒـﺎﺭ‬ ‫ﺍﳌﺘﻨﺎﺳﺒﺔ‪ ،‬ﻭﻗﺪ ﺣﺪﺩﺕ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﺍﻟﺜﺎﺑﺖ ﺍﻟﻼﺯﻡ ﳍﺬﺍ ﺍﻟﺘﻨﺎﺳﺐ ‪ ،‬ﻭﻗﺪ ﺍﻋﺘﱪﺕ ﺍﳌﻮﺍﺻـﻔﺎﺕ‬ ‫ﺍﻟﻘﻴﺎﺳﻴﺔ ﺍﳌﺼﺮﻳﺔ ﻻﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻟﻠﻤﻌﺎﺩﻥ ﺍﻟﻌﻼﻗﺔ ﺑﲔ ‪ Ao ، L‬ﻛﻤﺎ ﻳﻠﻲ‪:‬‬ ‫• ﺍﻟﻌﻴﻨﺎﺕ ﺍﻟﻘﺼﲑﺓ‬ ‫• ﺍﻟﻌﻴﻨﺎﺕ ﺍﻟﻄﻮﻳﻠﺔ‬

‫‪Ao‬‬ ‫‪Ao‬‬

‫‪L= 5.65‬‬ ‫‪L = 11.3‬‬

‫‪@ @@Z@µg@ñŠí†n½a@pbÇbĐÔÛa@pa‡@pbäîÈÛa@òÛby@óÏ@ô…ûí@ÙÛ‡ë‬‬

‫• ﺍﻟﻌﻴﻨﺎﺕ ﺍﻟﻘﺼﲑﺓ‬

‫‪L = 5 do‬‬

‫• ﺍﻟﻌﻴﻨﺎﺕ ﺍﳌﺘﻮﺳﻄﺔ‬

‫‪L = 5 do : 10 do‬‬

‫• ﺍﻟﻌﻴﻨﺎﺕ ﺍﻟﻄﻮﻳﻠﺔ‬

‫‪L = 10 do‬‬

‫‪٥٢‬‬


‫‪@ @(Poisson’s Ratio)@æìaìi@òjã@@QSMSMR‬‬ ‫ﻋﻨﺪﻣﺎ ﺗﺘﻌﺮﺽ ﻋﻴﻨﺔ ﻣﻌﺪﻧﻴﺔ ﻟﻘﻮﺓ ﺷﺪ ﳏﻮﺭﻳﺔ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺸﻜﻞ )‪ (٢٠-٢‬ﻓﺈﻧﻪ ﲢﺪﺙ ﺇﺳـﺘﻄﺎﻟﺔ‬ ‫ﰱ ﺇﲡﺎﻩ ﻗﻮﺓ ﺍﻟﺘﺤﻤﻴﻞ ﻭﻳﻘﺎﺑﻠﻬﺎ ﻧﻘﺺ ﰱ ﺍﻟﻌﺮﺽ ﰱ ﻛﻞ ﻣﻦ ﺍﻻﲡﺎﻫﲔ ﺍﳌﺘﻌﺎﻣﺪﻳﻦ ﻋﻠﻰ ﺍﲡﺎﻩ ﻗﻮﺓ ﺍﻟﺸﺪ‪.‬‬ ‫ﻓﺈﺫﺍ ﰎ ﺗﻌﻴﲔ ﻗﻴﻤﺔ ﺍﻻﻧﻔﻌﺎﻝ ﰱ ﺍﻻﲡﺎﻩ ﺍﻟﻄﻮﱄ ﺍﶈﻮﺭﻱ ﻭﻛﺬﻟﻚ ﻗﻴﻤﺔ ﺍﻻﻧﻔﻌﺎﻝ ﰱ ﺍﻻﲡﺎﻩ ﺍﻟﻌﺮﺿﻲ ﻓـﺈﻥ‬ ‫ﻧﺴﺒﺔ ﺑﻮﺍﺳﻮﻥ ﺗﻜﻮﻥ‪:‬‬ ‫ﻧﺴﺒﺔ ﺑﻮﺍﺳﻮﻥ )‪= (µ‬‬

‫‪εb‬‬

‫ﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻌﺮﺿﻰ‬

‫ﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻄﻮﱃ ‪εL‬‬ ‫‪L1 – L‬‬ ‫‪L‬‬

‫= ‪εL‬‬

‫‪b1 - b‬‬ ‫‪b‬‬

‫= ‪εb‬‬

‫ﻭﺗﻜﻮﻥ ﻧﺴﺒﺔ ﺑﻮﺍﺳﻮﻥ ﻗﻴﻤﺔ ﺛﺎﺑﺘﺔ ﺗﻌﺘﱪ ﺇﺣﺪﻯ ﺍﻟﺜﻮﺍﺑﺖ ﻟﻠﻤﻮﺍﺩ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧـﺔ ﻭﺗﺘـﺮﺍﻭﺡ ﻗﻴﻤﺘـﻬﺎ‬ ‫ﻷﻏﻠﺐ ﺍﳌﻮﺍﺩ ﺑﲔ ‪ ٠,٣٦ : ٠,٢٥‬ﻭﺗﻜﻮﻥ ﺣﻮﺍﱃ ‪ ٠,٢٩‬ﻟﻠﺤﺪﻳﺪ ﺍﻟﺼﻠﺐ‪ .‬ﻭﺗﻜـﻮﻥ ﻗﻴﻤـﺔ ﻧـﺴﺒﺔ‬ ‫ﺑﻮﺍﺳﻮﻥ ﰱ ﻣﻨﻄﻘﺔ ﺍﻟﻠﺪﻭﻧﺔ ﺛﺎﺑﺘﺔ ﺃﻳﻀﹰﺎ ﻭﺗﻜﻮﻥ ﻗﻴﻤﺘﻬﺎ ﳌﻌﻈﻢ ﺍﳌﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ‪ .٠,٥‬ﻭﳝﻜﻦ ﺗﻌـﻴﲔ ﻧـﺴﺒﺔ‬ ‫ﺑﻮﺍﺳﻮﻥ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﻣﻦ ﺍﻟﻌﻼﻗﺔ ﺍﻵﺗﻴﺔ‪:‬‬ ‫‪E‬‬

‫)‪2 (1+µ‬‬

‫• ‪ = E‬ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ‬ ‫• ‪ = G‬ﻣﻌﺎﻳﺮ ﺍﳉﺴﺎﺀﺓ‬ ‫• ‪ = µ‬ﻧﺴﺒﺔ ﺑﻮﺍﺳﻮﻥ‬

‫‪b‬‬

‫‪b1‬‬ ‫‪∆L‬‬

‫‪L‬‬

‫‪L1‬‬

‫‘‪@ @æìaìi@òjã@HRPMRI@ÝØ‬‬ ‫‪٥٣‬‬

‫=‪G‬‬


‫‪@ @@ô…bÈÛa@ÞbÈÐãüaë@…bèu⁄a@@QTMSMR‬‬ ‫ﳝﻜﻦ ﺗﻌﻴﲔ ﺍﻟﻘﻴﻢ ﺍﻟﻌﺎﺩﻳﺔ ﻟﻺﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﲟﻌﻠﻮﻣﻴﺔ ﻧﺘﺎﺋﺞ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﺍﻻﺳﺘﺎﺗﻴﻜﻰ ﻟﻠﺤﻤﻞ ﺍﳌـﺆﺛﺮ‬ ‫ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﳌﻘﺎﺑﻠﺔ ﻟﻪ ﺣﱴ ﺍﻟﻜﺴﺮ ﻛﻤﺎ ﻳﻠﻲ‪:‬‬ ‫ﺍﻹﺟﻬﺎﺩ ﺍﻟﻌﺎﺩﻯ ‪= σ‬‬

‫ﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻌﺎﺩﻯ ‪= ε‬‬

‫ﲪﻞ ﺍﻟﺸﺪ ﺍﶈﻮﺭﻯ )‪(P‬‬ ‫ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﻷﺻﻠﻴﺔ )‪(Ao‬‬ ‫ﺍﻻﺳﺘﻄﺎﻟﺔ )‪(∆L‬‬ ‫ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﺍﻷﺻﻠﻰ )‪(L o‬‬

‫ﻭﻧﻈﺮﹰﺍ ﻷﻥ ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﻷﺻﻠﻴﺔ )‪ (Ao‬ﻭﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﺍﻷﺻﻠﻰ )‪ (Lo‬ﻗﻴﻢ ﺛﺎﺑﺘـﺔ ﻓـﺈﻥ ﻣـﻨﺤﲎ‬ ‫ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻌﺎﺩﻯ ﻳﻜﻮﻥ ﻟﻪ ﺷﻜﻞ ﳝﺎﺛﻞ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﺳﺘﻄﺎﻟﺔ ﺍﻟﺴﺎﺑﻖ ﺍﻹﺷﺎﺭﺓ ﺇﻟﻴﺔ ﻛﻤـﺎ‬ ‫ﻳﺘﻀﺢ ﻣﻦ ﺷﻜﻞ )‪ .(٢١-٢‬ﻭﻳﺴﺘﺨﺪﻡ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻌﺎﺩﻱ ﰱ ﺗﻌﻴﲔ ﻣﻌﻈﻢ ﺍﳋـﻮﺍﺹ‬ ‫ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻠﻤﻌﺎﺩﻥ ﲢﺖ ﺗﺄﺛﲑ ﺃﲪﺎﻝ ﺍﻟﺸﺪ‪.‬‬

‫; او ‬ ‫‪Plastic State‬‬

‫ا‪%&,‬د‬

‫;و ا‬

‫ا&‪%‬د ا‪"#$‬ع‬ ‫ ا‬ ‫; او ا ‬ ‫‪Elastic-Plastic State‬‬

‫; او ‬ ‫‪Elastic State‬‬

‫ا‪./‬ل‬

‫‘‪@ @ÝîĐß@æ†È½@ô…bÈÛa@ÞbÈÐãüaë@…bèu⁄a@óäzäß@HRQMRI@ÝØ‬‬

‫‪٥٤‬‬


‫‪@ @óÔîÔ§a@ÞbÈÐãüa@…bèu⁄a@óäzäß@@QUMSMR‬‬ ‫ﻣﻦ ﺩﺭﺍﺳﺘﻨﺎ ﻟﺘﻌﻴﲔ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻌﺎﺩﻱ ﻭﺟﺪﻧﺎ ﺃﻥ ﻗﻴﻢ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻟﻴـﺴﺖ ﺩﻗﻴﻘـﺔ ﰱ‬ ‫ﺍﳌﻨﻄﻘﺔ ﺍﻟﱴ ﺗﻔﻮﻕ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﺃﻯ ﻣﻦ ﻣﻨﻄﻘﺔ ﺍﳋﻀﻮﻉ ﻭﺣﱴ ﺍﻟﻜﺴﺮ ﻭﺫﻟﻚ ﻧﺘﻴﺠﺔ ﺃﻥ ﺍﻹﺟﻬﺎﺩ ‪ð…@ b;ÈÛa‬‬

‫ﻫﻮ ﻋﺒﺎﺭﺓ ﻋﻦ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﰱ ﺍﻟﺸﺪ )‪ (P‬ﻣﻘﺴﻮﻣﺎ ﻋﻠﻰ ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﻷﺻﻠﻴﺔ )‪ (Ao‬ﻭﻟﻜﻦ ﺍﻹﺟﻬﺎﺩ‬ ‫‪ ó@ ;ÔîÔ§a‬ﺍﻟﱴ ﺗﻘﺎﻭﻣﺔ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﰱ ﺍﻟﺸﺪ ﻫﻮ ﻋﺒﺎﺭﺓ ﻋﻦ ﺍﳊﻤﻞ )‪ (P‬ﻣﻘﺴﻮﻣﺎ ﻋﻠﻰ ﻣـﺴﺎﺣﺔ ﺃﻗـﻞ‬ ‫ﻣﻘﻄﻊ ﺳﻴﺘﻌﺮﺽ ﻟﻠﻌﻴﻨﺔ ﻋﻨﺪ ﺫﻟﻚ ﺍﳊﻤﻞ‪ .‬ﻧﻈﺮﹰﺍ ﻷﻥ ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﻓﻮﻕ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﺃﻗﻞ ﻣﻨﻬﺎ ﻟﻠﻤﻘﻄﻊ‬ ‫ﺍﻷﺻﻠﻰ ﻭﺗﻨﻘﺺ ﺑﻮﺿﻮﺡ ﻋﻨﺪ ﺣﺪﻭﺙ ﺍﻟﺮﻗﺒﺔ ﻭﺗﺴﺘﻤﺮ ﺗﻠﻚ ﺍﻟﺰﻳﺎﺩﺓ ﰱ ﺍﻟﻨﻘﺼﺎﻥ ﺣﱴ ﻛـﺴﺮ ﺍﻟﻌﻴﻨـﺔ‬ ‫ﻟﺬﻟﻚ ﻓﺈﻥ ﺍﻹﺟﻬﺎﺩ ‪ óÔîÔ§a‬ﻳﻜﻮﻥ ﰱ ﺍﻟﻮﺍﻗﻊ ﺃﻛﱪ ﻣﻦ ﺍﻹﺟﻬﺎﺩ ‪ ô…bÈÛa‬ﳑﺎ ﻳﻔﻴـﺪ ﰱ ﻣﻌﺮﻓـﺔ ﺍﳌﻘﺎﻭﻣـﺔ‬ ‫ﺍﳊﻘﻴﻘﺔ ﻟﻠﻤﻌﺎﺩﻥ ﺍﳌﺨﺘﱪﺓ‪٠‬‬ ‫ﺍﻹﺟﻬﺎﺩ ﺍﳊﻘﻴﻘﻰ ‪= σ t‬‬

‫ﺍﳊﻤﻞ ﰱ ﺃﻯ ﳊﻈﺔ )‪(Pi‬‬ ‫ﻣﺴﺎﺣﺔ ﺃﻗﻞ ﻣﻘﻄﻊ ﻋﻨﺪ ﺗﻠﻚ ﺍﻟﻠﺤﻈﺔ )‪(Ai‬‬

‫ﻛﺬﻟﻚ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻼﻧﻔﻌﺎﻝ ﺍﻟﻌﺎﺩﻱ ﻓﻬﻮ ﻋﺒﺎﺭﺓ ﻋﻦ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻣﻨﺴﻮﺑﺔ ﺇﱃ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﺑﻴﻨﻤﺎ ﰱ ﺍﻟﻮﺍﻗـﻊ‬ ‫ﻓﺈﻧﻪ ﻋﻨﺪ ﺍﻟﺘﺤﻤﻴﻞ ﰱ ﺍﻟﺸﺪ ﻓﺈﻥ ﻛﻞ ﺯﻳﺎﺩﺓ ﰱ ﺍﳊﻤﻞ ﺗﺴﺒﺐ ﺍﺳﺘﻄﺎﻟﺔ ﻓﻴﻜﻮﻥ ﺍﻻﻧﻔﻌﺎﻝ ﺍﳊﻘﻴﻘﻲ ﻋﻨﺪ ﺃﻯ‬ ‫ﲪﻞ ﻫﻮ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻋﻨﺪ ﻫﺬﺍ ﺍﳊﻤﻞ ﻣﻨﺴﻮﺑﺔ ﺇﱃ ﺍﳌﺴﺎﻓﺔ ﺑﲔ ‪‬ﺎﻳﱴ ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ ﻋﻨﺪ ﺍﳊﻤـﻞ ﺍﻟـﺴﺎﺑﻖ‬ ‫ﻣﺒﺎﺷﺮﺓ ﺃﻯ ﺃﻥ ﺍﻻﻧﻔﻌﺎﻝ ﺍﳊﻘﻴﻘﻲ ﻋﻨﺪ ﺃﻯ ﲪﻞ ﻫﻮ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻣﻨﺴﻮﺑﺔ ﺇﱃ ﻃﻮﻝ ﳜﺘﻠﻒ ﰱ ﻗﻴﻤﺘـﻪ ﻋـﻦ‬ ‫ﻣﺜﻴﻠﻪ ﻋﻨﺪ ﺣﺴﺎﺏ ﺍﻻﻧﻔﻌﺎﻝ ﰱ ﺍﻷﲪﺎﻝ ﺍﻷﺧﺮﻯ ﺳﻮﺍﺀ ﺍﻟﺴﺎﺑﻘﺔ ﻟﻪ ﺃﻭ ﺍﻟﱴ ﺗﻠﻴﻪ ﻭﺫﻟﻚ ﺃﻳﻀﺎ ﻓﻮﻕ ﺣـﺪ‬ ‫ﺍﳌﺮﻭﻧﺔ ﺣﻴﺚ ﺗﻜﻮﻥ ﺍﻻﺳﺘﻄﺎﻟﺔ ﺫﺍﺕ ﺷﻜﻞ ﻣﻠﺤﻮﻅ‪.‬‬ ‫ﻋﻨﺪ ﺭﺳﻢ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﺍﳊﻘﻴﻘﻰ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺍﳊﻘﻴﻘﻰ ﻟﻌﻴﻨﺔ ﻣﻦ ﻣﻌﺪﻥ ﻣﻄﻴﻞ ﻓﺈﻧﻪ ﻳﻜﻮﻥ ﻋﺒﺎﺭﺓ ﻋﻦ ﻋﻼﻗﺔ‬ ‫ﺃﺳﻴﺔ )‪ (σ = b εc‬ﰱ ﺍﳌﻨﻄﻘﺔ ﻣﻦ ﺍﳋﻀﻮﻉ ﺣﱴ ﺣﺪﻭﺙ ﺍﻟﺮﻗﺒﺔ ﻭﺫﻟﻚ ﺑﺎﻧﻔﻌﺎﻝ ﺣﻘﻴﻘﻲ ﻋﻨـﺪ ﺍﳋـﻀﻮﻉ‬ ‫ﻳﺴﺎﻭﻯ ﺻﻔﺮﹰﺍ ﺗﻘﺮﻳﺒﹰﺎ ﻷﻥ ‪ do = di‬ﺗﻘﺮﻳﺒﺎ ﻋﻨﺪ ﺍﳋﻀﻮﻉ ﻓﻴﻜﻮﻥ ﺍﻻﻧﻔﻌﺎﻝ ﺻﻔﺮ‪ ،‬ﻭﺑﺈﺟﻬﺎﺩ ﺣﻘﻴﻘﻰ ﻋﻨﺪ‬ ‫ﺍﳋﻀﻮﻉ ﻳﺴﺎﻭﻯ ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﺍﻟﻌﺎﺩﻱ ﻷﻥ ﺍﻟﺘﻐﲑ ﰱ ﺍﻟﺸﻜﻞ ﻟﻠﻤﻘﻄﻊ ﻋﻨﺪ ‪‬ﺎﻳﺔ ﻣﺮﺣﻠﺔ ﺍﳌﺮﻭﻧﺔ ﺻـﻐﲑ‬ ‫ﺟﺪﹰﺍ ﻭﺗﻌﺘﱪ ﻗﻴﻤﺘﻪ ﻣﻌﺪﻭﻣﺔ ﳝﻜﻦ ﺇﳘﺎﳍﺎ‪ .‬ﺃﻣﺎ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﻤﻨﻄﻘﺔ ﻣﻦ ﺣﺪﻭﺙ ﺍﻟﺮﻗﺒﺔ ﺣﱴ ﺍﻟﻜﺴﺮ ﻓﺈﻥ ﺍﳌﻨﺤﲎ‬ ‫ﻳﻜﻮﻥ ﻋﺒﺎﺭﺓ ﻋﻦ ﺧﻂ ﻣﺴﺘﻘﻴﻢ )‪ (σ = k ε+m‬ﻛﻤﺎ ﻳﺘﻀﺢ ﻣﻦ ﺍﻟﺸﻜﻞ )‪.(٢٢-٢‬‬

‫‪٥٥‬‬


‫ﺍﻟﻨﻘﻄﺔ ﺍﳌﻨﺎﻇﺮﺓ‬ ‫ﳊﻤﻞ ﺍﻟﻜﺴﺮ‬

‫‪A‬‬

‫ا‪%&,‬د ا*;;‪5‬‬

‫‪B‬‬

‫ﺍﻟﻨﻘﻄﺔ ﺍﳌﻨﺎﻇﺮﺓ‬ ‫ﻷﻗﺼﻰ ﲪﻞ‬

‫ا‪./‬ل ا*;;‪5‬‬

‫‘‪@ @ÝîĐß@æ†È½@óÔîÔ§a@ÞbÈÐãüaë@…bèu⁄a@óäzäß@HRRMRI@ÝØ‬‬ ‫‪@ @NïÔîÔ§a@ÞbÈÐãüaë@…bèu⁄a@óäzäß@ë@ô…bÈÛa@ÞbÈÐãüaë@…bèu⁄a@ózäß@í@ÖŠÐÛa@|™ìí@ïmŁa@Þë†¦aë‬‬ ‫‪< '(8 9: $;$‬‬

‫‪7 '(8 9: $;$‬‬

‫• ﻗﻴﻢ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺻـﺤﻴﺤﺔ ﰱ ﺣـﺪﻭﺩ • ﻗﻴﻢ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺣﻘﻴﻘﻴﺔ ﻭﺻﺤﻴﺤﺔ ﻓﻮﻕ‬ ‫ﺣﺪ ﺍﳌﺮﻭﻧﺔ‪.‬‬

‫ﺍﳌﺮﻭﻧﺔ ﻭﻓﻮﻕ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﺗﻌﻄﻰ ﻗﻴﻤﹰﺎ ﻟﻠﻤﻘﺎﺭﻧﺔ‬ ‫ﺑﲔ ﺍﳌﻌﺎﺩﻥ‬ ‫• ﻳﻔﻴﺪ ﰱ ﺃﻋﻤﺎﻝ ﺍﻟﺘﺼﻤﻴﻢ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ‪.‬‬

‫• ﻳﻔﻴﺪ ﰱ ﺃﻋﻤﺎﻝ ﺍﻟﺘﺼﻤﻴﻢ ﻓﻮﻕ ﺣﺪ ﺍﳌﺮﻭﻧﺔ‪.‬‬

‫• ﻳﺘﻢ ﺗﺼﻤﻴﻢ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻠﻤﻌـﺎﺩﻥ ﰱ • ﺗﻔﻴﺪ ﰱ ﺗﻌﻴﲔ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻠﻤﻌـﺎﺩﻥ‬ ‫ﺑﻘﻴﻢ ﺻﺤﻴﺤﺔ ﻭﺣﻘﻴﻘﻴﺔ ﻓﻮﻕ ﺣﺪ ﺍﳌﺮﻭﻧﺔ‪.‬‬

‫ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﺑﺪﻗﺔ ﻋﺎﻟﻴﺔ ﻭﺑﻄﺮﻳﻘﺔ ﺗﻘﺮﻳﺒﻴﺔ ﻓﻮﻕ‬ ‫ﺣﺪ ﺍﳌﺮﻭﻧﺔ‪.‬‬

‫• ﺍﳌﻨﺤﲎ ﻟﻴﺲ ﺣﺴﺎﺱ ﻓﻮﻕ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﻭﻟﻜـﻦ • ﺍﳌﻨﺤﲎ ﺣﺴﺎﺱ ﺟﺪﹰﺍ ﻓﻮﻕ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﻷﻯ ﺗﻐﲑ‬ ‫ﻳﺴﺘﺨﺪﻡ ﻓﻘﻂ ﻟﺪﺭﺍﺳﺔ ﺍﳋـﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴـﺔ‬

‫ﰱ ﻇﺮﻭﻑ ﺍﳌﺎﺩﺓ ﺳـﻮﺍﺀ ﻛﺎﻧـﺖ ﻓﻠﺰﻳـﺔ ﺃﻭ‬

‫ﻟﻠﻤﻘﺎﺭﻧﺔ ﺑﲔ ﺍﳌﻮﺍﺩ ﺍﳌﺨﺘﻠﻔﺔ‬

‫ﻣﻴﻜﺎﻧﻴﻜﻴﺔ‪.‬‬

‫• ﻳﺴﺘﻔﺎﺩ ﻣﻨﻪ ﰱ ﺃﻋﻤﺎﻝ ﺍﻟﺘﺸﻐﻴﻞ ﻟﻠﻤﻌـﺎﺩﻥ ﰱ • ﻳﺴﺘﻔﺎﺩ ﻣﻨﻬﺎ ﰱ ﺃﻋﻤـﺎﻝ ﺍﻟﺘـﺸﻜﻴﻞ ﺍﻟﻠﺪﻧـﺔ‬ ‫ﻟﻠﻤﻌﺎﺩﻥ ﻣﺜﻞ ﺍﻟﺪﻟﻔﻨﺔ ﻭﺍﻟﺴﺤﺐ ﻭﺍﻟﻄﺮﻕ‪.‬‬

‫ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ‪.‬‬

‫• ﻣﻦ ﺍﻟﻨﺎﺣﻴﺔ ﺍﻟﻌﻤﻠﻴﺔ ﻳﻜﻮﻥ ﻫﺬﺍ ﺍﳌﻨﺤﲎ ﺃﺳـﻬﻞ • ﻫﺬﺍ ﺍﳌﻨﺤﲎ ﳛﺘﺎﺝ ﺇﱃ ﺩﻗﺔ ﻋﺎﻟﻴـﺔ ﰱ ﺗﻮﻗﻴﻌـﻪ‬ ‫ﻭﺭﲰﺔ ﻟﺬﻟﻚ ﻳﺼﻌﺐ ﺇﻋﺪﺍﺩﻩ ﺃﺛﻨﺎﺀ ﺍﻻﺧﺘﻴﺎﺭ‪.‬‬

‫ﰱ ﺍﻟﺘﻮﻗﻴﻊ ﺃﺛﻨﺎﺀ ﺍﻻﺧﺘﺒﺎﺭ ﻭﳝﻜﻦ ﺍﳊﺼﻮﻝ ﻋﻠﻴﺔ‬ ‫ﺑﺴﻬﻮﻟﺔ‪.‬‬

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‫‪, # .> 1 ?@ A B 4-2‬‬

‫ﺗﻮﺟﺪ ﻋﻮﺍﻣﻞ ﻋﺪﻳﺪﺓ ﺗﺆﺛﺮ ﻋﻠﻰ ﺧﻮﺍﺹ ﺍﳌﻌﺪﻥ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﰱ ﺇﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻣﻨﻬﺎ ﻣﺎ ﻳﻠﻲ‪:‬‬ ‫‪@ @@†öaŒÛa@ÞbÈÐãüa@MQ‬‬ ‫ﻋﻨﺪﻣﺎ ﲢﻤﻴﻞ ﻋﻴﻨﺔ ﰱ ﺍﻟﺸﺪ ﻓﻮﻕ ﺍﳌﺮﻭﻧﺔ ﰒ ﺃﺯﻳﻞ ﺍﳊﻤﻞ ﰒ ﺃﻋﻴﺪ ﺍﻟﺘﺤﻤﻴﻞ ﺛﺎﻧﻴﺔ ﺑﻌﺪ ﻓﺘﺮﺓ ﻳﻼﺣﻆ ﺃﻥ ﺣﺪ‬ ‫ﺍﻟﺘﻨﺎﺳﺐ ﺗﺰﻳﺪ ﻗﻴﻤﺘﻪ ﻛﻤﺎ ﺗﺰﻳﺪ ﺃﻳﻀﺎ ﻗﻴﻤﺔ ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﻋﻦ ﺣﺎﻟﺔ ﺍﻟﺘﺤﻤﻴﻞ ﺍﻷﻭﱃ ﺃﻯ ﺃﻧﻪ ﻗﺪ ﻧﺘﺠﺖ‬ ‫ﺯﻳﺎﺩﺓ ﰱ ﲢﻤﻞ ﺍﳌﻌﺪﻥ ﰱ ﻣﻨﻄﻘﺔ ﺍﳌﺮﻭﻧﺔ ﻭﺗﺴﻤﻰ ﻫﺬﻩ ﺍﳊﺎﻟﺔ ﺑﺎﻻﻧﻔﻌﺎﻝ ﺍﻟﺰﺍﺋﺪ‪ .‬ﻭﺗﺴﺎﻫﻢ ﻇﺎﻫﺮﺓ ﺍﻻﻧﻔﻌﺎﻝ‬ ‫ﺍﻟﺰﺍﺋﺪﺓ ﰱ ﲢﺴﲔ ﻇﺮﻭﻑ ﺍﻹﺟﻬﺎﺩﺍﺕ ﰱ ﺍﻷﺟﺰﺍﺀ ﺍﻹﻧﺸﺎﺋﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ ﻣﺜـﻞ ﺍﻟـﺴﻼﺳﻞ ﻭﺍﻟﻜـﺎﺑﻼﺕ‬ ‫ﻭﺍﳌﻮﺍﺳﲑ ﺍﻟﱵ ﻳﺘﻢ ﺗﻌﺮﻳﻀﻬﺎ ﺇﱃ ‪ æ@ bàš;Ûa@Þb»c‬ﰒ ﻳﺘﻢ ﺭﻓﻊ ﺍﻟﺘﺤﻤﻴﻞ ﻭﺫﻟﻚ ﺑﻌﺪ ‪‬ﺎﻳﺔ ﺍﻟﺘـﺼﻨﻴﻊ ﻭﻗﺒـﻞ‬ ‫ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﻟﺘﺤﺴﲔ ﺍﳌﺮﻭﻧﺔ‪.‬‬ ‫‪@ @@…‰bjÛa@óÜÇ@ÝîÌ’nÛa@MR‬‬ ‫ﺍﻟﺘﺸﻐﻴﻞ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻫﻮ ‪@òãëŠ½a@†y@ÖìÏ@æ†È½a@Ýîà¤‬ﰒ ﺇﻋﺎﺩﺓ ﲢﻤﻴﻠﺔ ﻣﺮﺓ ﺃﻭ ﻣﺮﺍﺕ ﻭﻳﻌﺘﱪ ﻣﻦ ﺣﺎﻻﺕ‬ ‫ﺍﻹﻧﻔﻌﺎﻝ ﺍﻟﺰﺍﺋﺪ ﻭﻳﻨﺘﺞ ﻋﻨﻪ ﲢﺴﲔ ﰱ ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﻭﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻭﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﺑﺎﻟﺰﻳﺎﺩﺓ ﻭﻳﺼﺎﺣﺒﻪ‬ ‫ﻧﻘﺺ ﰱ ﻗﻴﻤﺔ ﺍﳌﻤﻄﻮﻟﻴﺔ‪ ،‬ﻭﻳﺴﺒﺐ ﺃﻳﻀﹰﺎ ﺯﻳﺎﺩﺓ ﺧﻮﺍﺹ ﺍﻟﺼﻼﺩﺓ ﻭﺍﻟﺮﺟﻮﻋﻴﺔ ﻭﺗﻔﻴﺪ ﺣـﺎﻻﺕ ﺍﻟﺘـﺸﻐﻴﻞ‬ ‫ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﰱ ﲢﺴﲔ ﺧﻮﺍﺹ ﺍﻟﺸﺪ ﻟﻠﻜﺒﻼﺕ ﻭﺍﻟﻴﺎﻳﺎﺕ‪.‬‬ ‫‪@ @@æ†È½bi@æìiŠØÛa@ôìnª@MS‬‬ ‫ﺗﺘﺄﺛﺮ ﺧﻮﺍﺹ ﺍﻟﺸﺪ ﰱ ﺍﳌﻌﺎﺩﻥ ﺑﺎﻟﺰﻳﺎﺩﺓ ﺃﻭ ﺑﺎﻟﻨﻘﺺ ﺑﺼﻮﺭﺓ ﻣﻠﺤﻮﻇﺔ ﺗﺒﻌﺎ ﻟﺘﻐﲑ ﳏﺘﻮﻯ ﺍﻟﻜﺮﻳﻮﻥ ﺑﺎﳌﻌﺎﺩﻥ‪،‬‬ ‫ﺣﻴﺚ ﺃﻥ ﺯﻳﺎﺩﺓ ﺍﻟﻜﺮﺑﻮﻥ ﺗﺆﺩﻯ ﺇﱃ ﺯﻳﺎﺩﺓ ﰱ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻭﺍﳋﻀﻮﻉ ﻭﺇﺟﻬﺎﺩ ﺍﻟﺸﺪ ﻭﺗﺴﺒﺐ ﰱ ﻧﻘﺺ‬ ‫ﺍﳌﻤﻄﻮﻟﻴﺔ ﻭﺍﻟﻌﻜﺲ ﺻﺤﻴﺢ‪.‬‬ ‫‪@ @@ñ‰aŠ§a@òu‰…@MT‬‬ ‫ﺇﺫﺍ ﺍﺭﺗﻔﻌﺖ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﳌﻌﺎﺩﻥ ﻋﻦ ‪ ٢٥٠‬ﺩﺭﺟﺔ ﻣﺌﻮﻳﺔ ﻓﺈﻥ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻭﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﺗﻘﻞ ﺑﻴﻨﻤـﺎ‬ ‫ﺗﺰﺩﺍﺩ ﺍﳌﻤﻄﻮﻟﻴﺔ ﻟﻠﻤﻌﺎﺩﻥ ﺣﻴﺚ ﺃﻥ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﺗﺘﻨﺎﺳﺐ ﻋﻜﺴﻴﺎ ﻣﻊ ﺍﳊﺮﺍﺭﺓ ﺑﻴﻨﻤﺎ ﺍﳌﻤﻄﻮﻟﻴﺔ ﺗﺘﻨﺎﺳﺐ‬ ‫ﺗﻨﺎﺳﺒﹰﺎ ﻃﺮﺩﻳﹰﺎ ﻣﻌﻬﺎ‪.‬‬

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‫‪@ @‰bjnüa@õbäqc@ÝîàznÛa@òÇŠ@MU‬‬ ‫ﺇﻥ ﺳﺮﻋﺔ ﺍﻟﺘﺤﻤﻴﻞ ﺗﺆﺛﺮ ﺗﺄﺛﲑﹰﺍ ﻇﺎﻫﺮﹰﺍ ﻋﻠﻰ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﺣﻴﺚ ﺃﻥ ﺯﻳﺎﺩﺓ ﺍﻟﺴﺮﻋﺔ ﻳﻜـﻮﻥ ﻣـﺼﺤﻮﺑﺎ‬ ‫ﺑﺰﻳﺎﺩﺓ ﰱ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻭﻧﻘﺺ ﰱ ﺍﳌﻤﻄﻮﻟﻴﺔ ﺃﻣﺎ ﺍﳌﻌﺎﺩﻥ ﺍﻟﻘﺼﻔﺔ ﻓﻼ ﺗﺘﺄﺛﺮ ﻛﺜﲑﹰﺍ ﺑﺴﺮﻋﺔ ﺍﻟﺘﺤﻤﻴﻞ‪.‬‬ ‫‪@ @òîÛbÈÛa@ñ‰aŠ§a@pbu‰…@óÏ@ÝîàznÛa@ñ†ß@MV‬‬ ‫ﺗﺴﺒﺐ ﻣﺪﺓ ﺍﻟﺘﺤﻤﻴﻞ ﰱ ﺩﺭﺟﺎﺕ ﺍﳊﺮﺍﺭﺓ ﺍﻟﻌﺎﻟﻴﺔ ﻧﻘﺼﹰﺎ ﻭﺍﺿﺤﹰﺎ ﰱ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻟﻠﻤﻌﺎﺩﻥ‪.‬‬ ‫‪@ @òí‰aŠ§a@pýßbÈ½a@MW‬‬ ‫ﻭﺍﻟﱴ ﺗﺄﺧﺬ ﺻﻮﺭﹰﺍ ﻣﺘﻌﺪﺩﺓ ﻣﻨﻬﺎ‪:‬‬ ‫• ﺍﻟﺘﺨﻤﲑ ﻭﺍﳌﺮﺍﺟﻌﺔ‪ :‬ﻭﺍﻟﱴ ﲢﺴﻦ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻭﺍﳋﻀﻮﻉ ﻭﺍﳌﻤﻄﻮﻟﻴﺔ ﺣﻴﺚ ﺃ‪‬ﺎ ﺗﺰﻳﻞ ﺍﻻﺟﻬـﺎﺩﺍﺕ‬ ‫ﺍﳌﺘﺨﻠﻔﺔ ﻣﻦ ﺩﺍﺧﻞ ﺍﳌﻌﺪﻥ‪.‬‬ ‫• ﺍﻟﺘﺴﻘﻴﺔ ‪ :‬ﺗﺰﻳﺪ ﻣﻦ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻭﻟﻜﻨﻬﺎ ﺗﻘﻠﻞ ﺍﳌﻤﻄﻮﻟﻴﺔ‪.‬‬ ‫• ﺍﻟﺘﻄﺒﻴﻊ ‪ :‬ﲢﺴﻦ ﻛﺜﲑﹰﺍ ﻣﻦ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻭﺍﳌﻤﻄﻮﻟﻴﺔ‪.‬‬ ‫‪@ @xbnã⁄a@ÖŠ@MX‬‬ ‫ﻼ ﺗﺸﻜﻴﻞ ﺍﳌﻌﺪﻥ ﺑﺎﻟﺪﻟﻔﻨﺔ ﺃﻭ ﺍﻟﺴﺤﺐ‬ ‫ﺗﺆﺛﺮ ﻃﺮﻳﻘﺔ ﺍﻻﻧﺘﺎﺝ ﺗﺄﺛﲑﹰﺍ ﻫﺎﻣﹰﺎ ﻋﻠﻰ ﺧﻮﺍﺹ ﺍﳌﻌﺪﻥ ﰱ ﺍﻟﺸﺪ ﻓﻤﺜ ﹰ‬ ‫ﻋﻠﻰ ﺍﻟﺴﺎﺧﻦ ﲡﻌﻞ ﺧﻮﺍﺻﻪ ﳐﺘﻠﻔﺔ ﲤﺎﻣﺎ ﻋﻦ ﺣﺎﻟﺔ ﺗﺸﻜﻴﻠﻪ ﺑﺎﻟﺪﻟﻔﻨﺔ ﺃﻭ ﺍﻟﺴﺤﺐ ﻋﻠﻰ ﺍﻟﺒـﺎﺭﺩ ﺣﻴـﺚ‬ ‫ﺗﺰﺩﺍﺩ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻭﺍﻟﺮﺟﻮﻋﻴﺔ ﻭﺍﻟﺼﻼﺩﺓ ﻭﺗﻘﻞ ﺍﳌﻤﻄﻮﻟﻴﺔ ﻋﻨﺪ ﺍﻟﺘﺸﻜﻴﻞ ﻋﻠﻰ ﺍﻟﺒـﺎﺭﺩ ﻋﻨـﻬﺎ ﻋـﻦ‬ ‫ﺍﻟﺘﺸﻜﻴﻞ ﻋﻠﻰ ﺍﻟﺴﺎﺧﻦ‪.‬‬ ‫‪@ @ÙöbjÛa@óÏ@óÜ•þa@æ†ÈàÜÛ@pbÏb™⁄a@òjã@MY‬‬ ‫ﺣﻴﺚ ﺃﻧﻪ ﺇﺫﺍ ﹸﺃﺿﻴﻒ ﻣﻌﺪﻥ ﺃﻭ ﻣﻌﺎﺩﻥ ﺇﱃ ﺍﳌﻌﺪﻥ ﺍﻷﺻﻠﻲ ﻟﺘﻜﻮﻳﻦ ﺳﺒﻴﻜﺔ ﺟﺪﻳﺪﺓ ﻓـﺈﻥ ﺧﻮﺍﺻـﻬﺎ ﰱ‬ ‫ﺍﻟﺸﺪ ﲣﺘﻠﻒ ﲤﺎﻣﺎ ﻋﻦ ﺍﳌﻌﺪﻥ ﺍﻷﺻﻠﻲ‪.‬‬ ‫‪@ @‰bjnüa@òäîÇ@ÉĐÔß@ÝØ‘@MQP‬‬ ‫ﻳﺆﺛﺮ ﺷﻜﻞ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻠﻰ ﺧﻮﺍﺹ ﺍﻟﺸﺪ ﰱ ﺍﳌﻌﺎﺩﻥ ﺣﻴﺚ ﲣﺘﻠﻒ ﺍﻟﻨﺘﺎﺋﺞ ﻃﺒﻘﺎ ﻻﺧـﺘﻼﻑ ﺷـﻜﻞ‬ ‫ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ‪ .‬ﻭﻛﺬﻟﻚ ﺍﺧﺘﻼﻑ ﺷﻜﻞ ﻣﻘﻄﻊ ﻋﻴﻨﺔ ﺍﻻﺧﺘﻴﺎﺭ ﻣﻊ ﺗﺴﺎﻭﻯ ﻣﺴﺎﺣﺘﻪ ﰱ ﻛﻞ ﺣﺎﻟـﺔ ﻓـﺈﻥ‬ ‫ﺧﻮﺍﺹ ﺍﻟﺸﺪ ﺗﺘﺄﺛﺮ ﻭﲣﺘﻠﻒ ﻣﻦ ﻋﻴﻨﺔ ﻷﺧﺮﻯ ﻟﻠﻤﻌﺪﻥ ﺍﻟﻮﺍﺣﺪ ﺣﻴﺚ ﻳﻌﻄﻰ ﺍﳌﻘﻄﻊ ﺍﳌـﺴﺘﺪﻳﺮ ﻣﻘﺎﻭﻣـﺔ‬ ‫ﺃﻛﱪ ﻣﻦ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻄﻴﻞ‪.‬‬ ‫‪٥٨‬‬


‫‪@ @†’ÜÛ@òîÇìäÛa@òßëbÔ½a@MQQ‬‬ ‫ﻳﻠﺰﻡ ﻋﻨﺪ ﺗﺼﻤﻴﻢ ﺍﳌﻨﺸﺂﺕ ﻭﺍﳌﺎﻛﻴﻨﺎﺕ ﺃﻥ ﺗﺘﻮﺍﻓﺮ ﰱ ﺍﳌﻌﺎﺩﻥ ﺍﳌﺴﺘﺨﺪﻣﺔ ﺃﻥ ﺗﻜﻮﻥ ﳍﺎ ﻣﻘﺎﻭﻣﺔ ﻣﻨﺎﺳـﺒﺔ‬ ‫ﻣﺼﺤﻮﺑﺔ ﲞﻔﺔ ﺍﻟﻮﺯﻥ‪ ،‬ﻭﻣﻦ ﺍﻷﻣﺜﻠﺔ ﺍﳌﻬﻤﺔ ﰱ ﺫﻟﻚ ﺃﻋﻤﺎﻝ ﺍﻟﻄﻴﺎﺭﺍﺕ‪ ،‬ﻭﻟﺬﻟﻚ ﻳﻔﻀﻞ ﰱ ﻫـﺬﻩ ﺍﳊﺎﻟـﺔ‬ ‫ﺍﳌﻌﺪﻥ ﺍﻟﺬﻯ ﻟﻪ ﺃﻛﱪ ﻣﻘﺎﻭﻣﺔ ﺷﺪ ﻟﻮﺣﺪ ﺍﻟﻮﺯﻥ ﻭﺗﺴﻤﻰ ﻫﺬﻩ ﺍﳋﺎﺻﻴﺔ ﻭﻫﻰ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻟﻮﺣﺪﺓ ﺍﻟﻮﺯﻥ‬ ‫ﺑﺎﳌﻘﺎﻭﻣﺔ ﺍﻟﻨﻮﻋﻴﺔ ﻟﻠﺸﺪ‪.‬‬

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‫ ‬ ‫ ‬ ‫ ! ‬ ‫‪ 1-3‬‬

‫ﺇﻥ ﺇﲡﺎﻩ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻻﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﻣﺎ ﻫﻮ ﺇﻻ ﺣﺎﻟﺔ ﻋﻜﺴﻴﺔ ﻻﲡـﺎﻩ ﺍﳊﻤـﻞ ﰱ ﺍﺧﺘﺒـﺎﺭ ﺍﻟـﺸﺪ‪.‬‬ ‫ﻭﻳﺴﺘﺨﺪﻡ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﻋﺎﺩﺓ ﻛﺄﺳﺎﺱ ﻟﻘﺒﻮﻝ ﺍﳌﻮﺍﺩ ﻏـﲑ ﺍﳌﻌﺪﻧﻴـﺔ ﻣﺜـﻞ ﺍﳋﺮﺳـﺎﻧﺔ ﻭﺍﳊﺠـﺎﺭﺓ‬ ‫ﻭﺍﻷﺧﺸﺎﺏ‪ .‬ﻭﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﻧﺎﺩﺭﹰﺍ ﻣﺎ ﺗﻨﺺ ﻋﻠﻴﻪ ﺍﳌﻮﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻟﻘﺒﻮﻝ ‪ ò@ ;îã†È½a@…aì½a‬ﻧﻈـﺮﹰﺍ ﻷﻥ‬ ‫ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻟﻠﻤﻌﺎﺩﻥ ﻳﻌﻄﻰ ﺍﳋﻮﺍﺹ ﺍﻟﻼﺯﻣﺔ ﻭﺍﳍﺎﻣﺔ ﻋﻦ ﺗﻠﻚ ﺍﳌﻮﺍﺩ ‪ ،‬ﻭﺇﺫﺍ ﺍﺳﺘﺨﺪﻡ ﺍﺧﺘﺒﺎﺭ ﺍﻟـﻀﻐﻂ‬ ‫ﻟﻠﺤﻜﻢ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﻓﺈﻧﻪ ﻳﻌﲔ ﻣﻨﻪ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻟﻠﻀﻐﻂ ﻓﻘﻂ‪ .‬ﺍﻟﻐﺮﺽ ﺍﻷﺳﺎﺳـﻰ ﻣـﻦ ﺇﺟـﺮﺍﺀ‬ ‫ﺍﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﻀﻐﻂ ﻟﻠﻤﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ﻭﻏﲑ ﺍﳌﻌﺪﻧﻴﺔ ﻫﻮ ﺑﻴﺎﻥ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﳍﺬﻩ ﺍﳌﻮﺍﺩ ﰱ ﺍﻟـﻀﻐﻂ‬ ‫ﻓﻤﺜﻼ ﰱ ﺍﳌﻮﺍﺩ ﺍﳌﻄﻴﻠﺔ ﺗﺘﻤﻜﻦ ﻣﻦ ﺗﻌﻴﲔ ﺑﻌﺾ ﺍﳋﻮﺍﺹ ﻣﺜﻞ ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﻭﺍﻟﺮﺟﻮﻋﻴﺔ ﺍﳌﺮﻧﺔ ﻭﻛﺬﻟﻚ‬ ‫ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ‪ ،‬ﻭﺃﻣﺎ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﻤﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﻓﻴﺘﻢ ﺗﻌﻴﲔ ﻣﻘﺎﻭﻣﺔ ﺍﻟـﻀﻐﻂ ﺍﻟﻘـﺼﻮﻯ‪ .‬ﺗﻮﺟـﺪ ﺑﻌـﺾ‬ ‫ﺍﻟﺼﻌﻮﺑﺎﺕ ﻭﺍﻟﻌﻮﺍﻣﻞ ﺍﻟﱴ ﲡﻌﻞ ﻧﺘﺎﺋﺞ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﻏﲑ ﺩﻗﻴﻘﺔ ﻭﺗﺆﺛﺮ ﻋﻠﻰ ﺍﺳﺘﺨﺪﺍﻡ ﺍﺧﺘﺒﺎﺭ ﺍﻟـﻀﻐﻂ‬ ‫ﻛﺎﺧﺘﺒﺎﺭ ﻗﺒﻮﻝ ﻟﻠﻤﻮﺍﺩ ﻭﻣﻦ ﻫﺬﻩ ﺍﻟﻌﻮﺍﻣﻞ ﻭﺍﻟﺼﻌﻮﺑﺎﺕ ﻣﺎ ﻳﻠﻲ‪:‬‬ ‫‪ -١‬ﺍﻟﺘﺄﺛﲑ ﲝﻤﻞ ﺍﻟﻀﻐﻂ ﳚﺐ ﺃﻥ ﻳﻜﻮﻥ ﳏﻮﺭﻳﺎ ﻭﻟﻜﻦ ﻳﺼﻌﺐ ﲢﻘﻴﻖ ﺍﻟﺘﺄﺛﲑ ﺍﶈﻮﺭﻯ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﺃﺛﻨـﺎﺀ‬ ‫ﺍﻻﺧﺘﺒﺎﺭ‪.‬‬ ‫‪ -٢‬ﻋﺪﻡ ﺍﻻﺗﺰﺍﻥ ﺍﳌﺆﻛﺪ ﻟﻠﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﰱ ﺍﻟﺘﺤﻤﻴﻞ ﺑﺎﻟﻀﻐﻂ ﺇﺫﺍ ﻣﺎ ﻗﻮﺭﻥ ﺑﺎﻟﺘﺤﻤﻴﻞ ﰱ ﺍﻟﺸﺪ‪.‬‬ ‫‪ -٣‬ﺗﻮﺍﺟﺪ ﺍﻻﺣﺘﻜﺎﻙ ﺑﲔ ﺳﻄﺤﻰ ﺭﺃﺱ ﻣﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺑﲔ ﺳﻄﺤﻰ ‪‬ﺎﻳﱴ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘـﱪﺓ ﻭﻫـﺬﺍ‬ ‫ﺍﻻﺣﺘﻜﺎﻙ ﻳﻐﲑ ﻧﺘﺎﺋﺞ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻦ ﻧﻈﲑﺍ‪‬ﺎ ﻣﻦ ﺍﻟﻌﻴﻨﺎﺕ ﺍﳌﺨﺘﱪﺓ ﰱ ﺍﻟﻀﻐﻂ ﺑﺪﻭﻥ ﺍﺣﺘﻜﺎﻙ‪.‬‬ ‫‪ -٤‬ﺍﻟﻜﱪ ﺍﻟﻨﺴﱯ ﳌﺴﺎﺣﺔ ﻣﻘﻄﻊ ﺍﻟﻌﻴﻨﺎﺕ ﺍﳌﺨﺘﱪﺓ ﰱ ﺍﻟﻀﻐﻂ ﻟﻴﺤﺪﺙ ﺇﺗﺰﺍﻥ ﻟﻠﻌﻴﻨﺔ ﺃﺛﻨـﺎﺀ ﺍﻟﺘﺤﻤﻴـﻞ‪،‬‬ ‫ﻭﻳﺘﺴﺒﺐ ﺫﻟﻚ ﰱ ﺿﺮﻭﺭﺓ ﺗﻮﺍﺟﺪ ﻣﺎﻛﻴﻨﺎﺕ ﺫﺍﺕ ﺳﻌﺎﺕ ﻋﺎﻟﻴﺔ ﺃﻭ ﺍﺳﺘﺨﺪﺍﻡ ﻋﻴﻨﺎﺕ ﺻﻐﲑﺓ ﺗـﺆﺛﺮ‬ ‫ﻋﻠﻰ ﻧﺘﺎﺋﺞ ﺍﻻﺧﺘﺒﺎﺭ‪.‬‬ ‫‪ -٥‬ﺍﻟﻌﻴﻨﺎﺕ ﺍﻟﻨﺤﻴﻔﺔ ﺍﻟﱴ ﻳﻜﻮﻥ ﺍﺭﺗﻔﺎﻋﻬﺎ ﻛﺒﲑ ﺗﺴﺒﺐ ﺣﺪﻭﺙ ﺍﻧﺒﻌﺎﺝ ﺃﺛﻨﺎﺀ ﺍﻻﺧﺘﺒﺎﺭ ﳑﺎ ﻳﻨـﺘﺞ ﻋﻨـﻬﺎ‬ ‫ﻋﺪﻡ ﺩﻗﺔ ﻧﺘﺎﺋﺞ ﺍﻻﺧﺘﺒﺎﺭ‪.‬‬

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‫‪ &'( $% # 2-3‬‬

‫ﻋﻨﺪﻣﺎ ﺗﺘﻌﺮﺽ ﻋﻴﻨﺔ ﺇﺳﻄﻮﻧﻴﺔ ﺍﻟﺸﻜﻞ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ﺇﱃ ﲪﻞ ﺿﻐﻂ ﻓﺈ‪‬ﺎ ﺗﻨﻀﻐﻂ ﻭﻳﺘﺴﺒﺐ ﺫﻟﻚ ﺃﻥ‬ ‫ﺗﺄﺧﺬ ﺍﻟﻌﻴﻨﺔ ﺍﻟﺸﻜﻞ ﺍﻟﱪﻣﻴﻠﻰ )‪ (Barrel‬ﻧﺘﻴﺠﺔ ﻟﻠﺰﻳﺎﺩﺓ ﰱ ﺍﻟﻌﺮﺽ ﺍﳌﺼﺎﺣﺒﺔ ﻟﻠﻨﻘﺺ ﰱ ﺍﻻﺭﺗﻔـﺎﻉ‪،‬‬ ‫ﻭﺗﻮﺍﺟﺪ ﻗﻮﻯ ﺍﻻﺣﺘﻜﺎﻙ ﺑﲔ ﺍﻟﻌﻴﻨﺔ )ﻋﻨﺪ ﺗﻘﺎﻃﻊ ‪‬ﺎﻳﺘﻴﻬﺎ ﺍﶈﻤﻠﺘﲔ( ﻭﺭﺃﺱ ﻣﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻳﺴﺒﺐ ﻗﻠـﺔ‬ ‫ﺍﻟﺰﻳﺎﺩﺓ ﰱ ﺍﻟﻌﺮﺽ ﻋﻨﺪ ﻣﻘﺎﻃﻊ ‪‬ﺎﻳﱴ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻋﻨﻬﺎ ﰱ ﻣﻘﻄﻊ ﻣﻨﺘﺼﻒ ﺍﻟﻌﻴﻨﺔ ﺑﺸﻜﻞ ﺗﺪﺭﳚﲕ ﺗﺒﻌﺎ‬ ‫ﳌﺪﻯ ﺗﺄﺛﲑ ﻗﻮﻯ ﺍﻻﺣﺘﻜﺎﻙ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪.(١-٣‬‬ ‫=‬

‫ﺍﻟﻌﻴﻨﺔ ﺍﻻﺳﻄﻮﺍﻧﻴﺔ‬ ‫ﻗﺒﻞ ﺍﻟﺘﺤﻤﻴﻞ‬

‫ﺱ ـ‬

‫ـﺱ‬

‫ﺹ ــ‬

‫ــ ﺹ‬

‫ﺍﻟﻌﻴﻨﺔ ﺑﻌﺪ ﺍﻟﺘﺤﻤﻴﻞ ﰱ ﺍﻟﻀﻐﻂ‬ ‫ﺗﺄﺧﺬ ﺍﻟﺸﻜﻞ ﺍﻟﱪﻣﻴﻠﻲ‬

‫ﻣﻘﻄﻊ ﺍﻟﻌﻴﻨﺔ ﺱ‪ -‬ﺱ‬ ‫@@‬ ‫ﺑﻌﺪ ﺍﻟﺘﺤﻤﻴﻞ‬

‫ﻣﻘﻄﻊ ﺍﻟﻌﻴﻨﺔ ﺹ‪ -‬ﺹ‬ ‫ﺑﻌﺪ ﺍﻟﺘﺤﻤﻴﻞ ﰱ ﺍﻟﻀﻐﻂ‬

‫‘‪@ @ÁÌšÛa@‰bjna@óÏ@òÜîĐ½a@æ…bÈàÜÛ@ïÜîßÛa@ÝØ’Ûa@të†y@HQMSI@ÝØ‬‬ ‫‪Ductile Materials@òÜîĐ½a@òîã†È½a@…aì½a@ÚìÜ@QMRMS‬‬

‫ﺇﺫﺍ ﺍﺧﺘﱪﺕ ﻋﻴﻨﺔ ﻣﻦ ﻣﻌﺪﻥ ﻣﻄﻴﻞ ﻣﺜﻞ ﺍﻟﺼﻠﺐ ﺍﻟﻄﺮﻯ ﰱ ﺍﻟﻀﻐﻂ ﺣﱴ ﺣﺪ ﺍﳌﺮﻭﻧـﺔ ﻓﺈﻧﻨـﺎ ﻧﻼﺣـﻆ‬ ‫ﺗﻮﺍﺟﺪ ﺟﺰﺀ ﻣﺴﺘﻘﻴﻢ ﲟﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻟﺘﺸﻜﻴﻞ ﺣﱴ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻛﺬﻟﻚ ﻳﻮﺟﺪ ﻣﻨﻄﻘـﺔ ﻟﻠﺨـﻀﻮﻉ‪،‬‬ ‫ﻭﺍﺳﺘﻤﺮﺍﺭ ﺍﻟﺘﺤﻤﻴﻞ ﻓﻮﻕ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﻓﺈﻥ ﺍﻟﻌﻴﻨﺔ ﻳﺰﻳﺪ ﺍﻧﻀﻐﺎﻃﻬﺎ ﰒ ﺗﺘﻔﻠﻄﺢ ﺑﺪﻭﻥ ﺣﺪﻭﺙ ﻛﺴﺮ ﻟﻠﻌﻴﻨﺔ‬ ‫ﻣﻬﻤﺎ ﺯﺍﺩ ﺍﻟﺘﺤﻤﻴﻞ ﻛﻤﺎ ﻳﺘﻀﺢ ﰱ ﺷﻜﻞ )‪.(٢-٣‬‬ ‫‪Semi-Ductile@òÜîĐ½a@Ñ–ã@òîã†È½a@…aì½a@ÚìÜ@RMRMS‬‬

‫ﺇﺫﺍ ﻛﺎﻧﺖ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻣﻦ ﻣﻌﺪﻥ ﻧﺼﻒ ﻣﻄﻴﻞ ﻣﺜﻞ ﺍﻟﻨﺤﺎﺱ ﺍﻷﺻﻔﺮ ﻓﺈﻥ ﺍﻟﻌﻴﻨﺔ ﺗﻨﻀﻐﻂ ﻣﻊ ﺯﻳـﺎﺩﺓ‬ ‫ﺍﻟﺘﺤﻤﻴﻞ ﰒ ﺗﻨﻜﺴﺮ ﻋﻠﻰ ﻣﺴﺘﻮﻯ ﻳﻌﻤﻞ ﺯﺍﻭﻳﺔ ﺣﻮﺍﱃ ‪ ٥٠‬ﺩﺭﺟﺔ ﻣﻊ ﺍﻻﲡﺎﻩ ﺍﻷﻓﻘﻰ‪ .‬ﻭﳝﻜﻦ ﻣﻼﺣﻈـﺔ‬ ‫ﻭﺟﻮﺩ ﺟﺰﺀ ﻣﺴﺘﻘﻴﻢ ﲟﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻻﻧﻀﻐﺎﻁ ﺣﱴ ‪‬ﺎﻳﺔ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻭﻗﺪ ﻳﻼﺣﻆ ﺃﻳﻀﹰﺎ ﺇﻣﺎ ﺗﻮﺍﺟـﺪ‬ ‫ﺃﻭ ﻋﺪﻡ ﺗﻮﺍﺟﺪ ﻣﻨﻄﻘﺔ ﻟﻠﺨﻀﻮﻉ ﺗﺒﻌﺎ ﻟﻈﺮﻭﻑ ﻣﻌﺪﻥ ﺍﻟﻌﻴﻨﺔ ﻣﻦ ﺍﻟﻮﺟﻬﺔ ﺍﻟﺘﺸﻐﻴﻠﻴﺔ ﺃﻭ ﺍﳌﻌﺎﻣﻠﺔ ﺍﳊﺮﺍﺭﻳﺔ‪،‬‬ ‫ﰒ ﺑﻌﺪ ﺫﻟﻚ ﻳﺄﺧﺬ ﺍﳌﻨﺤﲎ ﺷﻜﻼ ﺣﱴ ﺍﻟﻮﺻﻮﻝ ﻟﻠﺤﻤﻞ ﺍﻷﻗﺼﻰ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪.(٢-٣‬‬ ‫‪Brittle Materials@òÐ–ÔÛa@òîã†È½a@…aì½a@ÚìÜ@SMRMS‬‬

‫ﻋﻨﺪﻣﺎ ﲣﺘﱪ ﻋﻴﻨﺔ ﻣﻦ ﻣﻌﺪﻥ ﻗﺼﻒ ﻣﺜﻞ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ ﻓﻴﺤﺪﺙ ‪‬ﺎ ﺍﻧﻀﻐﺎﻁ ﻗﻠﻴﻞ ﺟﺪﹰﺍ ﰒ ﺗﻨﻜﺴﺮ ﻋﻠـﻰ‬ ‫ﻣﺴﺘﻮﻯ ﳝﻴﻞ ﻋﻠﻰ ﺍﻷﻓﻘﻰ ﺑﺰﺍﻭﻳﺔ ‪ ٦٠-٥٥‬ﺩﺭﺟﺔ ﻭﻳﻜﻮﻥ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻟﺘﺸﻜﻞ ﻛﻤﺎ ﻳﺘـﺒﲔ ﻣـﻦ‬ ‫ﺍﻟﺸﻜﻞ )‪ (٢-٣‬ﻭﻳﻼﺣﻆ ﻋﺪﻡ ﺗﻮﺍﺟﺪ ﻣﻨﻄﻘﺔ ﺧﻀﻮﻉ ﻭﺗﻮﺍﺟﺪ ﻣﻘﺎﻭﻣﺔ ﻗﺼﻮﻯ ﻟﻠﻀﻐﻂ‪.‬‬

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Load ‫ﺍﳊﻤﻞ‬

L‫ د‬J L‫د‬K‫ م‬J‫ دم‬L‫د‬K ‫ אصא אدوאא‬

‫ﻣﺎﺩﺓ ﻣﻄﻴﻠﺔ‬ Ductile Material ‫ﻣﺜﻞ ﺍﻟﺼﻠﺐ ﺍﻟﻄﺮﻱ‬

‫ﺍﻟﺘﺸﻜﻞ‬


Deformation

‫ﻣﺎﺩﺓ ﻧﺼﻒ ﻣﻄﻴﻠﺔ‬ Semi-Ductile Material

‫ﻣﺜﻞ ﺍﻟﻨﺤﺎﺱ‬

Deformation


φ = 50ο


‫ﻣﺎﺩﺓ ﻗﺼﻔﺔ‬ Brittle Material

‫ﻣﺜﻞ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ‬

@@

Deformation

φ = 55−60 55−60ο


@@ @@

@ @NÁÌšÛa@‰bjna@óÏ@òÜîĐ½a@Ñ–ãë@òÐ–ÔÛaë@òÜîĐ½a@æ…bÈ½a@ÚìÜ@HRMSI@ÝØ‘

٦٣


‫‪@ @@ÁÌšÛa@óÏ@ÞbÈÐãüaë@…bèu⁄a@óäzäß@TMRMS‬‬ ‫ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻌﺎﺩﻱ ﰱ ﺍﻟﻀﻐﻂ ﳝﻜﻦ ﺭﲰﻪ ﻭﺗﻮﻗﻴﻌﻪ ﺑﺎﺳﺘﺨﺪﺍﻡ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻟﺘﺸﻜﻴﻞ‬ ‫ﻭﺍﻋﺘﺒﺎﺭ ﺃﻥ‪:‬‬ ‫• ﺍﻹﺟﻬﺎﺩ ﺍﻟﻌﺎﺩﻱ ﰱ ﺍﻟﻀﻐﻂ =‬ ‫• ﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻌﺎﺩﻱ ﰱ ﺍﻟﻀﻐﻂ =‬

‫ﺍﳊﻤﻞ ﻋﻨﺪ ﺃﻯ ﻧﻘﻄﺔ )‪(p‬‬

‫‪P‬‬ ‫‪Ao‬‬

‫ﺍﳌﺴﺎﺣﺔ ﺍﻷﺻﻠﻴﺔ )‪(Ao‬‬ ‫ﺍﻻﻧﻀﻐﺎﻁ ﺍﳊﺎﺩﺙ ﻋﻦ ﺃﻯ ﻧﻘﻄﺔ )‪(∆L‬‬

‫‪∆L‬‬ ‫‪Lo‬‬

‫ﺍﻟﻄﻮﻝ ﺍﻷﺻﻠﻰ )‪(Lo‬‬

‫= ‪σC‬‬

‫= ‪εC‬‬

‫ﻭﻳﺒﲔ ﺍﻟﺸﻜﻞ )‪ (٣-٣‬ﺍﳌﻨﺤﻨﻴﺎﺕ ﺍﻟﺒﻴﺎﻧﻴﺔ ﻟﻺﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻌﺎﺩﻯ ﻟﺒﻌﺾ ﺍﳌﻌﺎﺩﻥ ﺍﳌﺨﺘﻠﻔﺔ ﲢﺖ ﺗﺄﺛﲑ‬ ‫ﺃﲪﺎﻝ ﺍﻟﻀﻐﻂ‪.‬‬

‫‪Mild Steel‬‬

‫ﺣﺪﻳﺪ ﺯﻫﺮ‬

‫ﳓﺎﺱ‬

‫‪Cast Iron‬‬ ‫‪60‬‬

‫ِ‪Copper‬‬

‫‪40‬‬

‫ﺃﻟﻮﻣﻨﻴﻮﻡ ‪Aluminum‬‬

‫ﺍﻻﺟﻬﺎﺩ ﺍﻟﻌﺎﺩﻱ ﻛﺞ‪/‬ﻣﻢ‪٢‬‬

‫ﺻﻠﺐ ﻃﺮﻱ‬

‫‪80‬‬

‫‪20‬‬

‫‪0.5‬‬

‫‪0.4‬‬

‫‪0.3‬‬

‫‪0.2‬‬

‫‪0.1‬‬

‫ﺍﻻﻧﻔﻌﺎﻝ ﺍﻟﻌﺎﺩﻱ ﻣﻢ‪/‬ﻣﻢ‬

‫‪0‬‬

‫‪0‬‬

‫‘‪@ @NÁÌšÛa@óÏ@òÐÜn‚½a@æ…bÈàÜÛ@ô…bÈÛa@ÞbÈÐãüaë@…bèu⁄a@pbîäzäß@HSMSI@ÝØ‬‬

‫ﻛﻤﺎ ﺃﻧﻪ ﳝﻜﻦ ﺃﻳﻀﺎ ﺗﻮﻗﻴﻊ ﻭﺭﺳﻢ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺍﳊﻘﻴﻘﻲ ﰱ ﺍﻟﻀﻐﻂ ﺑﺎﻋﺘﺒﺎﺭ ﺃﻥ‪:‬‬ ‫• ﺍﻹﺟﻬﺎﺩ ﺍﳊﻘﻴﻘﻲ ﰱ ﺍﻟﻀﻐﻂ =‬

‫ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻋﻨﺪ ﺃﻯ ﻧﻘﻄﺔ ) ‪( Pi‬‬ ‫ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻋﻨﺪ ﻫﺬﻩ ﺍﻟﻠﺤﻈﺔ )‪(Ai‬‬ ‫‪Pi‬‬ ‫‪Ai‬‬

‫‪٦٤‬‬

‫= ‪σc‬‬


‫• ﺍﻻﻧﻔﻌﺎﻝ ﺍﳊﻘﻴﻘﻲ ﰱ ﺍﻟﻀﻐﻂ = ﻟﻮﻏﺎﺭﺗﻴﻢ ﺍﻷﺳﺎﺱ )‪(e‬‬

‫ﺍﳌﺴﺎﺣﺔ ﺍﻷﺻﻠﻴﺔ‬ ‫ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻋﻨﺪ ﺃﻯ ﳊﻈﺔ‬

‫‪εc = Loge Ao‬‬ ‫‪Ai‬‬

‫ﻭﺍﻟﺸﻜﻞ )‪ (٤-٣‬ﻳﺒﲔ ﻣﻨﺤﻨﻴﺎﺕ ﻣﺘﻌﺪﺩﺓ ﳌﻌﺎﺩﻥ ﳐﺘﻠﻔﺔ ﻟﻺﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺍﳊﻘﻴﻘﻰ‪.‬‬

‫ﳓﺎﺱ‬

‫‪Mild Steel‬‬

‫ِ‪Copper‬‬ ‫‪60‬‬

‫ﺃﻟﻮﻣﻨﻴﻮﻡ‬

‫ﻛﺞ‪/‬ﻣﻢ‪٢‬‬

‫‪Aluminum‬‬

‫‪40‬‬

‫ﺍﻻﺟﻬﺎﺩ ﺍﳊﻘﻴﻘﻲ‬

‫ﺻﻠﺐ ﻃﺮﻱ‬

‫‪80‬‬

‫‪20‬‬

‫‪0.5‬‬

‫‪0.4‬‬

‫‪0.3‬‬

‫ﺍﻻﻧﻔﻌﺎﻝ ﺍﳊﻘﻴﻘﻲ ﻣﻢ‪/‬ﻣﻢ‬

‫‪0.2‬‬

‫‪0.1‬‬

‫‪0‬‬

‫‪0‬‬

‫‘‪@ @NÁÌšÛa@óÏ@æ…bÈàÜÛ@óÔîÔ§a@ÞbÈÐãüaë@…bèu⁄a@óäzäß@HTMSI@ÝØ‬‬

‫‪@ @ÁÌšÛa@óÏ@òîØîãbØî½a@ãìä@UMRMS‬‬

‫‪ -1‬‬ ‫ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﳌﻮﺍﺩ ﺍﳌﻄﻴﻠﺔ ﰱ ﺍﻟﻀﻐﻂ‪ ،‬ﻭﺟﺪ ﺃﻥ ﺍﻻﻧﻔﻌﺎﻝ ﺍﳊﺎﺩﺙ ﻳﺘﻨﺎﺳﺐ ﻣﻊ ﺍﻹﺟﻬﺎﺩ ﻛﻤـﺎ ﰱ ﺍﺧﺘﺒـﺎﺭ‬ ‫ﺍﻟﺸﺪ‪ ،‬ﻭﻳﻼﺣﻆ ﺃﻳﻀﺎ ﺃﻥ ﻗﻴﻤﱵ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻭﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﰱ ﺍﻟﻀﻐﻂ ﻭﺍﻟﺸﺪ ﻣﺘﻄﺎﺑﻘﲔ ﰱ ﺍﳌﻌﺎﺩﻥ‬ ‫ﺍﳌﻄﻴﻠﺔ ﻭﺑﺎﻷﺧﺺ ﺍﻟﺼﻠﺐ ﺍﻟﻄﺮﻱ‪ .‬ﻭﻛﻠﻤﺎ ﺯﺍﺩ ﺍﳊﻤﻞ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﻳﻼﺣﻆ ﺯﻳﺎﺩﺓ ﻣـﺴﺎﺣﺔ ﺍﳌﻘﻄـﻊ ﻭﻻ‬ ‫ﳛﺪﺙ ﺍ‪‬ﻴﺎﺭ ﻟﻠﻤﻮﺍﺩ ﺍﳌﻄﻴﻠﺔ‪ .‬ﻛﻤﺎ ﺃﻧﻪ ﳝﻜﻦ ﲢﺪﻳﺪ ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﺣﻴﺚ ﺃﻧﻪ ﻳـﺴﺎﻭﻯ‬ ‫ﻣﻴﻞ ﺍﳋﻂ ﺍﳌﺴﺘﻘﻴﻢ ﻣﻦ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﳌﻨﻄﻘﺔ ﺍﳌﺮﻭﻧﺔ ﻛﻤﺎ ﻫﻮ ﺍﳊﺎﻝ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻭﺫﻟﻚ‬ ‫ﻟﻠﻤﻮﺍﺩ ﺍﳌﻄﻴﻠﺔ‪ .‬ﻭﳝﻜﻦ ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﺑﻌﺾ ﺍﳋﻮﺍﺹ ﺍﳍﺎﻣﺔ ﻟﻠﻤﻮﺍﺩ ﺍﳌﻄﻴﻠﺔ ﻣﻦ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﻣﺜﻞ ﺣﺪ‬ ‫ﺍﻟﺘﻨﺎﺳﺐ ﻭﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ‪ ،‬ﻭﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﺑﺎﺳﺘﺨﺪﺍﻡ ﻣﻨﺤﲎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ‪ .‬ﻭﻳﻔﻀﻞ ﺃﻥ ﺗﻜـﻮﻥ‬ ‫ﺍﻟﻌﻴﻨﺎﺕ ﺍﳌﺨﺘﱪﺓ ﻋﻴﻨﺎﺕ ﺍﺳﻄﻮﺍﻧﻴﺔ ﺍﻟﺸﻜﻞ ﻭﺍﻟﻨﺴﺒﺔ ﺍﶈﺪﺩﺓ ﺑﲔ ﺍﻟﻘﻄﺮ ﻭﺍﻻﺭﺗﻔﺎﻉ ﻃﺒﻘﺎ ﻟﻠﻤﻮﺻﻔﺎﺕ‪.‬‬

‫‪٦٥‬‬


‫‪ -2‬‬ ‫ﻧﻈﺮﹰﺍ ﻷﻥ ﳑﻄﻮﻟﻴﺔ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ ﰱ ﺍﺧﺘﺒﺎﺭ ‪ †@ ’;Ûa‬ﺻﻐﲑﺓ ﺟﺪﹰﺍ ﻟﺬﻟﻚ ﻓﺈﻥ ﻣﻘﺎﻭﻣﺘﻪ ﻟﻠﻀﻐﻂ ﺫﺍﺕ ﺃﳘﻴـﺔ‬ ‫ﻛﱪﻯ ﰱ ﺍﻟﺘﺼﻤﻴﻢ ‪ .‬ﳝﻜﻦ ﺍﺳﺘﺨﺪﺍﻡ ﻣﻘﺎﻳﻴﺲ ﺍﻟﺘﺸﻜﻞ ﺑﺪﻗﺔ ﻋﺎﻟﻴﺔ ﻟﻘﻴﺎﺱ ﺍﻻﻧﻀﻐﻂ ﻟﻠﻤـﻮﺍﺩ ﺍﻟﻘـﺼﻔﺔ‬ ‫ﻭﺫﻟﻚ ﻟﻠﻘﻴﻢ ﺍﻟﺼﻐﲑﺓ ﻣﻦ ﺍﻷﲪﺎﻝ ﻟﻠﺘﺄﻛﺪ ﻣﻦ ﺩﻗﺔ ﺍﻟﻌﻼﻗﺔ ﺑﲔ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻟﻠﻘﻴﻢ ﺍﻟﺼﻐﲑﺓ ﻧﺴﺒﻴﺎﹰ‪،‬‬ ‫ﻭﻳﻼﺣﻆ ﺃﻧﻪ ﻻ ﻳﻮﺟﺪ ﺃﻯ ﺗﻨﺎﺳﺐ ﺑﲔ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻟﻠﻤﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﰱ ﺍﻟﻀﻐﻂ‪ .‬ﻭﺗﻌﱪ ﺍﻟﻌﻼﻗـﺔ‬ ‫ﺍﻵﺗﻴﺔ ﺑﲔ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻋﻦ ﻗﻴﻤﺔ ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﻟﻠﻤﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ‪:‬‬ ‫‪σn‬‬ ‫‪ε‬‬

‫=‪E‬‬

‫• ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ = ‪E‬‬

‫• ﺍﻻﺟﻬﺎﺩ = ‪σ‬‬ ‫• ﺍﻻﻧﻔﻌﺎﻝ = ‪ε‬‬ ‫• ﺛﺎﺑﺖ = ‪n‬‬

‫ﻭﺗﺼﻠﺢ ﻫﺬﻩ ﺍﻟﻌﻼﻗﺔ ﻟﻠﻤﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﺍﳌﻌﺪﻧﻴﺔ ﻣﺜﻞ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ ﻭﻏـﲑ ﺍﳌﻌﺪﻧﻴـﺔ ﻣﺜـﻞ ﺍﳋﺮﺳـﺎﻧﺔ‬ ‫ﻭﺍﻷﺣﺠﺎﺭ‪ ،‬ﻭﳛﺪﺙ ﺍﻻ‪‬ﻴﺎﺭ ﻟﻠﻤﻌﺎﺩﻥ ﺍﻟﻘﺼﻔﺔ ﰱ ﺍﻟﻀﻐﻂ ﻟﻠﻜﺴﺮ ﻋﻠﻰ ﻣﺴﺘﻮﻯ ﻣﺎﺋﻞ ﺑﺰﺍﻭﻳﺔ ﻋﻠﻰ ﳏﻮﺭ‬ ‫ﺍﻻﺟﻬﺎﺩ ﺑﺴﺒﺐ ﻗﻮﻯ ﺍﻟﻘﺺ ﻋﻠﻰ ﺍﳌﺴﺘﻮﻯ ﺍﳌﺎﺋﻞ‪ ،‬ﺃﻣﺎ ﺍﳌﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﻏﲑ ﺍﳌﻌﺪﻧﻴﺔ ﻣﺜﻞ ﺍﻷﺣﺠﺎﺭ ﻭﺍﳌﻮﺍﺩ‬ ‫ﺍﻷﲰﻨﺘﻴﺔ ﻭﺍﳋﺮﺳﺎﻧﻴﺔ ﻓﺈ‪‬ﺎ ﺗﻨﻬﺎﺭ ﺑﺘﺄﺛﲑ ﻗﺺ ﻣﺰﺩﻭﺝ ﻭﻳﻜﻮﻥ ﺷﻜﻞ ﻋﻴﻨﺎﺕ ﺍﻹﺧﺘﺒﺎﺭ ﰱ ﺍﻟﻀﻐﻂ ﺇﻣﺎ ﻋﻠﻰ‬ ‫ﺷﻜﻞ ﻣﻜﻌﺒﺎﺕ ﺃﻭ ﺇﺳﻄﻮﺍﻧﺎﺕ ﻗﻴﺎﺳﻴﺔ ﺣﺴﺐ ﺍﳌﻮﺍﺻﻔﺎﺕ ﻭﳛﺪﺙ ﺍﻟﻜﺴﺮ ﻃﺒﻘﹰﺎ ﻟﻠﻘﺺ ﺍﳌﺰﻭﺩﺝ ﺇﻣﺎ ﻋﻠﻰ‬ ‫ﺷﻜﻞ ﻫﺮﻡ ﻟﻠﻌﻴﻨﺎﺕ ﺍﳌﻜﻌﺒﺔ ﻭﺍﳌﻨﺸﻮﺭﻳﺔ ﺃﻭ ﺷﻜﻞ ﳐﺮﻭﻁ ﻟﻠﻌﻴﻨﺎﺕ ﺍﻻﺳﻄﻮﺍﻧﻴﺔ‪ .‬ﻳﻜﻔﻰ ﻟﻠﻤﻮﺍﺩ ﺍﻟﻘـﺼﻔﺔ‬ ‫ﻣﻌﺮﻓﺔ ﺧﻮﺍﺹ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻀﻐﻂ ﻟﻠﻌﻴﻨﺎﺕ ﺍﳌﺨﺘﱪﺓ‪ .‬ﻛﺬﻟﻚ ﺍﻟﻨﺴﺒﺔ ﺑﲔ ﺍﻻﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﻟﻠﻤﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ‬ ‫ﺗﺘﻮﻗﻒ ﻋﻠﻰ ﻗﻴﻤﺔ ﺍﻹﺟﻬﺎﺩ ﺣﻴﺚ ﺗﻜﻮﻥ ﺍﻟﻨﺴﺒﺔ ﻛﺒﲑﺓ ﻟﻺﺟﻬﺎﺩﺍﺕ ﺍﻟﺼﻐﲑﺓ‪ ،‬ﻭﻻﺯﻡ ﻣﻦ ﺑﻴﺎﻥ ﺍﻻﺟﻬـﺎﺩ‬ ‫ﺍﶈﺴﻮﺏ ﻋﻠﻰ ﺃﺳﺎﺳﻪ ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﻋﻨﺪ ﺍﺳﺘﺨﺪﺍﻣﻪ ﰱ ﺣﺴﺎﺏ ﺍﻟﺘﺼﻤﻴﻢ ﻭﻳﻜﻮﻥ ﻫـﺬﺍ ﺿـﺮﻭﺭﻳﹸﺎ ﰱ‬ ‫ﺗﻄﺒﻴﻘﺎﺕ ﺍﳋﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ‪٠‬‬

‫‪٦٦‬‬


‫‪ #) * 3-3‬‬

‫‪@ @ÁÌšÛa@óÏ@ñn‚½a@pbäîÈÛa@QMSMS‬‬ ‫ﻋﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﺫﺍﺕ ﺍﻟﺸﻜﻞ ﺍﻻﺳﻄﻮﺍﱏ ﻳﻔﻀﻞ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﻋﻦ ﺍﻷﺷﻜﺎﻝ ﺍﻵﺧﺮﻯ‬ ‫ﻷ‪‬ﺎ ﺗﻌﻄﻰ ﺇﺟﻬﺎﺩﺍﺕ ﻣﻨﺘﻈﻤﺔ ﺑﺎﻟﻨﺴﺒﺔ ﶈﻴﻂ ﺍﻟﺴﻄﺢ ﺍﻟﺪﺍﺋﺮﻱ ﻟﻘﺎﻋﺪﰐ ﺍﻟﻌﻴﻨﺔ ﺍﻻﺳﻄﻮﺍﻧﻴﺔ ﻭﻛـﺜﲑﹰﺍ ﻣـﺎ‬ ‫ﻳﺘﺤﺘﻢ ﻋﻠﻴﻨﺎ ﺍﺳﺘﺨﺪﺍﻡ ﻋﻴﻨﺎﺕ ﻣﻜﻌﺒﺔ ﺃﻭ ﻣﻨﺸﻮﺭﻳﺔ ﺍﻟﺸﻜﻞ ﻻﺧﺘﺒﺎﺭﻫﺎ ﰱ ﺍﻟﻀﻐﻂ ﻣﺜﻞ ﻗﻮﺍﻟﺐ ﺍﻟﻄﻮﺏ ﺃﻭ‬ ‫ﺃﻧﻮﺍﻉ ﺍﻟﺒﻼﻁ ﺍﳌﺨﺘﻠﻔﺔ‪ .‬ﺇﻥ ﻟﻠﻨﺴﺒﺔ ﺑﲔ ﺍﻟﻄﻮﻝ ﻭﺍﻟﻘﻄﺮ ﻟﻠﻌﻴﻨﺎﺕ ﺍﻻﺳﻄﻮﺍﻧﻴﺔ ﰱ ﺍﻟﻀﻐﻂ ﺃﳘﻴـﺔ ﻛـﱪﻯ‬ ‫ﺣﻴﺚ ﺃﻥ ﻫﺬﻩ ﺍﻟﻨﺴﺒﺔ ﺗﺘﺄﺛﺮ ﺑﺒﻌﺾ ﺍﻟﻌﻮﺍﻣﻞ ﻓﻘﺪ ﻭﺟﺪ ﺃﻧﻪ ﻛﻠﻤﺎ ﺯﺍﺩ ﻃﻮﻝ ﺍﻟﻌﻴﻨﺔ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻘﻄﺮﻫﺎ ﻛﻠﻤـﺎ‬ ‫ﻛﺎﻥ ﻫﻨﺎﻙ ﺇﺣﺘﻤﺎﻝ ﻟﻮﺟﻮﺩ ﺇﳓﻨﺎﺀ ﺯﻳﺎﺩﺓ ﻋﻦ ﻋﺪﻡ ﺍﻧﺘﻈﺎﻡ ﺗﻮﺯﻳﻊ ﺍﻹﺟﻬﺎﺩﺍﺕ ﻋﻠﻰ ﺍﻷﺳﻄﺢ ﺍﻟﻌﻤﻮﺩﻳـﺔ‪،‬‬ ‫ﻭﻗﺪ ﹶﺃﻗﺘﺮﺡ ﺃﻻ ﺗﺰﻳﺪ ﻧﺴﺒﺔ ﺍﻟﻄﻮﻝ ﺇﱃ ﺍﻟﻘﻄﺮ ﻋﻦ )‪ (١٠‬ﻭﻛﻠﻤﺎ ﻛﺎﻧﺖ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺴﺘﺨﺪﻣﺔ ﻗـﺼﲑﺓ ﻓـﺈﻥ‬ ‫ﺗﺄﺛﲑ ﺍﻻﺣﺘﻜﺎﻙ ﻋﻨﺪ ﺍﻟﻨﻬﺎﻳﺔ ﻳﺼﺒﺢ ﺫﻭ ﺃﳘﻴﺔ ﻭﺧﺼﻮﺻﺎ ﻟﻸﻃﻮﺍﻝ ﺃﻗﻞ ﻣﻦ ‪ ١,٥‬ﻣﺮﺓ ﻣﻦ ﻗﻄـﺮ ﺍﻟﻌﻴﻨـﺔ‬ ‫ﺣﻴﺚ ﺍﳌﺴﺘﻮﻳﺎﺕ ﺍﻟﻘﻄﺮﻳﺔ ﺍﻟﱴ ﳛﺪﺙ ﻋﻠﻴﻬﺎ ﺍﻻ‪‬ﻴﺎﺭ ﺗﻘﻄﻊ ﺍﻟﻘﺎﻋﺪﻩ ﳑﺎ ﻳﻨﺘﺞ ﻋﻨـﻪ ﺯﻳـﺎﺩﺓ ﰱ ﺍﳌﻘﺎﻭﻣـﺔ‬ ‫ﺍﻟﻈﺎﻫﺮﻳﺔ‪ .‬ﻭﻋﻤﻮﻣﹸﺎ ﺍﻟﻨﺴﺒﺔ ﺷﺎﺋﻌﺔ ﺍﻻﺳﺘﻌﻤﺎﻝ ﺑﲔ ﺍﻟﻄﻮﻝ ﻭﺍﻟﻘﻄﺮ ﻫﻰ )‪ (٢‬ﺃﻭ ﺃﻛﺜﺮ ﻭﲣﺘﻠﻒ ﻫﺬﻩ ﺍﻟﻨﺴﺒﺔ‬ ‫ﺑﺈﺧﺘﻼﻑ ﺍﳌﻮﺍﺩ ﺍﳌﺴﺘﺨﺪﻣﺔ‪ .‬ﻭﺇﺫﺍ ﻛﺎﻥ ﺍﳌﻄﻠﻮﺏ ﻣﻦ ﺍﻻﺧﺘﺒﺎﺭ ﻣﻌﺮﻓﺔ ﻭﺗﻌﻴﲔ ﺍﻻﻧﻔﻌﺎﻝ ﰱ ﻋﻴﻨﺔ ﺍﺧﺘﺒـﺎﺭ‬ ‫ﻣﻌﻴﻨﺔ ﻓﺈﻧﻪ ﻳﻔﻀﻞ ﺍﻥ ﺗﻜﻮﻥ ﻫﺬﻩ ﺍﻟﻌﻴﻨﺔ ﻃﻮﻳﻠﺔ ﻟﻜﻰ ﻧﺘﻤﻜﻦ ﻣﻦ ﺗﺜﺒﻴﺖ ﻣﻘﺎﻳﻴﺲ ﺍﻻﻧﻔﻌـﺎﻝ‪ .‬ﻭﳚـﺐ ﺃﻥ‬ ‫ﻧﻀﻊ ﰱ ﺍﳊﺴﺒﺎﻥ ﺍﻷﺳﺲ ﺍﻟﱴ ﺗﻌﺘﻤﺪ ﻋﻠﻴﻬﺎ ﺃﺑﻌﺎﺩ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻭﻫﻰ ﻧﻮﻉ ﺍﳌﺎﺩﺓ ﻭﺍﻟﻘﻴﺎﺳﺎﺕ ﺍﳌﻄﻠﻮﺑـﺔ‬ ‫ﻭﺃﺟﻬﺰﺓ ﺍﻻﺧﺘﺒﺎﺭ ﺍﳌﺴﺘﺨﺪﻣﺔ‪ .‬ﻓﺈﻧﻪ ﳝﻜﻦ ﺍﺧﺘﻴﺎﺭ ﺍﻟﻌﻴﻨﺔ ﺍﻟﻘﺼﲑﺓ ﻟﻠﻤﻮﺍﺩ ﺍﳌﺘﺠﺎﻧﺴﺔ ﻷﻥ ﺃﻫـﻢ ﻋﻨـﺼﺮ‬ ‫ﻣﻄﻠﻮﺏ ﺗﻌﻴﻴﻨﺔ ﰱ ﻫﺬﻩ ﺍﳌﻮﺍﺩ ﻫﻰ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻟﻠﻀﻐﻂ ﻓﻘﻂ‪ .‬ﺃﻣﺎ ﺍﳌﻮﺍﺩ ﻏـﲑ ﺍﳌﺘﺠﺎﻧـﺴﺔ ﻣﺜـﻞ‬ ‫ﺍﳋﺮﺳﺎﻧﺔ ﻓﺈﻥ ﺃﺑﻌﺎﺩ ﺍﻟﻌﻴﻨﺔ ﺗﺘﻮﻗﻒ ﻋﻠﻰ ﻋﻮﺍﻣﻞ ﺃﳘﻬﺎ ﺍﳌﻘﺎﺱ ﺍﻻﻋﺘﺒﺎﺭﻯ ﺍﻷﻛﱪ ﻟﻠﺮﻛـﺎﻡ ‪ ،‬ﻓﻴﺠـﺐ ﺃﻥ‬ ‫ﺗﻜﻮﻥ ﺃﺳﻄﺢ ﺍﻟﻌﻴﻨﺔ ﺍﳌﻌﺮﺿﺔ ﻟﻠﺘﺤﻤﻴﻞ ﺃﻓﻘﻴﺔ ﻭﻣﺘﻌﺎﻣﺪﺓ ﻋﻠﻰ ﳏﻮﺭ ﺍﻟﻌﻴﻨﺔ‪ ،‬ﻭﺫﻟﻚ ﻳﻌﻤﻞ ﻏﻄﺎﺀ ﻟﻠﺴﻄﺢ‪.‬‬ ‫ﻭﳚﺐ ﺃﻥ ﺗﺴﺘﻮﰱ ﰱ ﺍﻟﻌﻴﻨﺎﺕ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﻟﻠﻤﻌﺎﺩﻥ ﺍﻻﺷﺘﺮﺍﻃﺎﺕ ﺍﻷﺗﻴﺔ‪:‬‬ ‫‪-١‬‬

‫ﳚﺐ ﺃﻥ ﺗﻜﻮﻥ ﺍﻟﻌﻴﻨﺎﺕ ﺍﳌﺨﺘﱪﺓ ﺍﺳﻄﻮﺍﻧﻴﺔ ﺍﻟﺸﻜﻞ ﻭﺫﻟﻚ ﻟﻀﻤﺎﻥ ﺗﻮﺯﻳﻊ ﺍﻟﺘﺤﻤﻴﻞ ﻣﻨﺘﻈﻤﺎ‬ ‫ﻋﻠﻰ ﻣﺴﻄﺢ ﻗﻄﺎﻉ ﻗﺎﻋﺪﺗﻰ ﺍﻟﻌﻴﻨﺔ‪.‬‬

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‫ﳚﺐ ﺃﻥ ﺗﻜﻮﻥ ﺍﻟﻌﻴﻨﺎﺕ ﺍﳌﺨﺘﱪﺓ ﺫﺍﺕ ﺇﺭﺗﻔﺎﻉ ﻻ ﻳﺘﺠﺎﻭﺯﻩ ﻋﺸﺮﺓ ﺃﻣﺜـﺎﻝ ﻗﻄـﺮ ﻣﻘﻄﻌﻬـﺎ‬ ‫ﺍﻟﺪﺍﺋﺮﻯ ﻟﻀﻤﺎﻥ ﻋﺪﻡ ﺣﺪﻭﺙ ﺍﻧﺒﻌﺎﺝ ﻟﻠﻌﻴﻨﺔ ﺍﻟﺬﻯ ﻳﺴﺒﺐ ﺗﻮﺍﺟﺪ ﻋﺰﻭﻡ ﺇﳓﻨﺎﺀ ﺇﺿﺎﻓﻴﺔ ﻣـﻊ‬ ‫ﺃﲪﺎﻝ ﺍﻟﻀﻐﻂ‪.‬‬

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‫ﳚﺐ ﺃﻥ ﻳﻜﻮﻥ ﺳﻄﺤﻲ ‪‬ﺎﻳﱵ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻣﺴﺘﻮﻳﲔ ﻭﻣﺘﻮﺍﺯﻳﲔ ﻭﻋﻤﻮﺩﻳﲔ ﻋﻠـﻰ ﳏـﻮﺭ‬ ‫ﺍﻟﻌﻴﻨﺔ ﺣﱴ ﻳﻜﻮﻥ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﳏﻮﺭﻳﹰﺎ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ‪٠‬‬

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‫‪@ @@æ…bÈàÜÛ@òîbîÔÛa@‰bjnüa@pbäîÇ@RMSMS‬‬ ‫ﺍﻟﻌﻴﻨﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻻﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﻟﻠﻤﻌﺎﺩﻥ ﺛﻼﺛﺔ ﺃﻧﻮﺍﻉ ﻫﻰ‪:‬‬

‫‪ -١‬‬ ‫ﺗﺴﺘﺨﺪﻡ ﺍﻟﻌﻴﻨﺔ ﺍﻟﻄﻮﻳﻠﺔ ﻋﻨﺪ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﺑﻐﺮﺽ ﺭﺳﻢ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺍﻟﺘـﺸﻜﻞ ﺃﻭ ﻣـﻨﺤﲎ‬ ‫ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺣﱴ ﳝﻜﻦ ﺗﺜﺒﻴﺖ ﻭﺗﺮﻛﻴﺐ ﺃﺟﻬﺰﺓ ﻗﻴﺎﺱ ﺍﻟﺘﺸﻜﻞ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﻛﺬﻟﻚ ﺑﻐﺮﺽ ﺳﻬﻮﻟﺔ‬ ‫ﺗﻌﻴﲔ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻭﻣﻨﻄﻘﺔ ﺍﳋﻀﻮﻉ ﰱ ﺍﻟﻀﻐﻂ‪ .‬ﻭﺍﻟﻨﺴﺒﺔ ﺑﲔ ﺍﻟﻄﻮﻝ ﻭﻗﻄﺮ ﺍﻟﻘﻄﺎﻉ ﻟﻠﻌﻴﻨـﺔ ﺍﻟﻄﻮﻳﻠـﺔ‬ ‫ﻳﻜﻮﻥ ﻛﺎﻵﺗﻰ‪:‬‬ ‫ﺍﻟﻄﻮﻝ = ‪ ١٠ : ٨‬ﺍﻟﻘﻄﺮ‬

‫‪ -٢‬‬ ‫ﺗﺴﺘﺨﺪﻡ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺘﻮﺳﻄﺔ ﻋﻨﺪ ﺗﻌﻴﲔ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻀﻐﻂ ﻟﻠﻤﻌﺎﺩﻥ‪ .‬ﻭﻳﻜﻮﻥ ﻃﻮﻝ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺘﻮﺳـﻄﺔ ﺛـﻼﺙ‬ ‫ﻣﺮﺍﺕ ﻗﻄﺮ ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ‬ ‫ﺍﻟﻄﻮﻝ = ‪ ٣‬ﺍﻟﻘﻄﺮ‬

‫‪ -٣‬‬ ‫ﺍﻟﻌﻴﻨﺔ ﺍﻟﻘﺼﲑﺓ ﺗﺴﺘﺨﺪﻡ ﻻﺧﺘﺒﺎﺭ ﻣﻌﺎﺩﻥ ﺍﳌﺮﺗﻜﺰﺍﺕ ﺣﻴﺚ ﻳﻜﻮﻥ ﺗﺄﺛﲑ ﺍﻻﺣﺘﻜﺎﻙ ﺍﳌﻮﺟﻮﺩ ﻋﻨﺪ ﺳﻄﺤﻲ‬ ‫‪‬ﺎﻳﱴ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻣﺸﺎ‪‬ﺎ ﳊﺎﻟﺔ ﺗﺸﻐﻴﻞ ﻣﻌﺎﺩﻥ ﺍﳌﺮﺗﻜﺰﺍﺕ‪ .‬ﻭﻳﻜﻮﻥ ﻃﻮﻝ ﺍﻟﻌﻴﻨﺔ ﺍﻟﻘـﺼﲑﺓ ﺑﺎﻟﻨـﺴﺒﺔ‬ ‫ﻟﻘﻄﺮﻫﺎ ﻛﻤﺎ ﻳﻠﻰ‪:‬‬ ‫ﺍﻟﻄﻮﻝ = ‪ ٠,٩‬ﺍﻟﻘﻄﺮ‬ ‫‪@ @Nòîã†È½a@Ë@…aìàÜÛ@òîbîÔÛa@‰bjnüa@pbäîÇ@SMSMS‬‬ ‫ﺃﻫﻢ ﺍﳌﻮﺍﺩ ﻏﲑ ﺍﳌﻌﺪﻧﻴﺔ ﺍﻟﱴ ‪‬ﺘﻢ ‪‬ﺎ ﻫﻲ ﺍﳋﺮﺳﺎﻧﺔ ﻭﺍﻟﻌﻴﻨﺔ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻟﻠﺨﺮﺳﺎﻧﺔ ﻋﻤﻮﻣﺎ ﺗﻜﻮﻥ ﺇﺳـﻄﻮﺍﻧﺔ‬ ‫ﻃﻮﳍﺎ ﺿﻌﻒ ﻗﻄﺮﻫﺎ‪ ،‬ﻭ ﻟﻠﺮﻛﺎﻡ ﺍﻟﺬﻯ ﻣﻘﺎﺳﺔ ﻻ ﻳﺘﺠﺎﻭﺯ ‪ ٥٠‬ﻣﻢ ﺗﻜﻮﻥ ﺃﺑﻌﺎﺩ ﺍﻹﺳـﻄﻮﺍﻧﺔ ﺍﻟﻘﻴﺎﺳـﻴﺔ‬ ‫‪٣٠ ×١٥‬ﺳﻢ ﻭﻋﻤﻮﻣﹰﺎ ﻓﺈﻥ ﻗﻄﺮ ﺍﻹﺳﻄﻮﺍﻧﺔ ﳚﺐ ﺃﻥ ﻻ ﻳﻘﻞ ﻋـﻦ ﺛﻼﺛـﺔ ﺃﻣﺜـﺎﻝ ﻣﻘـﺎﺱ ﺍﻟﺮﻛـﺎﻡ‬ ‫ﺍﳌﺴﺘﺨﺪﻡ‪ ٠‬ﻭﺗﻨﺺ ﺍﳌﻮﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﺍﳌﺼﺮﻳﺔ ﻭﻛﺬﻟﻚ ﺍﳌﻮﺻﻔﺎﺕ ﺍﻻﳒﻠﻴﺰﻳﺔ ﻋﻠﻰ ﺍﺳﺘﺨﺪﺍﻡ ﻣﻜﻌﺒﺎﺕ‬ ‫‪ ١٥ × ١٥ ×١٥‬ﺳﻢ ‪ ،‬ﺃﻣﺎ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻷﻣﺮﻳﻜﻴﺔ ﻓﺈ‪‬ﺎ ﺗﻨﺺ ﻏﻠﻰ ﺍﺳﺘﺨﺪﺍﻡ ﻋﻴﻨﺎﺕ ﺍﺳﻄﻮﺍﻧﻴﺔ ﺍﻟﺸﻜﻞ‬ ‫ﻗﻄﺮﻫﺎ ‪١٥‬ﺳﻢ ﻭﺍﺭﺗﻔﺎﻋﻬﺎ ‪ ٣٠‬ﺳﻢ ﻭﺫﻟﻚ ﺣﱴ ﻣﻘﺎﺱ ﺍﻋﺘﺒﺎﺭﻯ ﺃﻛﱪ ﻟﻠﺮﻛﺎﻡ ﺍﳋﺸﻦ ﺣﱴ ‪ ٥٠‬ﻣﻢ‪.‬‬

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‫‪@ @ÁÌšÛa@‰bjna@‹bØm‰a@†ÇaìÓ@TMSMS‬‬ ‫ ﺳﻄﺤﻲ ﺍﻟﺘﺤﻤﻴﻞ ﻟﻔﻜﻲ ﻣﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﰱ ﺍﻟﻀﻐﻂ ﳚﺐ ﺃﻥ ﻳﻜﻮﻧﺎ ﻣﺴﺘﻮﻳﲔ ﻭﻋﻤﻮﺩﻳﻦ ﻋﻠﻰ ﳏـﻮﺭ‬‫ﺍﻟﻌﻴﻨﺔ ﺣﱴ ﻻ ﳛﺪﺙ ﺃﻯ ﺗﺮﻛﻴﺰ ﻏﲑ ﻣﻨﺘﻈﻢ ﻟﻺﺟﻬﺎﺩﺍﺕ ﻋﻠﻰ ﺳﻄﺢ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘـﱪﺓ ﺃﻭ ﺣـﺪﻭﺙ ﺃﻯ‬ ‫ﺍﳓﻨﺎﺀ ﻟﻠﻌﻴﻨﺔ‪ .‬ﻭﻋﻠﻴﻪ ﻓﺈﻧﻪ ﳚﺐ ﺗﺜﺒﻴﺖ ﺍﻟﻌﻴﻨﺔ ﺃﻓﻘﻴﺔ ﲤﺎﻣﺎ ﻭﻋﻤﻮﺩﻳﺔ ﻋﻠﻰ ﳏﻮﺭ ﺍﻟﺘﺤﻤﻴﻞ ﺍﻟﺮﺃﺳﻲ ﻭﺫﻟـﻚ‬ ‫ﻟﻠﻤﻌﺎﺩﻥ ﺍﻟﱴ ﺃﺳﻄﺤﻬﺎ ﻣﻠﺴﺎﺀ ﲤﺎﻣﹸﺎ‪.‬‬ ‫ ﺃﻣﺎ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻌﻴﻨﺎﺕ ﺍﳋﺮﺳﺎﻧﺔ ﺃﻭ ﺍﻟﻌﻴﻨﺎﺕ ﺍﻷﺧﺮﻯ ﻣﻦ ﻃﻮﺏ ﻭﺃﺣﺠﺎﺭ ﻓﻼ ﺑﺪ ﻣﻦ ﻋﻤـﻞ ﻏﻄـﺎﺀ ﺃﻭ‬‫ﳐﺪﺓ ﻟﻠﻌﻴﻨﺔ ﻣﻦ ﻣﻮﻧﺔ ﺃﲰﻨﺘﻴﺔ ﺃﻭ ﻣﻮﻧﺔ ﻻﺋﻘﺔ ﻟﺘﺴﻮﻳﺔ ﺍﻷﺳﻄﺢ ﺍﳋﺸﻨﺔ ﻭﺟﻌﻠﻬﺎ ﻣﻠﺴﺎﺀ ﲝﻴـﺚ ﻳﺘﻘـﺎﺭﺏ‬ ‫ﻣﻘﺎﻭﻣﺘﻬﺎ ﺍﻟﻘﺼﻮﻯ ﻟﻠﻀﻐﻂ ﻣﻊ ﻣﻘﺎﻭﻣﺔ ﺍﳌﺎﺩﺓ ﺍﳌﺨﺘﱪﺓ ﻛﻤﺎ ﺃﻧﻪ ﳝﻜﻦ ﺍﺳﺘﺨﺪﺍﻡ ﺃﻟﻮﺍﺡ ﺍﺭﺗﻜﺎﺯ ﺃﻭ ﳐﺪﺍﺕ‬ ‫ﲢﻤﻴﻞ ﻣﻦ ﻣﺎﺩﺓ ﺗﻜﻮﻥ ﻣﻘﺎﻭﻣﺘﻬﺎ ﺃﻛﱪ ﻣﻦ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻟﻠﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻟـﻀﻤﺎﻥ ﺍﺳـﺘﻮﺍﺀ ﺳـﻄﺢ‬ ‫ﻋﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﻣﻊ ﺍﻻﺗﺰﺍﻥ ﺍﻟﻜﺎﰱ ﻟﻠﻌﻴﻨﺔ ﺧﺎﺻﺔ ﺍﻟﻌﻴﻨﺔ ﺻﻐﲑﺓ ﺍﻟﻘﻄﺮ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻔﻚ ﺍﳌﺎﻛﻴﻨﺔ‪ ،‬ﻭﻛـﺬﻟﻚ‬ ‫ﺿﻤﺎﻥ ﺭﺃﺳﻴﺔ ﺍﻟﺘﺤﻤﻴﻞ ﻻﻧﺘﻘﺎﻝ ﺍﳊﻤﻞ ﻣﻦ ﺍﳌﺎﻛﻴﻨﺔ ﻟﻠﻌﻴﻨﺎﺕ ﺑﺎﻧﺘﻈﺎﻡ ﻭﺃﻳﻀﺎ ﻳﻜﻮﻥ ﻣﺴﻄﺢ ﺍﻧﺘﻘﺎﻝ ﺍﻷﲪﺎﻝ‬ ‫ﻛﺒﲑ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻟﻀﻤﺎﻥ ﺗﻘﻠﻴﻞ ﺍﻻﺟﻬﺎﺩﺍﺕ ﺍﳌﻨﺘﻘﻠﺔ ﻟﻠﻔﻜﲔ‪ ،‬ﻭﺗﻘﻠﻴﻞ ﺍﺣﺘﻤﺎﻝ ﺗﻠﻔﻬﺎ‪.‬‬ ‫ ﻭﻋﺎﺩﺓ ﺗﺮﺗﻜﺰ ﺍﺣﺪﻯ ‪‬ﺎﻳﱵ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻋﻠﻰ ﻗﺎﻋﺪﺓ ﻛﺮﻭﻳﺔ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟـﺸﻜﻞ )‪،(٥-٣‬‬‫ﻭﺍﻟﻐﺮﺽ ﺍﻷﺳﺎﺳﻰ ﻣﻦ ﻫﺬﻩ ﺍﻟﻘﺎﻋﺪﺓ ﺍﻟﻜﺮﻭﻳﺔ ﻫﻮ ﺿﻤﺎﻥ ﺍﻧﻄﺒﺎﻕ ﳏﻮﺭ ﺍﻟﻌﻴﻨﺔ ﻣﻊ ﳏﻮﺭ ﺍﻟﺮﺃﺱ ﳌﺎﻛﻴﻨـﺔ‬ ‫ﺍﻻﺧﺘﺒﺎﺭ ﳑﺎ ﻳﻌﻄﻰ ﺗﻮﺯﻳﻌﺎ ﻣﻨﺘﻈﻤﺎ ﻟﻺﺟﻬﺎﺩﺍﺕ‪ .‬ﻭﻳﻔﻀﻞ ﺃﻥ ﺗﻜﻮﻥ ﺍﻟﻘﺎﻋﺪﺓ ﺍﻟﻜﺮﻭﻳـﺔ ﻋﻠـﻰ ﺍﻟـﺴﻄﺢ‬ ‫ﺍﻟﻌﻠﻮﻯ ﻟﻠﻌﻴﻨﺔ ﺃﻯ ﺑﺎﻟﻔﻚ ﺍﻟﻌﻠﻮﻯ ﳌﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ‪ ،‬ﻭﻟﻜﻰ ﺗﻜﻮﻥ ﳏﺼﻠﺔ ﺍﻟﻘﻮﻯ ﻋﻠﻰ ﺍﻟـﺴﻄﺢ ﺍﶈﻤـﻞ‬ ‫ﻣﺮﻛﺰﺓ ﻣﻊ ﳏﻮﺭ ﺍﻟﻌﻴﻨﺔ‪ ،‬ﻭﺃﻳﻀﺎ ﻣﻦ ﺍﻟﻀﺮﻭﺭﻯ ﺃﻥ ﻳﻜﻮﻥ ﻣﺮﻛﺰ ﺍﻟﺴﻄﺢ ﺍﻟﻜﺮﻭﻯ ﳍﺬﻩ ﺍﻟﻘﺎﻋﺪﺓ ﻣﻨﻄﺒـﻖ‬ ‫ﻋﻠﻰ ﺍﻟﺴﻄﺢ ﺍﻷﻓﻘﻰ ﻟﻠﻌﻴﻨﺔ ﺑﺎﻟﺮﻏﻢ ﻣﻦ ﺟﻌﻞ ﺍﻟﻌﻴﻨﺔ ﳏﻮﺭﻳﺔ ﻣﻊ ﳏﻮﺭ ﺍﻟﻜﺮﺓ‪ ،‬ﻭﺑﺎﻟﻨﺴﺒﺔ ﺇﱃ ﺯﻳﺎﺩﺓ ﻣﻘﺎﻭﻣﺔ‬ ‫ﺍﻻﺣﺘﻜﺎﻙ ﻣﻊ ﺯﻳﺎﺩﺓ ﺍﳊﻤﻞ ﻓﺈﻥ ﺍﻟﻘﺎﻋﺪﺓ ﺍﻟﻜﺮﻭﻳﺔ ﺗﺘﺤﺮﻙ ﻧﺘﻴﺠﺔ ﺍﻻﳓﻨﺎﺀ ﺍﻟﻨﺎﺗﺞ ﻣﻦ ﺍﻟﺘﺤﻤﻴﻞ‪ ،‬ﻛﻤﺎ ﺃﻧـﻪ‬ ‫ﳚﺐ ﺃﻥ ﺗﻜﻮﻥ ﺃﺑﻌﺎﺩ ﻗﺎﻋﺪﺓ ﺍﻻﺭﺗﻜﺎﺯ ﺃﻛﱪ ﻣﻦ ﻗﻄﺮ ﺍﻟﻌﻴﻨﺔ‪.‬‬

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‫‪@ @ÁÌšÛa@‰bjna@õaŠug@òÔíŠ@UMSMS‬‬ ‫ﻗﺒﻞ ﺇﺟﺮﺍﺀ ﺍﻻﺧﺘﺒﺎﺭ ﳚﺐ ﺃﻥ ﺗﻘﺎﺱ ﻋﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﻃﺒﻘﺎ ﻟﻠﻤﻮﺍﺻﻔﺎﺕ ﺍﻟﺘﺎﺑﻌﺔ ﳍﺎ ﻭﺇﺫﺍ ﺍﺣﺘـﺎﺝ ﺍﻷﻣـﺮ‬ ‫ﳌﻌﺮﻓﺔ ﺍﻟﻮﺯﻥ ﺍﳊﺠﻤﻲ ﻟﻠﻤﻮﺍﺩ ﺍﳌﺨﺘﱪﺓ ﳝﻜﻦ ﻭﺯﻥ ﺍﻟﻌﻴﻨﺔ ﲟﻴﺰﺍﻥ ﺣﺴﺎﺱ ﻗﺒﻞ ﺍﻻﺧﺘﺒﺎﺭ‪ .‬ﰒ ﺑﻌـﺪ ﺫﻟـﻚ‬ ‫ﳚﺐ ﺍﻟﻌﻨﺎﻳﺔ ﺑﻮﺿﻊ ﺍﻟﻌﻴﻨﺔ ﰱ ﻣﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﲝﻴﺚ ﺗﻜﻮﻥ ﳏﻮﺭﻳﺔ ﲤﺎﻣﺎ ﺑﻌﺪ ﺗﻨﻈﻴﻒ ﺳـﻄﺤﻲ ﺍﻟﻌﻴﻨـﺔ‬ ‫ﺍﳌﺨﺘﱪﺓ ﻭﻓﻜﻲ ﻣﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻻﺯﺍﻟﺔ ﺃﻯ ﻣﻮﺍﺩ ﻏﺮﻳﺒﺔ ﺃﻭ ﺷﺤﻮﻣﺎﺕ ﺍﻟﱴ ﺗﺆﺛﺮ ﻋﻠﻰ ﺍﻻﺣﺘﻜﺎﻙ ﺍﳌﻮﺟﻮﺩ‬ ‫ﺑﲔ ﺳﻄﺤﻲ ﺍﻟﻌﻴﻨﺔ ﻭﻓﻜﻲ ﺍﳌﺎﻛﻴﻨﺔ‪ .‬ﻭﻳﻔﻀﻞ ﺃﻥ ﻳﻌﺪﻝ ﺍﳉﺰﺀ ﺍﻟﻌﻠﻮﻯ ﻣﻦ ﻟﻮﺡ ﺍﻻﺭﺗﻜﺎﺯ ﺑﺎﻟﻴﺪ ﻋﻨﺪﻣﺎ ﺗﺒﺪﺃ‬ ‫ﻣﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﰱ ﺍﳍﺒﻮﻁ ﻟﺘﻨﻄﺒﻖ ﻣﻊ ﺳﻄﺢ ﺍﻟﻌﻴﻨﺔ ﻭﺫﻟﻚ ﻟﺘﺴﻬﻴﻞ ﺍﺭﺗﻜﺎﺯ ﺟﺰﺀ ﺍﳌﺎﻛﻴﻨﺔ‪.‬‬ ‫ﰒ ﻳﺘﻢ ﺍﻟﺘﺄﺛﲑ ﲝﻤﻞ ﺿﻐﻂ ﺍﺳﺘﺎﺗﻴﻜﻰ ﺑﻄﺊ ﻭﲟﻌﺪﻝ ﺛﺎﺑﺖ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﺣـﱴ ﺍﻟﻜـﺴﺮ‪ ،‬ﻭﻳـﺘﻢ‬ ‫ﺗﺴﺠﻴﻞ ﺗﻠﻚ ﺍﻷﲪﺎﻝ ﺗﺒﺎﻋﹰﺎ ﻣﻦ ﻣﻘﻴﺎﺱ ﺍﳊﻤﻞ ﺑﺎﳌﺎﻛﻴﻨﺔ‪ ،‬ﻭﻛﺬﻟﻚ ﻳﺘﻢ ﺃﻳـﻀﺎ ﺗـﺴﺠﻴﻞ ﺍﻻﻧـﻀﻐﺎﻃﺎﺕ‬ ‫ﺍﳌﻘﺎﺑﻠﺔ ﻟﻜﻞ ﲪﻞ ﻭﺫﻟﻚ ﻟﺴﻬﻮﻟﺔ ﺭﺳﻢ ﻣﻨﺤﻰ ﺍﳊﻤﻞ ﻭﺍﻟﺘﺸﻜﻞ ﻭﻛﺬﻟﻚ ﺗﻮﻗﻴـﻊ ﻣـﻨﺤﲎ ﺍﻹﺟﻬـﺎﺩ‬ ‫ﻭﺍﻻﻧﻔﻌﺎﻝ ﻟﺘﻌﻴﲔ ﻛﻞ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﺍﳌﻄﻠﻮﺑﺔ ﻟﻠﻤﺎﺩﺓ ﺍﳌﺨﺘﱪﺓ ﻭﻛـﺬﻟﻚ ﺍﳊﻜـﻢ ﻋﻠـﻰ ﻣـﺪﻯ‬ ‫ﺻﻼﺣﻴﺘﻬﺎ ﻟﻺﺳﺘﺨﺪﺍﻡ ﰱ ﺍﻷﻏﺮﺍﺽ ﺍﻹﻧﺸﺎﺋﻴﺔ ﻃﺒﻘﺎ ﻟﻠﻤﻮﺍﺻﻔﺎﺕ ﺍﳌﻄﻠﻮﺑﺔ ﻣﻦ ﺃﺟﻠﻬﺎ‪ .‬ﻭﻳﻮﺟـﺪ ﺑﻌـﺾ‬ ‫ﺍﻻﺣﺘﻴﺎﺟﺎﺕ ﺍﻟﻼﺯﻡ ﻣﺮﺍﻋﺘﻬﺎ ﻋﻨﺪ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﻭﻫﻰ ﻛﻤﺎ ﻳﻠﻰ‪:‬‬ ‫‪-١‬‬

‫ﺃﻥ ﻳﻜﻮﻥ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﺻﺤﻴﺤﹰﺎ ﰱ ﺍﻟﻘﻴﻤﺔ ﻭﺍﻻﲡﺎﻩ‪ ،‬ﻷﻧﻪ ﻟﻜﱪ ﻣﺴﺎﺣﺔ ﻓﻜﻰ ﺍﳌﺎﻛﻴﻨﺔ‬ ‫ﺑﺎﻟﻨﺴﺒﺔ ﳌﺴﺎﺣﺔ ﻣﻘﻄﻊ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻓﺈﻥ ﺍﳊﻤﻞ ﺍﳌﻨﺘﻘﻞ ﺇﱃ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻗﺪ ﻳﺘـﺄﺛﺮ ﺑـﺬﻟﻚ‬ ‫ﻭﳝﻜﻦ ﺍﻟﺘﻐﻠﺐ ﻋﻠﻰ ﺫﻟﻚ ﺑﺎﺳﺘﺨﺪﺍﻡ ﳐﺪﺍﺕ ﲢﻤﻴﻞ ﲟﻘﻄﻊ ﺃﻛﱪ ﻣﻦ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺃﻗﻞ ﻣـﻦ‬ ‫ﺳﻄﺢ ﺭﺃﺱ ﺍﳌﺎﻛﻴﻨﺔ ﻟﻜﻰ ﻳﺘﻨﻘﻞ ﺍﳊﻤﻞ ﺻﺤﻴﺤﹰﺎ ﻭﺗﺪﺭﳚﻴﹰﺎ ﺇﱃ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ‪.‬‬

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‫ﳚﺐ ﺃﻥ ﺗﻜﻮﻥ ﺭﺃﺳﻰ ﻣﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﺫﺍﺕ ﻣﺮﺗﻜﺰ ﻛﺮﻭﻯ ﻟﻀﺒﻂ ﺃﻯ ﺍﳓـﺮﺍﻑ ﺑـﲔ ﳏـﻮﺭ‬ ‫ﺍﻟﺘﺤﻤﻴﻞ ﻭﳏﻮﺭ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺃﻥ ﻳﻜﻮﻥ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﺭﺃﺳﻴﺎ ﺩﺍﺋﻤﺎ ﺷﻜﻞ )‪.(٥ -٣‬‬

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‫ﻼ ﻣﻦ ﺳﻄﺤﻲ ‪‬ﺎﻳﱴ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻣﺘﻮﺍﺯﻳﲔ ﻭﻣﺴﺘﻮﻳﲔ ﲤﺎﻣﺎ ﻭﻋﻤﻮﺩﻳﲔ ﻋﻠـﻰ‬ ‫ﳚﺐ ﺟﻌﻞ ﻛ ﹰ‬ ‫ﳏﻮﺭ ﺍﻟﻌﻴﻨﺔ ﻭﻫﺬﺍ ﳚﻌﻞ ﳏﻮﺭ ﺍﻟﻌﻴﻨﺔ ﻳﻨﻄﺒﻖ ﺑﻜﻞ ﺳﻬﻮﻟﺔ ﻋﻠﻰ ﳏﻮﺭ ﺍﳌﺎﻛﻴﻨـﺔ ﳌﻨـﻊ ﻻ ﳏﻮﺭﻳـﺔ‬ ‫ﺍﻟﺘﺤﻤﻴﻞ‪.‬‬

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‫ﳚﺐ ﺃﻥ ﻻ ﻳﺰﻳﺪ ﺍﺭﺗﻔﺎﻉ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻋﻦ ﻋﺸﺮ ﻣﺮﺍﺕ ﻗﻄﺮ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﺴﻄﺢ ﺍﻟﻌﻴﻨﺔ‬ ‫ﳌﻨﻊ ﺣﺪﻭﺙ ﺃﻯ ﺍﻧﺒﻌﺎﺝ ﺟﺎﻧﱯ ﺑﺎﻟﻌﻴﻨﺔ ﺃﺛﻨﺎﺀ ﺍﻻﺧﺘﺒﺎﺭ‪.‬‬

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‫ﺍﻟﺮﺃﺱ ﺍﻟﻌﻠﻮﻱ ﻟﻠﻤﺎﻛﻴﻨﺔ‬

‫ﻛﺮﺳﻲ ﻛﺮﻭﻱ‬ ‫ﺑﻠﻮﻙ ﲢﻤﻴﻞ‬

‫ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ‬

‫ﺑﻠﻮﻙ ﲢﻤﻴﻞ‬

‫ﻗﺎﻋﺪﺓ ﺍﳌﺎﻛﻴﻨﺔ‬

‫‘‪@ @ÁÌšÛa@‰bjnü@‹bØm‰üa@†ÇaìÓ@HUMSI@ÝØ‬‬

‫‪@ @@ÚbØnyüa@qdm@kä£@ÖŠ@VMSMS‬‬ ‫ﻻ ﻳﻮﺟﺪ ﺗﻮﺯﻳﻊ ﻣﻨﺘﻈﻢ ﲤﺎﻣﺎ ﻟﻼﺟﻬﺎﺩﺍﺕ ﻋﻠﻰ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ‪ ،‬ﻭﻳﺮﺟﻊ ﺫﻟﻚ ﺇﱃ‬ ‫ﻭﺟﻮﺩ ﺍﻻﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﻄﺮﻳﺔ ﻭﺍﳌﻤﺎﺳﻴﺔ ﻟﻘﻮﻯ ﺍﻻﺣﺘﻜﺎﻙ ﺑﲔ ﺳﻄﺤﻰ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻭﺑﲔ ﻓﻜﻰ ﻣﺎﻛﻴﻨﺔ‬ ‫ﺍﻻﺧﺘﺒﺎﺭ‪ ،‬ﻭﳚﺐ ﲡﻨﺐ ﻭﺗﻘﻠﻴﻞ ﺍﻻﺣﺘﻜﺎﻙ ﺑﺎﻟﻄﺮﻕ ﺍﻟﺘﺎﻟﻴﺔ‪:‬‬ ‫‪-١‬‬

‫ﺗﺸﺤﻴﻢ ﺍﻻﺳﻄﺢ ﺍﳌﻌﺮﺿﺔ ﻟﻼﺣﺘﻜﺎﻙ ﺑﺎﺳﺘﻌﻤﺎﻝ ﻣﺎﺩﺓ ﻣﻨﺎﺳﺒﺔ ﻟﻠﺘﺸﺤﻴﻢ ﺃﻯ ﺍﻟﺘﺸﺤﻴﻢ ﺑﲔ ﻓﻜﻰ‬ ‫ﺍﳌﺎﻛﻴﻨﺔ ﻭﺳﻄﺤﻰ ﺍﻟﻌﻴﻨﺔ ﻟﺘﺠﻨﺐ ﺍﻟﻘﻮﻯ ﺍﻟﻐﲑ ﻣﺮﻏﻮﺏ ﻓﻴﻬﺎ ﻭﻣﺴﺒﺒﺔ ﻟﻺﺣﺘﻜﺎﻙ‪.‬‬

‫‪-٢‬‬

‫ﺍﻗﺘﺮﺍﺡ ﻃﺮﻳﻘﺔ ﻟﻠﺤﺼﻮﻝ ﻋﻠﻰ ﺗﺸﻜﻞ ﻣﻨﺘﻈﻢ ﺑﻌﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺫﻟﻚ ﺑﺘﻘﺴﻴﻢ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﺇﱃ‬ ‫ﺛﻼﺛﺔ ﺃﺟﺰﺍﺀ ﻭﺑﺬﻟﻚ ﻳﻨﺘﻈﻢ ﺍﻟﺘﻐﲑ ﰱ ﺷﻜﻞ ﺍﳉﺰﺀ ﺍﻷﻭﺳﻂ ﻣﻦ ﺍﻟﻌﻴﻨﺔ‪ ،‬ﻭﺗﺘﺒﻊ ﻫﺬﻩ ﺍﻟﻄﺮﻳﻘﺔ ﰱ‬ ‫ﺍﳌﻮﺍﺩ ﺫﺍﺕ ﺍﻟﺘﻐﲑ ﺍﻟﻘﻠﻴﻞ ﰱ ﺍﻟﺸﻜﻞ‪.‬‬

‫‪-٣‬‬

‫ﳝﻜﻦ ﺗﻘﻠﻴﻞ ﻻﺣﺘﻜﺎﻙ ﲜﻌﻞ ﺭﺃﺱ ﻣﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﲝﻴﺚ ﲤﻴﻞ ﻋﻠﻰ ﺳﻄﺤﻰ ﺍﻟﻌﻴﻨـﺔ ﺍﳌﺨﺘـﱪﺓ‬ ‫ﺑﺰﺍﻭﻳﺔ ﻣﻘﺪﺍﺭﻫﺎ ﻳﺴﺎﻭﻯ ﺯﺍﻭﻳﺔ ﺍﻻﺣﺘﻜﺎﻙ ﺑﲔ ﺳﻄﺤﻰ ﺍﻟﻌﻴﻨﺔ ﻭﻓﻜﻰ ﺍﳌﺎﻛﻴﻨﺔ‪ .‬ﻭﺑﺬﻟﻚ ﻳﺘـﻮﺍﺯﻯ‬ ‫ﺍﲡﺎﻩ ﺍﻻﺟﻬﺎﺩﺍﺕ ﻣﻊ ﳏﻮﺭ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻭﲢﺘﻔﻆ ﺑﺸﻜﻠﻬﺎ ﺍﻻﺳﻄﻮﱏ ﺑﻌﺪ ﺍﻻﺧﺘﺒـﺎﺭ‪ ،‬ﻭﻟﻜـﻦ‬ ‫ﺍﻟﻌﻴﺐ ﺍﻟﻮﺣﻴﺪ ﰱ ﻫﺬﻩ ﺍﻟﻄﺮﻳﻘﺔ ﻫﻮ ﻋﺪﻡ ﺗﺴﺎﻭﻯ ﺗﻮﺯﻳﻊ ﺍﻻﻧﻔﻌﺎﻝ ﻋﻠﻰ ﻣﻘﻄﻊ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘـﱪﺓ‬ ‫ﻭﳝﻜﻦ ﺍﳘﺎﻝ ﺫﻟﻚ ﻟﻮ ﺻﻐﺮﺕ ﻗﻴﻤﺔ ﺯﺍﻭﻳﺔ ﺍﳌﻴﻞ ﻟﺘﻜﻮﻥ ﺑﻘﻴﻤﺔ ﺗﺘﺮﻭﺍﺡ ﻣﺎ ﺑﲔ ‪ ١٤-٣‬ﺩﺭﺟـﺔ‬ ‫ﻭﳝﻜﻦ ﺍﻳﻀﺎ ﺑﺪﻫﺎﻥ ﻭﺗﺸﺤﻴﻢ ﺳﻄﺤﻰ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ‪.‬‬

‫‪٧١‬‬


‫‪ &'( #) *! ,- #.$ 4-3‬‬

‫‪@ @òÜîĐ½a@æ…bÈ½a@óÏ@‰bîèãüa@QMTMS‬‬ ‫ﻧﻼﺣﻆ ﺃﻥ ﺍﻟﻌﻴﻨﺎﺕ ﺍﳌﺨﺘﱪﺓ ﻣﻦ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﲢﺖ ﺗﺄﺛﲑ ﺃﲪﺎﻝ ﺍﻟﻀﻐﻂ ﻻ ﳛﺪﺙ ﳍﺎ ﻛﺴﺮ ﻷ‪‬ـﺎ‬ ‫ﺗﺘﻔﻠﻄﺢ ﺑﺎﻟﻀﻐﻂ ﻭﲢﺎﻓﻆ ﺍﻟﻌﻴﻨﺔ ﻋﻠﻰ ﺯﻳﺎﺩﺓ ﺗﻔﻠﻄﺤﻬﺎ ﺍﻻﺳﻄﻮﺍﱏ ﻣﻊ ﺯﻳﺎﺩﺓ ﺃﲪﺎﻝ ﺍﻟﻀﻐﻂ ﻭﻟﻜـﻦ‬ ‫ﳛﺪﺙ ﺍﻻ‪‬ﻴﺎﺭ ﺑﺎﻟﺘﺸﻘﻖ ﺣﻴﺚ ﺗﻈﻬﺮ ﺷﺮﻭﺥ ﺳﻄﺤﻴﺔ ﺭﺃﺳﻴﺔ ﻣﺘﻮﺍﺯﻳﺔ ﻣﻊ ﳏﻮﺭ ﺍﻟﺘﺤﻤﻴﻞ ﻟﻠﻌﻴﻨﺔ ﻛﻤـﺎ‬ ‫ﻫﻮ ﻣﻮﺿﺢ ﺑﺸﻜﻞ )‪ (٦-٣‬ﻭﻳﺘﻮﻗﻒ ﻇﻬﻮﺭ ﻫﺬﻩ ﺍﻟﺸﺮﻭﺥ ﺍﻟﺮﺃﺳﻴﺔ ﻋﻠﻰ ﻣـﺪﻯ ﻣﺮﻭﻧـﺔ ﺍﳌﻌـﺪﻥ‬ ‫ﻭﳑﻄﻮﻟﻴﺘﻪ ﺃﻳﻀﺎ ﻋﻠﻰ ﻣﺪﻯ ﻗﺎﺑﻠﻴﺔ ﺍﳌﻌﺪﻥ ﻟﻠﺴﺤﺐ ﻭﺍﻟﻄﺮﻕ ﻭﲢﻤﻠﻪ ﻟﻺﺟﻬﺎﺩﺍﺕ ﺍﻟﻌﺎﻟﻴﺔ ﻓﻮﻕ ﺣـﺪ‬ ‫ﺍﳌﺮﻭﻧﺔ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻀﻐﻂ ﻭﻳﻌﺘﱪ ﻇﻬﻮﺭ ﺍﻟﺘﺸﻘﻘﺎﺕ ﻭﻗﻴﻤﺔ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻫﻮ ﺩﻟﻴﻞ ﻋﻠـﻰ ﻗﺒـﻮﻝ ﺃﻭ‬ ‫ﺭﻓﺾ ﺍﻟﻌﻴﻨﺎﺕ ﺍﳌﻄﻴﻠﺔ ﺍﳌﺨﺘﱪﺓ‪.‬‬ ‫ﻓﻚ ﺍﳌﺎﻛﻴﻨﺔ ﺍﻟﻌﻠﻮﻱ‬

‫ﻣﺎﺩﺓ ﻣﻄﻴﻠﺔ‬

‫ﺍﻟﻌﻴﻨﺔ ﺍﻷﺻﻠﻴﺔ ﻗﺒﻞ ﺍﻟﺘﺤﻤﻴﻞ‬

‫‪Ductile Material‬‬ ‫ﻣﺜﻞ ﺍﻟﺼﻠﺐ ﺍﻟﻄﺮﻱ‬

‫ﺍﻟﻌﻴﻨﺔ ﺑﻌﺪ ﺍﻟﺘﺤﻤﻴﻞ‬

‫ﺍﻟﺴﻔﻠﻲ @‬ ‫ﻓﻚ ﺍﳌﺎﻛﻴﻨﺔ @‬ ‫@@‬ ‫‘‪@ @òÜîĐ½a@æ…bÈàÜÛ@‰bîèãüa@ÝØ‘@HVMSI@ÝØ‬‬

‫‪@ @@òÐ–ÔÛaë@òÜîĐß@Ñ–äÛa@æ…bÈ½a@óÏ@‰bîèãüa@RMTMS‬‬ ‫ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﻤﻌﺎﺩ ﺍﻟﻨﺼﻒ ﻣﻄﻴﻠﺔ ﳛﺪﺙ ﺍﻧﻀﻐﺎﻁ ﳍﺬﻩ ﺍﳌﻌﺎﺩﻥ ﲢﺖ ﺗﺄﺛﲑ ﺃﲪﺎﻝ ﺍﻟﻀﻐﻂ ﺣﺴﺐ ﻗﻴﻤـﺔ‬ ‫ﺍﳌﻤﻄﻮﻟﻴﺔ ﻭﻣﺮﻭﻧﺔ ﺍﳌﻌﺪﻥ ﰒ ﳛﺪﺙ ﺍﻻ‪‬ﻴﺎﺭ ﻋﻠﻰ ﻣﺴﺘﻮﻳﺎﺕ ﻣﺎﺋﻠﺔ ﺑﺰﺍﻭﻳﺔ ﲤﻴﻞ ﻋﻠﻰ ﺍﻷﻓﻘﻰ ﺗﺘﻮﻗـﻒ‬ ‫ﻗﻴﻤﺘﻬﺎ ﻋﻠﻰ ﻗﻴﻤﺔ ﺯﺍﻭﻳﺔ ﺍﻻﺣﺘﻜﺎﻙ ﺍﻟﺪﺍﺧﻠﻰ ﺑﲔ ﺟﺰﻳﺌﺎﺕ ﺍﳌﻌﺪﻥ ﻭﺍﻟﱴ ﺗﺰﺩﺍﺩ ﻗﻴﻤﺘﻬﺎ ﺑﺰﻳﺎﺩﺓ ﺣﺠـﻢ‬ ‫ﺍﳉﺰﻳﺌﺎﺕ ﺑﺎﳌﻌﺪﻥ ﺍﳌﺨﺘﱪ ﻭﻗﺪ ﺗﻈﻬﺮ ﺑﻌﺾ ﺍﻟﺘﺸﻘﻘﺎﺕ ﺍﻟﺴﻄﺤﻴﺔ ﻗﺒﻞ ﺍﻻ‪‬ﻴﺎﺭ ﻛﻤﺎ ﳛﺪﺙ ﰱ ﺍﳌﻌﺎﺩﻥ‬ ‫ﺍﳌﻄﻴﻠﺔ ‪.‬ﺃﻣﺎ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﻤﻌﺎﺩﻥ ﺍﻟﻘﺼﻔﺔ ﻓﻴﺤﺪﺙ ﺍﻧﻀﻐﺎﻁ ﺑﺴﻴﻂ ﺟﺪﺍ ﰒ ﳛﺪﺙ ﺍﻟﻜﺴﺮ ﻋﻠﻰ ﻣﺴﺘﻮﻯ‬ ‫ﳝﻞ ﺑﺰﺍﻭﻳﺔ )‪ (θ‬ﻣﻊ ﺍﳌﺴﺘﻮﻯ ﺍﻷﻓﻘﻰ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺸﻜﻞ )‪ (٧-٣‬ﻭﺗﺰﺩﺍﺩ ﻫﺬﻩ ﺍﻟﺰﺍﻭﻳـﺔ ﻋـﻦ‬ ‫ﻣﺜﻴﻠﺘﻬﺎ ﰱ ﺍﳌﻮﺍﺩ ﺍﻟﻨﺼﻒ ﻣﻄﻴﻠﺔ ﻟﻜﱪ ﺟﺰﻳﺌﺎﺕ ﺍﳌﻌﺪﻥ ﻭﻻ ﺗﻈﻬﺮ ﺃﻯ ﺗـﺸﻘﻘﺎﺕ ﺑـﺴﻄﺢ ﺍﻟﻌﻴﻨـﺔ‬ ‫ﺍﳌﺨﺘﱪﺓ ﻗﺒﻞ ﺍﻟﻜﺴﺮ‪.‬‬

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‫ﻓﻚ ﺍﳌﺎﻛﻴﻨﺔ ﺍﻟﻌﻠﻮﻱ‬

‫ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ ﰱ ﺍﻟﻘﺺ‬

‫ﺍﻟﻌﻴﻨﺔ ﺍﻷﺻﻠﻴﺔ ﻗﺒﻞ ﺍﻟﺘﺤﻤﻴﻞ‬

‫ﻣﺎﺩﺓ ﻗﺼﻔﺔ‬

‫ﺍﻟﻌﻴﻨﺔ ﺑﻌﺪ ﺍﻟﺘﺤﻤﻴﻞ‬

‫‪Brittle Material‬‬ ‫ﻣﺜﻞ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ‬

‫ﻓﻚ ﺍﳌﺎﻛﻴﻨﺔ ﺍﻟﺴﻔﻠﻲ‬

‫@@‬ ‫‘‪@ @@òÐ–ÔÛa@æ…bÈàÜÛ@‰bîèãüa@ÝØ‘@HWMSI@ÝØ‬‬

‫ﻭﺯﺍﻭﻳﺔ ﻣﻴﻞ ﺍﻟﻜﺴﺮ ﻟﻠﻌﻴﻨﺎﺕ ﺍﻟﻨﺼﻒ ﻣﻄﻴﻠﺔ ﺃﻭ ﺍﻟﻘﺼﻔﺔ ﺍﳌﻨﻬﺎﺭﺓ ﺃﻛﱪ ﻣﻦ ‪ ٤٥‬ﺩﺭﺟﺔ ﻭﻫـﺬﻩ ﺍﻟﺰﺍﻭﻳـﺔ‬ ‫ﺗﺴﺎﻭﻯ‪ θ = 45 + φ /2 :‬ﺣﻴﺚ )‪ (φ‬ﻋﺒﺎﺭﺓ ﻋﻦ ﺯﺍﻭﻳﺔ ﺍﻻﺣﺘﻜﺎﻙ ﺍﻟﺪﺍﺧﻠﻰ ﻟﻠﻤﻌـﺪﻥ ﺍﳌﺨﺘـﱪ‪.‬‬ ‫ﻭﺑﺬﻟﻚ ﺗﻜﻮﻥ ﺯﺍﻭﻳﺔ ﺍﻻﺣﺘﻜﺎﻙ )‪ (φ‬ﻛﺒﲑﺓ ﻣﻊ ﻛﱪ ﺟﺰﻳﺌﺎﺕ ﺍﳌﻌﺪﻥ ﺍﳌﺨﺘﱪ‪ ،‬ﻓﻤـﺜﻼ ﺍﳊﺪﻳـﺪ ﺍﻟﺰﻫـﺮ‬ ‫ﻛﻤﺎﺩﺓ ﻗﺼﻔﺔ ﺯﺍﻭﻳﺔ ﺍﺣﺘﻜﺎﻛﻪ ﺍﻟﺪﺍﺧﻠﻴﺔ ﻛﺒﲑﺓ ﺍﺫﺍ ﻣﺎ ﻗﻮﺭﻧﺖ ﺑﺰﺍﻭﻳﺔ ﺍﻻﺣﺘﻜﺎﻙ ﻟﻠﻨﺤﺎﺱ ﺍﻷﺻﻔﺮ ﻛﻤﺎﺩﺓ‬ ‫ﻧﺼﻒ ﻣﻄﻴﻠﺔ ﺣﻴﺚ ﺃﻥ ﺟﺰﻳﺌﺎﺗﻪ ﺃﺩﻕ ﻣﻦ ﺟﺰﻳﺌﺎﺕ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ‪ .‬ﻭﻗﺪ ﻭﺟﺪ ﺃﻥ ﺯﺍﻭﻳﺔ ﻣﻴـﻞ ﺍﻟﻜـﺴﺮ‬ ‫ﻟﻠﺤﺪﻳﺪ ﺍﻟﺰﻫﺮ = ‪٦٠‬‬ ‫ﺍﻟﻌﻼﻗﺔ‬ ‫‪-١‬‬

‫‪٥‬‬

‫ﰱ ﺣﲔ ﺃﻥ ﺯﺍﻭﻳﺔ ﻣﻴﻞ ﺍﻟﻜﺴﺮ ﻟﻠﻨﺤﺎﺱ ﺍﻷﺻﻔﺮ = ‪ ٥ ٥٠‬ﻭﳝﻜـﻦ ﺍﺛﺒـﺎﺕ‬

‫‪ θ = 45 + φ/2‬ﺑﻄﺮﻳﻘﺘﲔ ﳐﺘﻠﻔﺘﲔ ﻛﻤﺎ ﻳﻠﻲ‪:‬‬ ‫‪ZòÜîÜznÛa@òÔíŠĐÛa‬‬

‫ﺍﻟﻌﻴﻨﺔ ﺍﳌﺒﻴﻨﺔ ﺑﺎﻟﺸﻜﻞ )‪ (٨-٣‬ﻣﺴﺎﺣﺔ ﻣﻘﻄﻌﻬﺎ = ‪ A‬ﻛﺴﺮﺕ ﺑﺘﺄﺛﲑ ﲪﻞ ﺿﻐﻂ )‪ (P‬ﺍﻟﺬﻱ ﺃﺣﺪﺙ ‪‬ﺎ‬ ‫ﺇﺟﻬﺎﺩﹰﺍ ﻗﻴﻤﺘﻪ )‪ (σ‬ﻋﻠﻰ ﻣﺴﺘﻮﻯ ﻳﻌﻤﻞ ﺯﺍﻭﻳﺔ ﻣﻘﺪﺍﺭﻫﺎ )‪ (θ‬ﻣﻊ ﺍﻷﻓﻘﻰ‪ .‬ﻭﻛﺎﻧﺖ ﺍﻟﺰﺍﻭﻳـﺔ )‪ (φ‬ﲤﺜـﻞ‬ ‫ﺯﺍﻭﻳﺔ ﺍﻻﺣﺘﻜﺎﻙ ﺍﻟﺪﺍﺧﻠﻲ ﻟﻠﻤﻌﺪﻥ ﺍﳌﺨﺘﱪ ﻭﻫﻰ ﺭﻗﻢ ﺛﺎﺑﺖ ﻟﻠﻤﻌﺪﻥ ﺍﻟﻮﺍﺣﺪ‪.‬‬ ‫ﺣﻴﺚ ﺇﺟﻬﺎﺩ ﺍﻟﻀﻐﻂ ﺍﻷﻓﻘﻰ = ‪P/A = σ‬‬ ‫ﻭﻣﺴﺎﺣﺔ ﻣﻘﻄﻊ ﺍﻟﻌﻴﻨﺔ ﻋﻠﻰ ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ ) ‪ (B‬ﺣﻴﺚ ‪B=A/Cos θ :‬‬

‫ﻭﺍﻟﻘﻮﺓ )‪ (P‬ﺍﶈﺪﺛﺔ ﻟﻠﻜﺴﺮ ﰱ ﺍﻟﻀﻐﻂ ﺗﺆﺛﺮ ﻋﻠﻰ ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ ﲝﺎﻟﺘﲔ ﺍﺣـﺪﺍﳘﺎ ﻋﻤﻮﺩﻳـﺔ ﻋﻠـﻰ‬ ‫ﺍﳌﺴﺘﻮﻯ )‪ (N‬ﻭﺍﻷﺧﺮﻯ ﻣﻮﺍﺯﻳﺔ ﳌﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ )‪ (Q‬ﻭﻗﻴﻤﺔ ﻛﻞ ﻣﻨﻬﻤﺎ‪:‬‬ ‫‪N = P. Cos θ ,‬‬

‫‪Q = P. Sin θ‬‬

‫‪٧٣‬‬


‫ﻣﺴﺘﻮﻯ ﺍﻻ‪‬ﻴﺎﺭ‬

‫ﲪﻞ ﺍﻟﻀﻐﻂ )‪(P‬‬

‫ﲪﻞ ﻋﻤﻮﺩﻱ‬

‫ﲪﻞ ﻣﻮﺍﺯﻱ‬ ‫‪Q=P Sin θ‬‬

‫‪N=P Cos θ‬‬

‫‪θ‬‬

‫ﻗﻮﺓ ﺍﻻﺣﺘﻜﺎﻙ‬ ‫‪F= N tan φ‬‬

‫‪θ‬‬

‫‘‪@ @ÁÌšÛa@óÏ@òÐ–ÔÛaë@òÜîĐß@Ñ–äÛa@æ…bÈàÜÛ@ôìnß@Ýîß@òíëa‹@HXMSI@ÝØ‬‬

‫ﻭﻫﻨﺎ ﻳﻜﻮﻥ ﺍﻻﺟﻬﺎﺩ ﺍﻟﻌﻤﻮﺩﻯ ﻋﻠﻰ ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ )‪= (σA‬‬

‫ﺍﳊﻤﻞ ﺍﻟﻌﻤﻮﺩﻯ‬ ‫ﻣﺴﺎﺣﺔ ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ‬

‫‪P‬‬ ‫‪P. Cos θ‬‬ ‫‪N‬‬ ‫‪2‬‬ ‫‪2‬‬ ‫=‬ ‫=‬ ‫‪.‬‬ ‫‪Cos‬‬ ‫‪θ‬‬ ‫=‬ ‫‪σ‬‬ ‫‪.‬‬ ‫‪Cos‬‬ ‫‪θ‬‬ ‫‪A‬‬ ‫‪/Cos‬‬ ‫‪θ‬‬ ‫‪A‬‬ ‫‪B‬‬ ‫ﻭﺃﻳﻀﺎ ﻳﻜﻮﻥ ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﺍﻟﺬﻯ ﻣﻊ ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ ) ‪= ( q‬‬

‫= ‪σn‬‬

‫ﺍﳊﻤﻞ ﺍﳌﻮﺍﺯﻯ‬ ‫ﻣﺴﺎﺣﺔ ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ‬

‫‪. Sin θ . Cos θ = σ. Sin θ .Cos θ‬‬

‫‪P‬‬ ‫‪A‬‬

‫‪P. Sin θ‬‬ ‫= ‪A /Cos θ‬‬

‫‪Q‬‬ ‫=‪B‬‬

‫=‪q‬‬

‫ﻛﻤﺎ ﺃﻥ ﺍﻹﺟﻬﺎﺩ ﺍﻟﻌﻤﻮﺩﻯ ﻋﻠﻰ ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ ﻳﺴﺒﺐ ﺇﺟﻬﺎﺩ ﺍﺣﺘﻜﺎﻙ ﻋﻜﺲ ﺇﲡﺎﻩ ﺍﳊﺮﻛـﺔ ﻋﻠـﻰ‬ ‫ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ ﺃﻳﻀﺎ‪ .‬ﻭﺣﻴﺚ ﺃﻥ‪:‬‬

‫‪F‬‬ ‫‪N‬‬

‫= ‪tan φ‬‬

‫‪F = N. tan φ‬‬ ‫ﺇﺫﻥ ﺇﺟﻬﺎﺩ ﺍﻻﺣﺘﻜﺎﻙ )‪= (σf‬‬

‫ﻗﻮﻯ ﺍﻻﺣﺘﻜﺎﻙ‬ ‫ﻣﺴﺎﺣﺔ ﻣﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ‬

‫‪٧٤‬‬


‫‪σ. Cos2 θ. tan φ‬‬

‫=‬

‫‪P .Cos2 θ .tan φ‬‬ ‫‪A‬‬

‫=‬

‫‪N. tan φ‬‬ ‫‪A /Cos θ‬‬

‫=‬

‫‪F‬‬ ‫‪B‬‬

‫=‬

‫‪σf‬‬

‫ﻭﻳﺘﺒﲔ ﳑﺎ ﺳﺒﻖ ﻭﻣﻦ ﺍﻟﺸﻜﻞ )‪ (٨-٣‬ﺃﻥ ﺍﻻﺟﻬﺎﺩﺍﺕ ﺍﳌﺴﺒﺒﺔ ﻟﻠﻜﺴﺮ ﻋﻠﻰ ﺍﳌﺴﺘﻮﻯ ﺍﻟﺬﻯ ﻳﻌﻤﻞ ﺯﺍﻭﻳﺔ‬ ‫)‪ (θ‬ﻣﻊ ﺍﳌﺴﺘﻮﻯ ﺍﻷﻓﻘﻰ )‪ (σr‬ﻫﻰ ﻧﺘﻴﺠﺔ ﻓﺮﻕ ﺗﺄﺛﲑ ﺍﻹﺟﻬﺎﺩ ﺍﳌﻮﺍﺯﻯ ﳌﺴﺘﻮﻯ ﺍﻟﻜﺴﺮ ﺍﻟﻨﺎﺗﺞ ﻣﻦ ﺍﻟﻘﻮﺓ‬ ‫ﺍﻟﺮﺃﺳﻴﺔ )‪ (P‬ﻭﺗﺄﺛﲑ ﺇﺟﻬﺎﺩ ﺍﻻﺣﺘﻜﺎﻙ ﺍﳊﺎﺩﺙ ﻧﺘﻴﺠﺔ ﻣﻘﺎﻭﻣﺔ ﲤﺎﺳﻚ ﺟﺰﻳﺌﺎﺕ ﺍﳌﻌﺪﻥ ﺃﻯ ﺃﻥ‪:‬‬ ‫ﺍﻹﺟﻬﺎﺩ ﺍﳊﺪﺙ ﻟﻠﻜﺴﺮ )‪ = (σr‬ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ) ‪ – (q‬ﺇﺟﻬﺎﺩ ﺍﻻﺣﺘﻜﺎﻙ )‪(σf‬‬ ‫‪q – σf = σ . Sin θ. Cos θ - σ Cos2 θ .tan φ‬‬

‫ﻭﳛﺪﺙ ﺍﻟﻜﺴﺮ ﻋﻨﺪﻣﺎ ﺗﻜﻮﻥ )‪ (σr‬ﺫﺍﺕ ﻗﻴﻤﺔ ﻗﺼﻮﻯ ﺃﻯ ﻋﻨﺪﻣﺎ ﺗﻜﻮﻥ‬ ‫‪=0‬‬

‫= ‪σr‬‬

‫‪d σr‬‬ ‫‪dθ‬‬ ‫‪i.e.‬‬

‫‪Cos2θ - Sin2θ + 2 tan φ . Sinθ . Cosθ = 0‬‬ ‫‪tan φ = - (Cos2θ - Sin2θ) / 2 Sinθ . Cosθ‬‬ ‫‪tan φ = - Cos2θ / Sin2θ) = - Cot 2θ‬‬ ‫)‪tan φ = - tan (90o - 2θ) = tan (2θ – 90o‬‬

‫‪φ = 2θ – 90o‬‬ ‫‪θ = 45o + φ /2‬‬

‫‪-٢‬‬

‫‪@ @òîãbîjÛa@òÔíŠĐÛa‬‬

‫ﻫﺬﻩ ﺍﻟﻄﺮﻳﻘﺔ ﺧﺎﺻﺔ ﺑﺎﳌﻮﺍﺩ ﺍﻟﱴ ﻳﻜﻮﻥ ﺍ‪‬ﻴﺎﺭﻫﺎ ﻧﺘﻴﺠﺔ ﺍﻻﺣﺘﻜﺎﻙ ﺍﻟﺪﺍﺧﻠﻰ ﻭﺍﻟﺘﻤﺎﺳﻚ ﺑـﲔ ﻣﻜﻮﻧـﺎﺕ‬ ‫ﺍﻟﻌﻴﻨﺔ ﻭﺍﻟﱴ ﺗﻮﺍﻓﻖ ﻧﻈﺮﻳﺔ )ﻣﻮﺭ(‪ ،‬ﻭﻣﻨﻬﺎ ﻳﺘﻀﺢ ﺃﻥ ﺯﺍﻭﻳﺔ ﺍﻟﻜﺴﺮ ﺃﻭ ﺯﺍﻭﻳﺔ ﻣﻴﻞ ﻣﺴﺘﻮﻯ ﺃﻗﺼﻰ ﺇﺟﻬـﺎﺩ‬ ‫ﻗﺺ )‪ (θ‬ﻟﻴﺴﺖ ‪ ٤٥‬ﻭﻟﻜﻨﻬﺎ ﺗﺘﻮﻗﻒ ﻋﻠﻰ ﺯﺍﻭﻳﺔ ﺍﻻﺣﺘﻜﺎﻙ ﺍﻟﺪﺍﺧﻠﻴﺔ )‪ .(φ‬ﻭﺍﻟﺸﻜﻞ )‪ (٩-٣‬ﻳﻮﺿﺢ‬ ‫ﺩﺍﺋﺮﺓ ﻣﻮﺭ ﻟﻌﻴﻨﺔ ﻣﻌﺮﺿﺔ ﻹﺟﻬﺎﺩﺍﺕ ﻣﻨﺘﻈﻤﺔ‪ .‬ﺣﻴﺚ ﻳﺘﻢ ﺗﻮﻗﻴﻊ ﳏـﻮﺭﻳﲔ ﻣﺘﻌﺎﻣـﺪﻳﻦ ﺍﶈـﻮﺭ ﺍﻷﻓﻘـﻰ‬ ‫ﻟﻺﺟﻬﺎﺩﺍﺕ ﺍﳌﺘﻌﺎﻣﺪﺓ ﻭﺍﶈﻮﺭ ﺍﻟﺮﺃﺳﻰ ﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﺺ‪ ،‬ﻭﻳﺘﻢ ﺭﺳﻢ ﺩﺍﺋﺮﺓ ﻗﻄﺮﻫﺎ ﻳﺴﺎﻭﻯ ﺃﻗﺼﻰ ﺇﺟﻬﺎﺩ‬ ‫ﻣﺆﺛﺮ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ) ‪ ،( σmax= P‬ﰒ ﻧﺄﺧﺬ ﳑﺎﺱ ﻟﻠﺪﺍﺋﺮﺓ ﳝﻴﻞ ﻋﻠﻰ ﺍﶈﻮﺭ ﺍﻷﻓﻘـﻰ ﺑﺰﺍﻭﻳـﺔ‬ ‫ﺍﻻﺣﺘﻜﺎﻙ )‪.(φ‬‬

‫‪A‬‬

‫‪٧٥‬‬


‫‪Shear Stress‬‬

‫ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ‬

‫ﺣﺪﻭﺩ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻘﺺ‬

‫‪90ο‬‬ ‫‪2θ‬‬

‫‪α‬‬

‫‪2α‬‬ ‫‪o‬‬

‫ﺍﻹﺟﻬﺎﺩ ﺍﻟﻌﻤﻮﺩﻱ‬

‫‪φ‬‬

‫‪θ‬‬

‫‪2α + φ = 90‬‬ ‫‪α = 45- φ/2‬‬

‫‪Normal Stress‬‬

‫‪θ = 90 - α = 45 + φ/2‬‬

‫‪σmax‬‬

‫‘‪@ @ÚbØnyüa@òíëa‹ë@ŠØÛa@òíëa‹@í@òÓýÈÛa@´îÈnÛ@òîãbîjÛa@‰ìß@ñŠöa…@òÔíŠ@HYMSI@ÝØ‬‬

‫ﻭﻣﻦ ﻫﻨﺪﺳﺔ ﺍﻟﺸﻜﻞ ﺍﳌﻮﺿﺢ )‪ (٩-٣‬ﻓﺈﻥ‪-:‬‬ ‫‪θ = 45o + φ /2‬‬ ‫‪α = 45o - φ /2‬‬

‫ﻭﻫﺬﻩ ﺍﻟﻨﻈﺮﻳﺔ ﻻ ﺗﻌﻄﻲ ﻧﺘﺎﺋﺞ ﺻﺤﻴﺤﺔ ﲤﺎﻣﺎ ﺑﺎﻟﻨﺴﺒﺔ ﻟﺒﻌﺾ ﺍﳌﻮﺍﺩ ﻣﺜﻞ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ ﺃﻭ ﺍﳋﺮﺳـﺎﻧﺔ ﺃﻭ‬ ‫ﺍﻟﺴﲑﺍﻣﻴﻚ ﺣﻴﺚ ﺃﻥ ﻋﺪﻡ ﺍﻟﺘﺠﺎﻧﺲ ﰱ ﻫﺬﻩ ﺍﳌﻮﺍﺩ ﻗﺪ ﻻ ﻳﻌﻄﻲ ﺇﺟﻬﺎﺩﺍﺕ ﻣﻨﺘﻈﻤﺔ‪ ،‬ﻭﺯﻳﺎﺩﺓ ﻋﻠﻰ ﺫﻟـﻚ‬ ‫ﻓﺈﻥ ﺯﺍﻭﻳﺔ ﺍﻟﻜﺴﺮ ﳝﻜﻦ ﺃﻥ ﺗﺘﻐﲑ ﻋﻦ ﺍﻟﻘﻴﻤﺔ ﺍﻟﻨﻈﺮﻳﺔ ﻧﺘﻴﺠﺔ ﻟﻼﺟﻬﺎﺩﺍﺕ ﺍﳌﺮﻛﺒﺔ‪٠‬‬ ‫*********‬

‫‪٧٦‬‬


‫ ‬ ‫ ء ‬ ‫‪ 1-4‬‬

‫ﺇﺫﺍ ﺗﻌﺮﺽ ﺃﻯ ﻋﻨﺼﺮ ﺇﻧﺸﺎﺋﻲ ﺇﱃ ﻗﻮﺓ ﺃﻭ ﺃﲪﺎﻝ ﺃﻭ ﻋﺰﻭﻡ ﲝﻴﺚ ﻳﺘﻮﻟﺪ ﻋﻨﻬﺎ ﺇﺟﻬﺎﺩﺍﺕ ﺷﺪ ﻋﻠﻰ ﺃﺣـﺪ‬ ‫ﺃﻭﺟﻪ ﺍﻟﻌﻨﺼﺮ ﻭﺇﺟﻬﺎﺩﺍﺕ ﺿﻐﻂ ﻋﻠﻰ ﺍﻟﻮﺟﻪ ﺍﳌﻘﺎﺑﻞ ﻟﻪ ﻓﺈﻥ ﺍﻟﻌﻨﺼﺮ ﻳﻜﻮﻥ ﰱ ﺣﺎﻟﺔ ﺍﳓﻨﺎﺀ‪ ،‬ﻭﻗﺪ ﲤﺮ ﻗﻴﻤﺔ‬ ‫ﻫﺬﻩ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺑﺎﻟﻘﻴﻤﺔ ﺻﻔﺮ ﻋﻨﺪ ﺃﺣﺪ ﻣﺴﺘﻮﻳﺎﺕ ﺍﻟﻌﻨﺼﺮ ﺍﻹﻧﺸﺎﺋﻲ ﺍﶈﻤﻞ ﻭﻳﺴﻤﻰ ﳏـﻮﺭ ﺍﻟﺘﻌـﺎﺩﻝ‬ ‫ﻟﻠﻌﻨﺼﺮ‪ ،‬ﻭﺗﻜﻮﻥ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﻨﺎﺷﺌﺔ ﻋﻦ ﺍﻟﻌﺰﻭﻡ ﻣﺼﺤﻮﺑﺔ ﺑﺈﺟﻬﺎﺩﺍﺕ ﻗﺺ ﺗﺆﺛﺮ ﻋﻠﻰ ﻗﻄﺎﻉ ﺍﻟﻌﻨـﺼﺮ‬ ‫ﺍﳌﺴﺘﺨﺪﻡ‪ .‬ﻭﲢﺪﺙ ﺣﺎﻟﺔ ﺍﻻﳓﻨﺎﺀ ﺇﺫﺍ ﺗﻌﺮﺿﺖ ﻛﻤﺮﺓ ﺇﱃ ﺃﲪﺎﻝ ﺭﺃﺳﻴﺔ ﺗﻌﻤﻞ ﰱ ﻣﺴﺘﻮﻯ ﺭﺃﺳﻲ ﻣﻊ ﳏﻮﺭ‬ ‫ﺍﻟﻜﻤﺮﺓ ﺃﻭ ﺇﱃ ﺃﲪﺎﻝ ﻻ ﳏﻮﺭﻳﺔ ﺗﻌﻤﻞ ﰱ ﺍﳌﺴﺘﻮﻯ ﺍﳌﺎﺭ ﲟﺤﻮﺭ ﺍﻟﻜﻤﺮﺓ ﺃﻭ ﺇﱃ ﻋﺰﻭﻡ ﺃﳓﻨـﺎﺀ ﺗﻌﻤـﻞ ﰱ‬ ‫ﻣﺴﺘﻮﻯ ﳏﻮﺭ ﺍﻟﻜﻤﺮﺓ ﻛﻤﺎ ﻳﺘﻀﺢ ﺫﻟﻚ ﰱ ﺷﻜﻞ )‪.(١-٤‬‬ ‫‪P‬‬

‫‪P‬‬

‫»‪ñŠà×@óÜÇ@ïc‰@Ý‬‬

‫‪P‬‬

‫‪P‬‬

‫»‪ðŒ×Šß@ü@ïÔÏc@Ý‬‬

‫‪M‬‬

‫‪M‬‬

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‫‘‪@ @Nõbä−übi@ÝîàznÛa@püby@HQMTI@ÝØ‬‬

‫‪٧٧‬‬

‫‪õbä−a@âëŒÇ‬‬


‫@@‬ ‫‪P2‬‬ ‫‪X‬‬

‫‪P2‬‬

‫‪P1‬‬

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‫‪M‬‬

‫‪P1‬‬

‫‪X‬‬

‫‪Q‬‬

‫‪N‬‬ ‫‪X‬‬

‫‪X‬‬

‫‪ð…ìàÇ@ÁÌ™@…bèug‬‬

‫‪X‬‬

‫‪—Ó@…bèug‬‬

‫‪õbä−a@…bèug‬‬

‫‘‪@ @PñŠà×@åß@ÉĐÔß@óÜÇ@ñ…ìuì½a@pa…bèu⁄a@HRMTI@ÝØ‬‬

‫ﻭﻗﺪ ﺗﺘﻌﺮﺽ ﺍﳌﻨﺸﺂﺕ ﺍﳍﻨﺪﺳﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ ﻭﺍﳌﺎﻛﻴﻨﺎﺕ ﺃﺛﻨﺎﺀ ﺗﺸﻐﻴﻠﻬﺎ ﺇﱃ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻻﳓﻨﺎﺀ ﺍﻟﱴ ﻗﺪ ﺗﻜﻮﻥ‬ ‫ﻣﺼﺤﻮﺑﺔ ﺑﺈﺟﻬﺎﺩ ﺷﺪ ﻣﺒﺎﺷﺮ ﺃﻭ ﺿﻐﻂ ﻣﺒﺎﺷﺮ ﺃﻭ ﺇﺟﻬﺎﺩﺍﺕ ﻗﺺ ﺃﻭ ﺇﺟﻬﺎﺩﺍﺕ ﺇﻟﺘﻮﺍﺀ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿـﺢ‬ ‫ﺑﺎﻟﺸﻜﻞ )‪ .(٢-٤‬ﻭﻳﻨﺘﺞ ﻋﻦ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﳌﺬﻛﻮﺭﺓ ﺍﻟﺴﺎﺑﻘﺔ ﻭﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﻜﻤـﺮﺓ‬ ‫ﺍﶈﻤﻠﺔ ﺍﻧﻔﻌﺎﻻﺕ ﺇﻧﻀﻐﺎﻁ ﻭﺇﻧﺰﻻﻕ ﻭﺇﻧﺜﻨﺎﺀ ﳍﺬﺍ ﺍﳌﻘﻄﻊ ﻛﻤﺎ ﻫﻮ ﻣﺒﲔ ﺑﺎﻟﺸﻜﻞ )‪ (٣-٤‬ﻭﺫﻟﻚ ﻧﺘﻴﺠـﺔ‬ ‫ﻹﺟﻬﺎﺩ ﺍﻟﻀﻐﻂ ﺍﳌﺒﺎﺷﺮ ﻭﺍﻟﻘﺺ ﻭﺍﻻﳓﻨﺎﺀ ﻋﻠﻰ ﺍﻟﺘﻮﺍﱃ‪.‬‬ ‫‪M‬‬ ‫‪N‬‬

‫‪N‬‬

‫‪@ @òí…ìàÈÛa@ôìÔÛa@qdm‬‬ ‫‪HÂbÌšãgI‬‬

‫‪M‬‬

‫‪Q‬‬ ‫‪Q‬‬

‫‪@ @—ÔÛa@ôìÓ@qdm‬‬ ‫@@‬ ‫‪HÖüŒãgI‬‬

‫@@‬

‫‪@ @õbä−üa@âëŒÇ@qdm‬‬ ‫‪HõbärãgI‬‬

‫‘‪@ @PñŠàØÛa@ÉĐÔß@óÜÇ@ñ…ìuì½a@pübÈÐãüa@HSMTI@ÝØ‬‬

‫ﺇﻥ ﺍﻷﺟﺰﺍﺀ ﻭﺍﻟﻌﻨﺎﺻﺮ ﺍﳌﻌﺮﺿﺔ ﺇﱃ ﺍﳓﻨﺎﺀ ﰱ ﺍﳌﻨﺸﺂﺕ ﺍﳌﺨﺘﻠﻔﺔ ﻭﺍﳌﺎﻛﻴﻨﺎﺕ ‪‬ﺗﺼ ‪‬ﻤﻢ ﻃﺒﻘـﹰﺎ ﻟﻠﻤﻌـﺎﺩﻻﺕ‬ ‫ﺍﳍﻨﺪﺳﻴﺔ ﺍﳋﺎﺻﺔ ﺑﺈﺟﻬﺎﺩ ﺍﻻﳓﻨﺎﺀ ﻭﻋﻼﻗﺘﻬﺎ ﺑﻘﻴﻤﺔ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻭﺃﺑﻌﺎﺩ ﺍﳌﻘﻄﻊ ﻭﻧﻮﻉ ﺍﳌﺎﺩﺓ ﺍﳌﺴﺘﺨﺪﻣﺔ ﰱ‬ ‫ﺍﻟﺘﺼﻤﻴﻢ ﻭﻋﻠﻰ ﺫﻟﻚ ﻓﺈﻧﻪ ﻳﻠﺰﻡ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﻋﻠﻰ ﺍﳌﺎﺩﺓ ﻗﺒﻞ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﰱ ﺍﳌﻨﺸﺄ ﺃﻭ ﺍﳌﺎﻛﻴﻨـﺔ‬ ‫ﻻﺳﻴﻤﺎ ﻭﺃﻥ ﻣﻌﺎﺩﻻﺕ ﺍﻻﳓﻨﺎﺀ ﺍﻟﺘﺼﻤﻴﻤﻴﺔ ﻻ ﲤﺜﻞ ﲤﺎﻣﹰﺎ ﺍﳊﺎﻟﺔ ﺍﻟﻔﻌﻠﻴﺔ ﺑﻞ ﲢﻮﻱ ﺷﻴﺌﺎ ﻣـﻦ ﺍﻟﺘﻘﺮﻳـﺐ‬ ‫‪٧٨‬‬


‫ﻧﺘﻴﺠﺔ ﻹﳘﺎﳍﺎ ﺑﻌﺾ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﺼﻐﲑﺓ ﺍﻟﻨﺎﲡﺔ ﻷﺳﺒﺎﺏ ﳐﺘﻠﻔﺔ ﻣﺜﻞ ﺗﻐﲑ ﺍﳌﻘﻄﻊ ﻣﻦ ﻣﻜـﺎﻥ ﻵﺧـﺮ‬ ‫ﻛﺬﻟﻚ ﻋﺪﻡ ﺇﻧﺘﻈﺎﻡ ﺍﳌﺎﺩﺓ ﻧﺘﻴﺠﺔ ﺍﺧﺘﻼﻑ ﻇﺮﻭﻑ ﺍﻟﺘﺤﻤﻴﻞ ﺍﻟﻨﻈﺮﻳﺔ ﻋﻦ ﻭﺍﻗﻊ ﺍﻟﺘﺤﻤﻴﻞ ﺃﺛﻨﺎﺀ ﺍﻟﺘـﺸﻐﻴﻞ‬ ‫ﺑﺎﻹﺿﺎﻓﺔ ﺇﱃ ﺃﻥ ﺍﻟﻔﺮﻭﺽ ﺍﻟﱴ ‪‬ﺑﻨﻴﺖ ﻋﻠﻴﻬﺎ ﻣﻌﺎﺩﻻﺕ ﺍﻻﳓﻨﺎﺀ ﺍﻟﺘﺼﻤﻴﻤﻴﺔ ﻻ ﳝﻜﻦ ﺍﻋﺘﺒﺎﺭﻫﺎ ﻛﺎﻣﻠﺔ ﺍﻟﺪﻗﺔ‬ ‫ﳉﻤﻴﻊ ﺍﳌﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ﻭﻏﲑ ﺍﳌﻌﺪﻧﻴﺔ ﺫﺍﺕ ﺍﳋﻮﺍﺹ ﺍﳌﺨﺘﻠﻔﺔ ﻭﺍﻟﺘﺮﻛﻴﺒﺎﺕ ﺍﳉﺰﻳﺌﻴﺔ ﺫﺍﺕ ﺍﻟﺘﻨﻮﻉ ﺍﻟﻜﺒﲑ ﰱ‬ ‫ﺍﻟﺸﻜﻞ ﻭﺍﻟﺘﻜﻮﻳﻦ‪ .‬ﻭﺇﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﻳﻌﻄﻲ ﻧﺘﺎﺋﺞ ﺗﻌﱪ ﻋﻦ ﻣﺪﻯ ﻣﻘﺎﻭﻣﺔ ﺍﳉﺴﻢ ﺍﳌﺨﺘﱪ ﻷﲪﺎﻝ ﺍﻻﳓﻨﺎﺀ‪،‬‬ ‫ﻷﻥ ﺍﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﳝﺜﻞ ﺍﺧﺘﺒﺎﺭﹰﺍ ﲢﺖ ﻇﺮﻭﻑ ﻭﺍﻗﻌﻴﺔ ﺑﺎﻟﻨـﺴﺒﺔ ﻟﻠﻤـﺎﺩﺓ ﻭﺍﻟﺘﺤﻤﻴـﻞ ﻭﺍﻹﺟﻬـﺎﺩﺍﺕ‬ ‫ﻭﺍﻻﻧﻔﻌﺎﻻﺕ ﺍﳌﺼﺎﺣﺒﺔ ﳍﺎ‪ .‬ﻭﻣﻦ ﻫﺬﺍ ﺍﻻﺧﺘﺒﺎﺭ ﻳﺴﻬﻞ ﺗﻌﻴﲔ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻠﻤﻮﺍﺩ ﻣﺜﻞ ﻣﻘﺎﻭﻣـﺔ‬ ‫ﺍﻻﳓﻨﺎﺀ ﻭﺍﻟﺼﻼﺑﺔ ﻭﺍﻟﺮﺟﻮﻋﻴﺔ ﻭﺍﳌﺘﺎﻧﺔ ﰱ ﺍﻻﳓﻨﺎﺀ ﻋﻼﻭﺓ ﻋﻠﻰ ﺑﻴﺎﻥ ﻣﺪﻯ ﺍﻹﺗﺰﺍﻥ ﺍﻹﻧﺸﺎﺋﻲ ﻟﻠﻜﻤـﺮﺍﺕ‬ ‫ﺫﺍﺕ ﺍﻟﻘﻄﺎﻋﺎﺕ ﻭﺍﻷﺣﺠﺎﻡ ﺍﳌﺨﺘﻠﻔﺔ‪ .‬ﻏﺎﻟﺒﺎ ﻓﺈﻥ ﺍﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﳛﺘﺎﺝ ﺇﱃ ﺃﲪﺎﻝ ﺻﻐﲑﺓ ﻹﲤﺎﻣﻪ ﻟـﺬﻟﻚ‬ ‫ﻓﺈﻥ ﻣﺎﻛﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﻟﻺﳓﻨﺎﺀ ﺑﺴﻴﻄﺔ ﻭﻏﲑ ﻏﺎﻟﻴﺔ ﺍﻟﺴﻌﺮ ﻭﻫﺬﻩ ﻣﻦ ﺃﻫﻢ ﳑﻴﺰﺍﺕ ﻫﺬﺍ ﺍﻻﺧﺘﺒﺎﺭ‪ ،‬ﻛﻤﺎ ﺃﻥ‬ ‫ﻫﺬﺍ ﺍﻻﺧﺘﺒﺎﺭ ﺃﻳﻀﺎ ﻳﻌﱪ ﺑﺪﻗﺔ ﻋﻦ ﺧﺎﺻﻴﱵ ﺍﻟﺼﻼﺑﺔ ﻭﺍﻟﺮﺟﻮﻋﻴﺔ ﺃﻛﺜﺮ ﻣﻦ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻭﺫﻟـﻚ ﻋـﻦ‬ ‫ﻃﺮﻳﻖ ﺗﻌﻴﲔ ﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ )ﺍﻟﺘﺸﻜﻞ ﰱ ﺍﻻﳓﻨﺎﺀ( ﻟﻠﻜﻤﺮﺓ ﺍﳌﺨﺘﱪﺓ ﺑﺴﻬﻮﻟﺔ ﻭﺩﻗﺔ ﺧـﺼﻮﺻﺎ ﻟﻠﻤـﻮﺍﺩ‬ ‫ﺍﻟﻘﺼﻔﺔ ﻣﺜﻞ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ ﺣﻴﺚ ﻳﻜﻮﻥ ﺍﻟﺘﺸﻜﻞ ﺍﻟﺬﻯ ﻳﺴﺘﺨﺪﻡ ﻟﺘﻌﻴﲔ ﺧﺎﺻﱴ ﺍﻟﺼﻼﺑﺔ ﻭﺍﻟﺮﺟﻮﻋﻴﺔ ﰱ‬ ‫ﺍﺧﺘﺒﺎﺭ ‪ †’Ûa‬ﺻﻐﲑﹰﺍ ﺟﺪﹰﺍ ﻭﻣﻦ ﺍﻟﺼﻌﺐ ﲢﺪﻳﺪﻩ ﺑﺪﻗﺔ ﰱ ﺍﻟﻮﻗﺖ ﺍﻟﺬﻱ ﻳﻜﻮﻥ ﻓﻴﻪ ﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ ﺫﺍ ﻗﻴﻤـﺔ‬ ‫ﻛﺒﲑﺓ ﻣﺮﺍﺕ ﻋﺪﻳﺪﺓ ﻣﻦ ﻗﻴﻤﺔ ﺍﻟﺘﺸﻜﻞ ﺍﶈﺪﺩ ﻣﻦ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ‪ .‬ﻭﻳﻌﺘﱪ ﺇﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﺍﺧﺘﺒـﺎﺭﹰﺍ ﻫﺎﻣـﹰﺎ‬ ‫ﻭﺿﺮﻭﺭﻳﹰﺎ ﻛﺎﺧﺘﺒﺎﺭ ﻗﺒﻮﻝ ﻟﻠﻤﻮﺍﺩ ﻛﻤﺎ ﻳﻌﺘﱪ ﺃﺳﺎﺳﹰﺎ ﺿﻤﻦ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﻼﺯﻣـﺔ ﺍﻟـﱴ ﺗـﻨﺺ ﻋﻠﻴﻬـﺎ‬ ‫ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻟﺘﺤﺪﻳﺪ ﺻﻼﺣﻴﺔ ﺃﻭ ﺭﻓﺾ ﺍﳌﻮﺍﺩ ﺍﳌﺴﺘﺨﺪﻣﺔ ﰱ ﺍﻷﻋﻤﺎﻝ ﺍﳍﻨﺪﺳﻴﺔ‪.‬‬ ‫‪ & '() 2-4‬ء ‪!"# "$ %‬‬

‫ﺗﻌﻴﲔ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻻﳓﻨﺎﺀ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﻳﺮﺗﻜﺰ ﻋﻠﻰ ﺍﻻﻓﺘﺮﺍﺿﺎﺕ ﺍﻵﺗﻴﺔ‪:‬‬ ‫‪-١‬‬

‫ﻣﻘﻄﻊ ﺍﻟﻜﻤﺮﺓ ﺍ‪‬ﻬﺪﺓ ﺑﺘﺄﺛﲑ ﻋﺰﻡ ﺍﻻﳓﻨﺎﺀ ‪.òãbvnß@ñ…bß@åß@æìØní‬‬

‫‪-٢‬‬

‫ﲣﻀﻊ ﻣﺎﺩﺓ ﺍﻟﻜﻤﺮﺓ ﺃﺛﻨﺎﺀ ﲢﻤﻴﻠﻬﺎ ﻟﻘﺎﻧﻮﻥ ﻫﻮﻙ ﺃﻯ ﺃ‪‬ﺎ ﳎﻬﺪﺓ ﰱ ‪ ò@ ;ãëŠ½a@…ë†y‬ﻭﻳﺘﺒـﻊ ﺫﻟـﻚ‬ ‫ﺍﻟﺘﻨﺎﺳﺐ ﺍﳋﻄﻲ ﺑﲔ ﺍﻻﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ‪.‬‬ ‫ﻣﻘﻄﻊ ﺍﻟﻜﻤﺮﺓ@‪@oibq‬ﰱ ﲨﻴﻊ ﺃﺟﺰﺍﺋﻬﺎ ﻭﻋﻠﻰ ﻛﺎﻣﻞ ﻃﻮﳍﺎ‪.‬‬ ‫ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﳌﺎﺩﺓ ﺍﻟﻜﻤﺮﺓ ﰱ ﺍﻟﺸﺪ ﻳﺴﺎﻭﻱ ﻣﻌﺎﻳﺮ ﻣﺮﻭﻧﺘﻬﺎ ﰱ ﺍﻟﻀﻐﻂ‪.‬‬ ‫ﺍﻟﻘﻮﻯ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﻟﻜﻤﺮﺓ ﻭﺭﺩﻭﺩ ﺍﻷﻓﻌﺎﻝ ﺍﻟﻨﺎﲡﺔ ﺗﻘﻊ ﲨﻴﻌﻬﺎ ‪ †@ ;ya@ë@ôìn;ß@óÏ‬ﻫﻮ ﻣـﺴﺘﻮﻯ‬ ‫ﳏﻮﺭ ﺍﻟﻜﻤﺮﺓ‪.‬‬ ‫ﻣﺴﺘﻮﻯ ﺃﻯ ﻣﻘﻄﻊ ﰱ ﺍﻟﻜﻤﺮﺓ ‪ bíìnß@ìç@bà×@ÝÄí‬ﺑﻌﺪ ﺗﺄﺛﲑ ﻋﺰﻡ ﺍﻻﳓﻨﺎﺀ ﻋﻠﻴﻪ‪.‬‬

‫‪-٣‬‬ ‫‪-٤‬‬ ‫‪-٥‬‬ ‫‪-٦‬‬

‫‪٧٩‬‬


‫‪P‬‬

‫‪X‬‬

‫‪X‬‬

‫‪x-x‬‬

‫‪εc‬‬

‫‪σc‬‬ ‫‪σ‬‬

‫‪yc‬‬

‫‪y‬‬

‫‪ε‬‬

‫‪y‬‬

‫)‪N.A (Neutral axis‬‬

‫ﳏﻮﺭ ﺍﻟﺘﻌﺎﺩﻝ‬

‫‪yt‬‬

‫‪σt‬‬ ‫ﺗﻮﺯﻳﻊ ﺍﻹﺟﻬﺎﺩ‬

‫‪εt‬‬ ‫ﺗﻮﺯﻳﻊ ﺍﻹﻧﻔﻌﺎﻝ‬

‫‪dy‬‬

‫‪M‬‬

‫ﻣﻘﻄﻊ ﻣﺴﺘﻌﺮﺽ ﰱ ﺍﻟﻜﻤﺮﺓ ‪X-X‬‬

‫‘‪@ @Nõbä−a@âŒÈi@òÜàª@ñŠàØÛ@āŠÈnß@ÉĐÔß@óÜÇ@pübÈÐãüaë@pa…bèuüa@Éí‹ìm@HTMTI@ÝØ‬‬

‫ﻭﺇﺫﺍ ﺍﻋﺘﱪﺕ ﺍﻟﻜﻤﺮﺓ ﺍﳌﺒﻴﻨﺔ ﺑﺎﻟﺸﻜﻞ )‪ (٤-٤‬ﺗﻮﰱ ﺍﻻﺷﺘﺮﺍﻃﺎﺕ ﺳﺎﻟﻔﺔ ﺍﻟـﺬﻛﺮ ﻓـﻴﻤﻜﻦ ﺣـﺴﺎﺏ‬ ‫ﺇﺟﻬﺎﺩﺍﺕ ﺍﻻﳓﻨﺎﺀ ﻋﻨﺪ ﺃﻯ ﻣﻘﻄﻊ ﺑﺎﻟﻜﻤﺮﺓ ﲢﺖ ﺗﺄﺛﲑ ﻋﺰﻡ ﺍﻻﳓﻨﺎﺀ ﺍﻟﺬﻯ ﻳﺴﺒﺐ ﺩﻭﺭﺍﻧﹰﺎ ﺣـﻮﻝ ﺧـﻂ‬ ‫ﻳﺴﻤﻰ ﺧﻂ ﺍﻟﺘﻌﺎﺩﻝ )‪ (Neutral axis‬ﻧﺘﻴﺠﺔ ﺣﺪﻭﺙ ﺇﺟﻬﺎﺩﺍﺕ ﺿﻐﻂ ﰱ ﺃﺟﺰﺍﺀﻩ ﺍﻟﻌﻠﻮﻳﺔ ﻭﺇﺟﻬﺎﺩﺍﺕ‬ ‫ﺷﺪ ﰱ ﺃﺟﺰﺍﺀﻩ ﺍﻟﺴﻔﻠﻴﺔ ﻭﺗﻜﻮﻥ ﺍﻹﺟﻬﺎﺩﺍﺕ ﻋﻨﺪ ﺧﻂ ﺍﻟﺘﻌـﺎﺩﻝ ﺗـﺴﺎﻭﻯ ﺻـﻔﺮﹰﺍ‪ ،‬ﻭﻋﻠﻴـﻪ ﺗﻜـﻮﻥ‬ ‫ﺍﻹﺟﻬﺎﺩﺍﺕ ﻣﻮﺯﻋﺔ ﺗﻮﺯﻳﻌﺎ ﻣﺴﺘﻮﻳﺎ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﻭﺗﺘﻨﺎﺳﺐ ﻗﻴﻤﺘﻬﺎ ﻋﻨﺪ ﺃﻯ ﻧﻘﻄﺔ ﺣﺴﺐ ﺑﻌﺪ ﻫﺬﻩ ﺍﻟﻨﻘﻄﺔ‬ ‫ﻋﻦ ﺧﻂ ﺍﻟﺘﻌﺎﺩﻝ ﻛﻤﺎ ﻫﻮ ﻣﺒﲔ ﺑﺎﻟﺸﻜﻞ )‪ .(٤-٤‬ﻭﻧﻈﺮﹰﺍ ﻷﻥ ﺍﻟﺘﺤﻤﻴﻞ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﻳﺘﻨﺎﺳﺐ ﻓﻴـﻪ‬ ‫ﺧﻄﻴﹰﺎ ﺍﻹﺟﻬﺎﺩ ﻭﺍﻻﻧﻔﻌﺎﻝ ﺍﳌﺼﺎﺣﺐ ﻟﻪ ﻓﺘﻜﻮﻥ ﻗﻴﻤﺔ ﺍﻹﺟﻬﺎﺩ ﻋﻨﺪ ﺃﻯ ﻧﻘﻄﺔ ﻣﺘﻨﺎﺳﺒﺔ ﻣﻊ ﺑﻌﺪ ﻫﺬﻩ ﺍﻟﻨﻘﻄﺔ‬ ‫ﻋﻦ ﺧﻂ ﺍﻟﺘﻌﺎﺩﻝ ﻭﳝﻜﻦ ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﺍﻟﻨﺘﺎﺋﺞ ﺍﻵﺗﻴﺔ ﻷﻱ ﻣﻘﻄﻊ ﻟﻠﻜﻤﺮﺓ ﲢﺖ ﺗﺄﺛﲑ ﻋﺰﻡ ﺍﻻﳓﻨﺎﺀ‪:‬‬ ‫‪= C = Constant‬‬

‫‪σt‬‬ ‫‪σ‬‬ ‫‪σc‬‬ ‫=‬ ‫=‬ ‫‪y‬‬ ‫‪yt‬‬ ‫‪yc‬‬ ‫‪1.‬‬ ‫‪1.0‬‬ ‫‪σ=y.C‬‬

‫ ﺣﻴﺚ ﺃﻥ ﻣﻘﻄﻊ ﺍﻟﻜﻤﺮﺓ ﻭﺍﻗﻊ ﲢﺖ ﺗﺄﺛﲑ ﻋﺰﻡ ﺍﻻﳓﻨﺎﺀ )‪ (M‬ﻓﻘﻂ ﻓﻴﻜﻮﻥ ﳎﻤﻮﻉ ﺍﻟﻘﻮﻯ ﰱ ﺇﲡـﺎﻩ‬‫ﳏﻮﺭ ﺍﻟﺴﻴﻨﺎﺕ ﰱ ﺍﳌﻘﻄﻊ ﺗﺴﺎﻭﻯ ﺻﻔﺮﹰﺍ‬ ‫‪Σ Fx = 0‬‬ ‫‪Σ Fx = Σ (σ .da) = ∫σ .da = ∫ y. C. da = C ∫ y. da = 0‬‬ ‫‪∫ y. da = 0‬‬

‫ﺃﻯ ﺃﻥ ﻋﺰﻡ ﺍﳌﺴﺎﺣﺔ ﺣﻮﻝ ﺧﻂ ﺍﻟﺘﻌﺎﺩﻝ ﻳﺴﺎﻭﻯ ﺻﻔﺮﺍﹰ‪ ،‬ﻭﻳﻌﲎ ﺫﻟﻚ ﺃﻥ ﺧﻂ ﺍﻟﺘﻌﺎﺩﻝ ﳝﺜﻞ ﳏـﻮﺭ ﳝـﺮ‬ ‫ﲟﺮﻛﺰ ﺍﻟﺜﻘﻞ ﻟﻠﻤﻘﻄﻊ‪.‬‬ ‫‪٨٠‬‬


‫ﻭﺣﻴﺚ ﺃﻥ ﺍﻟﻘﻄﺎﻉ ﰱ ﺣﺎﻟﺔ ﺇﺗﺰﺍﻥ ﻓﻴﻜﻮﻥ ﳎﻤﻮﻉ ﻋﺰﻭﻡ ﺍﻟﻘﻮﻯ ﺍﻟﺪﺍﺧﻠﻴﺔ )ﻋﺰﻭﻡ ﺍﺟﻬﺎﺩﺍﺕ ﺍﻻﳓﻨـﺎﺀ(‬ ‫ﺣﻮﻝ ﳏﻮﺭ ﺍﻟﺼﺎﺩﺍﺕ ﻳﺴﺎﻭﻯ ﻋﺰﻭﻡ ﺍﻟﻘﻮﻯ ﺍﳋﺎﺭﺟﻴﺔ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﺣﻮﻝ ﳏﻮﺭ ﺍﻟﺼﺎﺩﺍﺕ ﻳﺴﺎﻭﻯ‬ ‫ﺻﻔﺮﹰﺍ‪.‬‬ ‫‪∫ (y. C. da). x = 0‬‬

‫‪i.e.‬‬

‫‪(σ .da). x = 0‬‬

‫‪∫ x. y. da = 0‬‬

‫‪i.e.‬‬

‫‪C ∫ x. y. da = 0‬‬

‫ﺃﻯ ﺃﻥ ﻋﺰﻡ ﺍﳌﺴﺎﺣﺔ ﺣﻮﻝ ﳏﻮﺭ ﺍﻟﺴﻴﻨﺎﺕ ﻭﳏﻮﺭ ﺍﻟﺼﺎﺩﺍﺕ ﻟﻠﻤﻘﻄﻊ ﻳﺴﺎﻭﻯ ﺻﻔﺮﺍﹰ‪ ،‬ﻭﻳﻌـﲎ ﻫـﺬﺍ ﺃﻥ‬ ‫ﳏﻮﺭ ﺍﻟﺴﻴﻨﺎﺕ ﻭﳏﻮﺭ ﺍﻟﺼﺎﺩﺍﺕ ﻟﻠﻤﻘﻄﻊ ﻋﺒﺎﺭﺓ ﻋﻦ ﳏﺎﻭﺭ ﻋﺰﻡ ﺍﻟﻘﺼﻮﺭ ﺍﻟﺬﺍﰐ ﺍﻟﺮﺋﻴﺴﻴﺔ ﻟﻠﻤﻘﻄﻊ ﻭﺍﻟﱴ‬ ‫ﲤﺮ ﲟﺮﻛﺰ ﺛﻘﻠﻪ‪ .‬ﻭﺣﻴﺚ ﺃﻥ ﺍﻟﻘﻄﺎﻉ ﰱ ﺣﺎﻟﺔ ﺇﺗﺰﺍﻥ ﻓﻴﻜﻮﻥ ﳎﻤﻮﻉ ﻋﺰﻭﻡ ﺍﻟﻘـﻮﻯ ﺍﻟﺪﺍﺧﻠﻴـﺔ )ﻋـﺰﻭﻡ‬ ‫ﺇﺟﻬﺎﺩﺍﺕ ﺍﻻﳓﻨﺎﺀ( ﺣﻮﻝ ﳏﻮﺭ ﺍﻟﺴﻴﻨﺎﺕ ﻳﺴﺎﻭﻱ ﻋﺰﻭﻡ ﺍﻟﻘﻮﻯ ﺍﳋﺎﺭﺟﻴﺔ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﺣﻮﻝ ﳏﻮﺭ‬ ‫ﺍﻟﺴﻴﻨﺎﺕ ﻳﺴﺎﻭﻯ )‪.(M‬‬ ‫‪i.e.‬‬

‫‪Σ(σ.da).y = M‬‬

‫‪∫ (σ. y. da) = M‬‬

‫‪i.e. C ∫ y2. da = M‬‬

‫‪∫C.y.y. da = M‬‬ ‫‪∫ y2. da = Ix‬‬

‫‪But:‬‬

‫ﺣﻴﺚ ‪ = Ix‬ﻋﺰﻡ ﺍﳌﺴﺎﺣﺔ ﺍﻟﺜﺎﱏ ﻟﻠﻤﻘﻄﻊ ﻭﻳﺴﻤﻰ ﺍﻟﻘﺼﻮﺭ ﺍﻟﺬﺍﰐ ﻟﻠﻤﻘﻄﻊ ﺣﻮﻝ ﳏﻮﺭ ﺍﻟﺴﻴﻨﺎﺕ‪٠‬‬ ‫‪C. Ix = M‬‬

‫‪σ‬‬ ‫‪. Ix = M‬‬ ‫‪y‬‬ ‫‪1.‬‬

‫‪Then:‬‬

‫‪M. y‬‬ ‫‪IX‬‬

‫ﺇﺟﻬﺎﺩ ﺍﻻﳓﻨﺎﺀ )‪= (σ‬‬

‫‪σ‬‬ ‫‪y‬‬

‫=‪C‬‬

‫‪But:‬‬

‫=‪σ‬‬

‫ﻋﺰﻡ ﺍﻷﳓﻨﺎﺀ )‪ × (M‬ﺑﻌﺪ ﺍﳉﺰﺀ ﻣﻦ ﺍﻟﻘﻄﻊ ﻋﻦ ﺧﻂ ﺍﻟﺘﻌﺎﺩﻝ )‪( y‬‬ ‫ﻋﺰﻡ ﺍﻟﻘﺼﻮﺭ ﺍﻟﺬﺍﺗﻰ ﻟﻠﻤﻘﻄﻊ ﺣﻮﻝ ﺍﶈﻮﺭ ﺍﻟﺬﻯ ﻳﺪﻭﺭ ﺣﻮﻟﻪ ) ‪(Ix‬‬

‫ﻭﺑﺬﻟﻚ ﺗﻜﻮﻥ ﺃﻛﱪ ﻗﻴﻤﺔ ﻻﺟﻬﺎﺩﺍﺕ ﺍﻟﻀﻐﻂ ﻋﻨﺪ ﻧﻘﻂ ﺍﳌﻘﻄﻊ ﺍﻟﻄﺮﻳﻘﺔ ﺍﻟﻌﻠﻴﺎ ﻭﻋﻠـﻰ ﻣـﺴﺎﻓﺔ ) ‪(yc‬‬ ‫ﻭﻛﺬﻟﻚ ﺃﻛﱪ ﻹﺟﻬﺎﺩﺍﺕ ﻟﻠﺸﺪ ﻋﻨﺪ ﻧﻘﻂ ﺍﳌﻘﻄﻊ ﺍﻟﻄﺮﻳﻘﺔ ﺍﻟﺴﻔﻠﻰ ﻭﻋﻠﻰ ﻣﺴﺎﻓﺔ )‪.(yt‬‬ ‫‪M.yt‬‬ ‫‪IX‬‬

‫= ‪t‬‬

‫‪M.yC‬‬

‫‪σ‬‬ ‫‪٨١‬‬

‫‪IX‬‬

‫= ‪C‬‬

‫‪σ‬‬


‫‪(Section Modulus) ÊbĐÔÛa@ŠíbÈß‬‬ ‫‪Ix‬‬ ‫ﻣﻌﺎﻳﺮ ﺍﻟﻘﻄﺎﻉ ﻟﻠﻀﻐﻂ =‬ ‫‪yc‬‬

‫= ‪Zc‬‬

‫‪Ix‬‬ ‫ﻣﻌﺎﻳﺮ ﺍﻟﻘﻄﺎﻉ ﻟﻠﺸﺪ =‬ ‫‪yt‬‬

‫= ‪Zt‬‬

‫ﻭﰱ ﺣﺎﻟﺔ ﺍﳌﻘﺎﻃﻊ ﺍﳌﺘﺎﻣﺜﻠﺔ ﺣﻮﻝ ﳏﻮﺭ ﺍﻟﺴﻴﻨﺎﺕ ﺣﻴﺚ ) ‪ ( yC = yt‬ﻓﺈﻥ‪:‬‬ ‫‪ZC = Zt = Z‬‬ ‫‪M=σ.Z‬‬

‫‪M‬‬ ‫‪Z‬‬

‫;‪and‬‬

‫= ‪σC = σt‬‬

‫ﻭﳍﺬﻩ ﺍﻟﻨﺘﺠﻴﺔ ﺃﳘﻴﺔ ﰱ ﺗﺼﻤﻴﻢ ﺍﳌﻨﺸﺂﺕ ﻭﺍﳌﺎﻛﻴﻨﺎﺕ ﺍﳌﻌﺮﺿﺔ ﻟﻌﺰﻭﻡ ﺇﳓﻨﺎﺀ ﻣﻌﻠﻮﻡ )‪ (M‬ﻋﻠـﻰ ﺍﳌﻘﻄـﻊ‬ ‫ﺍﳌﺨﺘﱪ ﲝﻴﺚ ﻻ ﻳﺘﻌﺪﻯ ﺃﻛﱪ ﺇﺟﻬﺎﺩ ﺇﳓﻨﺎﺀ ﲟﻘﻄﻊ ﺍﻟﻜﻤﺮﺓ ﻋﻦ ﺇﺟﻬﺎﺩ ﻣﻌﲔ )‪ (σ‬ﻭﺫﻟﻚ ﺑﺘﻌـﻴﲔ ﻗﻴﻤـﺔ‬ ‫‪٠Z = M/σ‬‬ ‫ﻣﻌﺎﻳﺮ ﺍﻟﻘﻄﺎﻉ )‪ (Z‬ﺣﻴﺚ ‪σ ٠٠٠٠٠٠٠٠‬‬ ‫‪Moment of Inertia ómaˆÛa@‰ì–ÔÛa@âŒÇ‬‬

‫ﻷﳘﻴﺔ ﻣﻌﺮﻓﺔ ﻗﻴﻤﺔ ﻋﺰﻡ ﺍﻟﻘﺼﻮﺭ ﺍﻟﺬﺍﰐ ﻟﻠﻘﻄﺎﻋﺎﺕ ﺍﳌﺨﺘﻠﻔﺔ ﰱ ﺗﻌﻴﲔ ﺇﺟﻬﺎﺩ ﺍﻻﳓﻨﺎﺀ ﻓﺴﻮﻑ ﻧﺬﻛﺮ ﻓﻴﻤﺎ‬ ‫ﻳﻠﻲ ﻗﻴﻤﺔ ﻋﺰﻡ ﺍﻟﻘﺼﻮﺭ ﺍﻟﺬﺍﰐ ﻟﺒﻌﺾ ﺍﻟﻘﻄﺎﻋﺎﺕ ﺍﻟﺸﺎﺋﻌﺔ ﺍﻻﺳﺘﺨﺪﺍﻡ ﰱ ﺍﻟﻜﻤﺮﺍﺕ‪:‬‬ ‫‪@ @@ÝîĐnß@ÊbĐÓ@J‬‬

‫‪y‬‬

‫‪x‬‬

‫‪h‬‬

‫‪x‬‬

‫‪bh3‬‬ ‫= ‪- IX‬‬ ‫‪12‬‬

‫‪hb3‬‬ ‫= ‪- IY‬‬ ‫‪12‬‬

‫‪b‬‬

‫‪ðŠöa…@ÊbĐÓ@J‬‬

‫‪y‬‬

‫‪x‬‬

‫‪x‬‬

‫‪D‬‬

‫‪πD‬‬ ‫‪64‬‬

‫‪2‬‬

‫= ‪- IX = IY‬‬

‫‪@sÜrß@ÊbĐÓ@J‬‬ ‫‪y‬‬

‫‪h‬‬

‫‪x‬‬

‫‪x‬‬ ‫‪b‬‬

‫‪٨٢‬‬

‫‪bh3‬‬ ‫= ‪- IX‬‬ ‫‪36‬‬


‫ﻭﳛﺴﺐ ﻋﺰﻡ ﺍﻟﻘﺼﻮﺭ ﺍﻟﺬﺍﰐ ﻟﻠﻘﻄﺎﻋﺎﺕ ﺍﳌﺮﻛﺒﺔ ﺑﺘﻘﺴﻴﻤﻬﺎ ﺇﱃ ﺃﺷﻜﺎﻝ ﻫﻨﺪﺳﻴﺔ ﻣﻌﺮﻭﻓﺔ ﻭﰱ ﻫﺬﻩ ﺍﳊﺎﻟﺔ‬ ‫ﺗﻜﻮﻥ ﻗﻴﻤﺔ ﻋﺰﻡ ﺍﻟﻘﺼﻮﺭ ﺍﻟﺬﺍﰐ ﻟﻠﻘﻄﺎﻉ ﻋﺒﺎﺭﺓ ﻋﻦ ﺣﺎﺻﻞ ﲨﻊ ﻣﺮﻛﺒﺘﲔ‪ :‬ﺍﳌﺮﻛﺒﺔ ﺍﻷﻭﱃ ﻫـﻲ ﻋـﺰﻡ‬ ‫ﺍﻟﻘﺼﻮﺭ ﺍﻟﺬﺍﰐ ﻟﻜﻞ ﻗﺴﻢ ﺣﻮﻝ ﳏﻮﺭﻩ ﺍﻟﺬﻱ ﳝﺮ ﲟﺮﻛﺰ ﺛﻘﻠﻪ‪ ٠‬ﺃﻣﺎ ﺍﳌﺮﻛﺒﺔ ﺍﻟﺜﺎﻧﻴﺔ ﻓﻬﻲ ﻋﺒﺎﺭﺓ ﻋﻦ ﺍﻟﻌﺰﻡ‬ ‫ﺍﻟﺜﺎﱐ ﻟﻠﻤﺴﺎﺣﺔ ﺣﻮﻝ ﺍﶈﻮﺭ ﺍﻟﺮﺋﻴﺴﻲ ﻟﻠﺸﻜﻞ ﻛﻠﻪ‪.‬‬ ‫‪IX= IX' + A.y2‬‬

‫‪ +,- . !/ 3-4‬ء‬

‫ﳝﻜﻦ ﺗﻘﺴﻴﻢ ﺍﻻﺧﺘﺒﺎﺭ ﺗﺒﻌﹰﺎ ﻟﻄﺒﻴﻌﺔ ﺍﺳﺘﺨﺪﺍﻣﺔ ﺇﱃ ﺍﻟﻨﻮﻋﲔ ﺍﻟﺮﺋﻴﺴﻴﲔ ﺍﻟﺘﺎﻟﲔ‪:‬‬

‫‬

‫ﺍﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﺍﻟﻜﻤﺮﻱ‬

‫‬

‫ﺍﺧﺘﺒﺎﺭ ﺍﻟﺜﲎ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ‬

‫‪@ @ðŠàØÛa@õbä−üa@‰bjna@QMS@MT‬‬ ‫@@‬ ‫ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﺍﻟﻜﻤﺮﻱ ﻳﺘﻢ ﲢﻤﻴﻞ ﺍﻟﻜﻤﺮﺍﺕ ﺍﳌﺨﺘﱪﺓ ﺑﺄﲪﺎﻝ ﺗﺴﺒﺐ ﻋﺰﻡ ﺍﳓﻨﺎﺀ ﺣﱴ ﺍﻟﻜﺴﺮ‪ ،‬ﺣﻴﺚ‬ ‫ﻳﺘﻢ ﲢﺪﻳﺪ ﺍﳊﻤﻞ ﻭﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ ﻋﻨﺪ ﺍﻟﻜﺴﺮ ﻟﺘﻌﻴﲔ ﻣﻘﺎﻭﻣﺔ ﺍﻻﳓﻨﺎﺀ ﻭﺻﻼﺑﺔ ﻣﺎﺩﺓ ﺍﻟﻜﻤـﺮﺓ ﻭﻛـﺬﻟﻚ‬ ‫ﳝﻜﻦ ﺗﻮﻗﻴﻊ ﻭﺭﺳﻢ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ ﻟﺘﻌﻴﲔ ﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﳌﺎﺩﺓ ﺍﻟﻜﻤـﺮﺓ ﺍﳌﺨﺘـﱪﺓ‪.‬‬ ‫ﻭﺗﻨﺺ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻋﻠﻰ ﺿﺮﻭﺭﺓ ﺇﺟﺮﺍﺀ ﻫﺬﺍ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﻟﺘﺤﺪﻳـﺪ ﺧﺎﺻـﻴﱴ‬ ‫ﻣﻘﺎﻭﻣﺔ ﺍﻻﳓﻨﺎﺀ ﻭ ﺍﻟﺼﻼﺑﺔ‪.‬‬

‫‪ -١‬‬ ‫ﳚﺐ ﺃﻥ ﻳﻜﻮﻥ ﻛﺴﺮ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻧﺎﺗﺞ ﻣﻦ ﺗﺄﺛﲑ ﺍﻻﳓﻨﺎﺀ ﻭﻟﻴﺲ ﻣﻦ ﻗﻮﻯ ﺍﻟﻘﺺ ﺍﻷﻓﻘﻴﺔ ﺃﻭ ﺍﻟﺮﺃﺳـﻴﺔ‬ ‫ﻛﺬﻟﻚ ﻟﻴﺲ ﻧﺘﻴﺠﺔ ﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﺸﺪ ﺍﻟﻘﻄﺮﻱ )‪ (Diagonal Stress‬ﺍﳊﺎﺩﺛﺔ ﻣﻦ ﺗﺄﺛﲑ ﺍﻟﻘﺺ‪ .‬ﻭﳝﻜﻦ‬ ‫ﺃﻥ ﻧﻌﺘﱪ ﺃﻥ ﺍﻟﻌﻴﻨﺔ ﻣﻨﺎﺳﺒﺔ ﻹﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﻭﺗﻮﰱ ﺍﻻﺷﺘﺮﺍﻃﺎﺕ ﺍﻟﺴﺎﻟﻔﺔ ﺍﻟﺬﻛﺮ ﺇﺫﺍ ﻛﺎﻥ ﲝﺮ ﺍﻟﻌﻴﻨﺔ )‪(L‬‬ ‫ﺗﺴﺎﻭﻯ ﻣﻦ ‪ ٦‬ﺇﱃ ‪ ١٢‬ﻣﺮﺓ ﻣﻦ ﺍﺭﺗﻔﺎﻉ ﺍﻟﻌﻴﻨﺔ )‪ (d‬ﺃﻯ ﺃﻥ‪:‬‬ ‫‪L = 6d to 12d‬‬ ‫ﻗﺪ ﺗﺴﺘﺨﺪﻡ ﻛﻤﺮﺍﺕ ﺫﺍﺕ ﺃﺷﻜﺎﻝ ﻣﺘﻌﺪﺩﺓ ﻛﻌﻴﻨﺎﺕ ﻻﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﺍﻟﻜﻤـﺮﻱ ﻭﺫﻟـﻚ ﰱ ﺃﻋﻤـﺎﻝ‬ ‫ﺍﻷﲝﺎﺙ ﻭﺍﻷﻋﻤﺎﻝ ﺍﳋﺎﺻﺔ‪ ،‬ﺃﻣﺎ ﰱ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﺘﺠﺎﺭﻳﺔ ﻓﺘﻜﻮﻥ ﻋﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﻋﺒﺎﺭﺓ ﻋﻦ ﻛﻤـﺮﺍﺕ‬ ‫ﺑﺄﺑﻌﺎﺩ ﻗﻴﺎﺳﻴﺔ ﺗﺘﻮﻗﻒ ﻗﻴﻤﺘﻬﺎ ﻋﻠﻰ ﻧﻮﻉ ﺍﳌﺎﺩﺓ ﻭﺷﻜﻞ ﺍﻟﻜﻤﺮﺓ ﻭﻃﺮﻳﻘﺔ ﺍﻟﺘﺤﻤﻴﻞ‪ .‬ﻭﳚﺮﻯ ﺍﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ‬ ‫ﺍﻟﻜﻤﺮﻱ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﻣﺜﻞ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ ﻭﺍﳋﺮﺳﺎﻧﺔ ﻭﺍﳋﺸﺐ ﻭﺍﻟﻄﻮﺏ ﻭﻏﲑﻫﺎ‪.‬‬ ‫‪٨٣‬‬


‫‪ -٢‬ء ‬ ‫ﺗﺴﺘﺨﺪﻡ ﻣﺎﻛﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﺍﻟﻌﺎﻣﺔ ﰱ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﺍﻟﻜﻤﺮﻱ ﻛﻤﺎ ﺗﺴﺘﺨﺪﻡ ﺃﻳﻀﺎ ﻣﺎﻛﻴﻨـﺎﺕ‬ ‫ﻣﺼﻤﻤﺔ ﺧﺼﻴﺼﺎ ﳍﺬﺍ ﺍﻟﻐﺮﺽ ﻭﻫﻮ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﺍﻟﻜﻤﺮﻱ ﻓﻘﻂ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿـﺢ ﺑﺎﻟـﺸﻜﻞ‬ ‫)‪ (٥-٤‬ﻭﻳﺸﻤﻞ ﺟﻬﺎﺯ ﺍﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﺍﻷﺟﺰﺍﺀ ﺍﻟﺮﺋﻴﺴﻴﺔ ﺍﻵﺗﻴﺔ‪:‬‬ ‫•‬

‫ﻗﻮﺍﻋﺪ ﺍﻻﺭﺗﻜﺎﺯ ﻟﻠﻜﻤﺮﺓ‬

‫•‬

‫ﺃﺟﺰﺍﺀ ﺍﻟﺘﺄﺛﲑ ﺑﺎﳊﻤﻞ ﻋﻠﻰ ﺍﻟﻜﻤﺮﺓ‬

‫•‬

‫ﻗﺮﺹ ﻣﺪﺭﺝ ﻟﺒﻴﺎﻥ ﻗﻴﻤﺔ ﺍﳊﻤﻞ‬

‫•‬

‫ﺃﺟﻬﺰﺓ ﻗﻴﺎﺱ ﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ ﺃﻭ ﺃﺟﻬﺰﺓ ﻣﻘﺎﻳﻴﺲ ﺍﻻﻧﻔﻌﺎﻝ‬

‫‘‪@ @õbä−üa@‰bjna@òäî×bß@HUMTI@ÝØ‬‬ ‫@@‬

‫‪@ @@‹bØm‰üa@†ÇaìÓ@J‬‬ ‫ﳚﺐ ﺃﻥ ﺗﻜﻮﻥ ﻗﻮﺍﻋﺪ ﺍﻻﺭﺗﻜﺎﺯ ﲝﻴﺚ ﺗﻜﻮﻥ ﻓﻴﻪ ﺍﻟﻜﻤﺮﺓ ﺍﳌﺨﺘﱪﺓ ﰱ ﺍﻻﳓﻨﺎﺀ ﺣـﺮﺓ ﺍﳊﺮﻛـﺔ ﺃﺛﻨـﺎﺀ‬ ‫ﺍﻟﺘﺤﻤﻴﻞ ﺣﱴ ﻻ ﳛﺪﺙ ﺃﻯ ﺗﺮﻛﻴﺰ ﻟﻺﺟﻬﺎﺩﺍﺕ ﻋﻨﺪﻫﺎ ﻭﻛﺬﻟﻚ ﺗﻮﺿﻊ ﲝﺎﻟﺔ ﲤﻜﻦ ﻣﻦ ﺍﳊﺮﻛﺔ ﺍﳉﺎﻧﺒﻴـﺔ‬ ‫ﺍﻟﻘﻠﻴﻠﺔ ﺣﱴ ﻻ ﺗﺘﻮﻟﺪ ﺃﻳﺔ ﺇﺟﻬﺎﺩﺍﺕ ﺇﻟﺘﻮﺍﺋﻴﺔ ﺑﺎﻟﻜﻤﺮﺓ‪ .‬ﻭﺗﻨﺺ ﻣﻌﻈﻢ ﻣﻮﺍﺻﻔﺎﺕ ﺍﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﺍﻟﻜﻤﺮﻱ‬ ‫ﻋﻠﻰ ﺃﻥ ﺗﻠﻚ ﺍﻟﻘﻮﺍﻋﺪ ﺗﻜﻮﻥ ﻛﺘﻞ ﻣﻌﺪﻧﻴﺔ ﺍﺳﻄﻮﺍﻧﻴﺔ ﻛﻤﺎ ﻳﺘﻀﺢ ﻣﻦ ﺍﻟﺸﻜﻞ )‪ ،(٦-٤‬ﻛﻤـﺎ ﻳﻔـﻀﻞ‬ ‫ﻭﺿﻊ ﻗﻄﻌﺔ ﻟﻮﺣﻴﺔ ﺻﻐﲑﺓ ﻣﻦ ﻣﺎﺩﺓ ﻣﺮﻧﺔ ﻛﺎﳌﻄﺎﻁ ﺃﻭ ﺍﳋﺸﺐ ﺍﻷﺑﻠﻜﺎﺝ ﺑﲔ ﻗﻮﺍﻋﺪ ﺍﻻﺭﺗﻜﺎﺯ ﻭﺍﻟﻜﻤﺮﺓ‬ ‫‪٨٤‬‬


‫ﺍﳌﺨﺘﱪﺓ ﻭﺧﺎﺻﺔ ﰱ ﺣﺎﻟﺔ ﺍﻟﻜﻤﺮﺍﺕ ﺍﳌﺼﻨﻮﻋﺔ ﻣﻦ ﺍﳌﻮﺍﺩ ﻏﲑ ﺍﳌﻌﺪﻧﻴﺔ ﻛﺎﳋﺮﺳـﺎﻧﺔ ﻭﺍﳋـﺸﺐ ﻭﺫﻟـﻚ‬ ‫ﻟﺘﻮﺯﻳﻊ ﺍﳊﻤﻞ ﺑﺸﻜﻞ ﳝﻨﻊ ﺗﺮﻛﺰ ﺍﻻﺟﻬﺎﺩﺍﺕ ﺑﺎﻟﻜﻤﺮﺓ ﻋﻨﺪ ﻧﻘﻂ ﺍﺭﺗﻜﺎﺯﻫﺎ‪ ،‬ﻭﳚﺐ ﺃﻳـﻀﺎ ﺃﻥ ﺗـﺴﻤﺢ‬ ‫ﺍﻟﺮﻛﺎﺋﺰ ﺑﻌﻤﻞ ﻣﺮﺗﻜﺰ ﻣﻔﺼﻠﻲ ﻣﺜﺒﺖ ﲜﺴﻢ ﺟﻬﺎﺯ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺍﻵﺧﺮ ﺣﺮ ﺍﳊﺮﻛﺔ ﻋﻠﻰ ﺟﺴﻢ ﺍﳉﻬﺎﺯ ﻛﻤﺎ‬ ‫ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪.(٦-٤‬‬ ‫‪Šqû½a@Ýà§a‬‬

‫‪Applied Load‬‬

‫‪@‰bjnüa@òäî×bß@÷c‰‬‬

‫»‪ńĐÔã@óÜÇ@Ê‹ìß@Ý‬‬ ‫‪Tow Point Loading‬‬ ‫‪Beam ñn‚½a@ñŠàØÛa‬‬

‫‪ò×Š§a@ñŠy@ñŒî×‰‬‬

‫‪õbä−üa@áè@îíbÔß‬‬

‫‪ò÷bu@ñŒî×‰‬‬

‫‪ò÷bu@‹bØm‰a@ñ†ÇbÓ‬‬

‫‘‪@ @ôŠàØÛa@õbä−üa@‰bjna@óÏ@‹bØm‰üa@†ÇaìÓ@HVMTI@ÝØ‬‬

‫‪@ @@ÝîàznÛa@ÁÔã@J‬‬ ‫ﻟﻨﻘﻂ ﺍﻟﺘﺤﻤﻴﻞ ﻧﻔﺲ ﺍﻟﺸﺮﻭﻁ ﺍﻟﱴ ﺳﺒﻖ ﺫﻛﺮﻫﺎ ﰱ ﻗﻮﺍﻋﺪ ﺍﻻﺭﺗﻜﺎﺯ ﻟﻨﻘﻞ ﺍﻷﲪﺎﻝ ﻣﻦ ﻣﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒـﺎﺭ‬ ‫ﺇﱃ ﺍﻟﻜﻤﺮﺓ ﺍﳌﺨﺘﱪﺓ ﲝﻴﺚ ﺗﻜﻮﻥ ﻣﻮﺯﻋﺔ ﺗﻮﺯﻳﻌﹰﺎ ﻣﻨﺘﻈﻤﹰﺎ ﲤﺎﻣﹰﺎ‪ .‬ﻭﺗﻮﺿﻊ ﻗﻄﻊ ﺍﻟﺘﺤﻤﻴﻞ ﲟﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒـﺎﺭ‬ ‫ﲝﻴﺚ ﺗﻨﻘﻞ ﺍﳊﻤﻞ ﺇﱃ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﰱ ﻧﻘﻄﺔ ﰱ ﻣﻨﺘﺼﻒ ﺍﻟﻜﻤﺮﺓ ﲝﻴﺚ ﻳﻨﺘﻘﻞ ﺍﳊﻤﻞ ﺇﱃ ﺍﻟﻜﻤـﺮﺓ ﰱ‬ ‫ﻧﻘﻄﺘﲔ ﺑﺒﺤﺮ ﺍﻟﻜﻤﺮﺓ ﻭﻫﻰ ﻧﻘﻄﱴ ﺍﻟﺜﻠﺚ ﺃﻭ ﺭﺑﻊ ﺍﻟﺒﺤﺮ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ .(٧-٤‬ﻭﻟﻠﺘﺤﻤﻴﻞ‬ ‫ﰱ ﻧﻘﻄﺘﲔ ﺃﳘﻴﺔ ﺧﺎﺻﺔ ﻭﻫﻰ ﺃﻧﻪ ﳝﻜﻦ ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﻣﻨﻄﻘﺔ ﺑﺎﻟﻜﻤﺮﺓ ﺗﻜﻮﻥ ﲢﺖ ﺗﺄﺛﲑ ﻋـﺰﻡ ﺍﻻﳓﻨـﺎﺀ‬ ‫ﺍﳋﺎﻟﺺ ﺑﺪﻭﻥ ﻗﻮﻯ ﻗﺺ ﻭﺫﻟﻚ ﳛﺪﺙ ﺑﲔ ﺍﳊﻤﻠﲔ ﺍﳌﺆﺛﺮﻳﻦ ﻭﻳﻔﻀﻞ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺘﺤﻤﻴﻞ ﰱ ﺑﻌﺾ‬ ‫ﺍﳌﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﻭﺑﺎﻷﺧﺺ ﺍﳋﺮﺳﺎﻧﺔ‪ .‬ﺃﻣﺎ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﻤﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ﺍﻟﻘﺼﻔﺔ ﻛﺎﳊﺪﻳﺪ ﺍﻟﺰﻫـﺮ ﻳﻔـﻀﻞ ﺃﻥ‬ ‫ﻳﻜﻮﻥ ﺍﻟﺘﺤﻤﻴﻞ ﰱ ﻧﻘﻄﺔ ﰱ ﻣﻨﺘﺼﻒ ﺍﻟﻜﻤﺮﺓ ﻟﺴﻬﻮﻟﺘﻪ ﺭﻏﻢ ﺗﻌﺮﺽ ﺍﻟﻜﻤﺮﺓ ﺇﱃ ﻋﺰﻡ ﺇﳓﻨﺎﺀ ﻭﻗﻮﺓ ﻗـﺺ‬ ‫ﺣﻴﺚ ﺃﻥ ﻫﺬﻩ ﺍﳌﻮﺍﺩ ﳍﺎ ﻣﻘﺎﻭﻣﺔ ﺃﻛﱪ ﰱ ﺍﻟﻘﺺ ﻋﻨﻬﺎ ﰱ ﲢﻤﻴﻞ ﺍﻟﺸﺪ ﻭﻳﺴﺒﺐ ﲢﻤﻴﻞ ﺍﻟﻜﻤﺮﺓ ﻛـﺴﺮﻫﺎ‬ ‫ﺑﻘﻮﺓ ﺍﻟﺸﺪ ﺍﻟﻨﺎﲡﺔ ﻣﻦ ﻋﺰﻡ ﺍﻻﳓﻨﺎﺀ ﻭﻟﻴﺲ ﺑﻘﻮﺓ ﺍﻟﻘﺺ ﺍﻷﻣﺮ ﺍﻟﺬﻯ ﳚﻌﻞ ﺍﻻﺧﺘﺒﺎﺭ ﻫﻮ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻜﻤـﺮﺓ‬ ‫ﻟﻌﺰﻡ ﺍﻻﳓﻨﺎﺀ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺸﻜﻞ )‪.(٧-٤‬‬ ‫‪٨٥‬‬


‫‪P‬‬

‫‪P‬‬

‫‪L/2‬‬

‫‪P‬‬

‫‪L/2‬‬

‫‪L/3‬‬

‫‪L‬‬

‫‪L‬‬

‫ﲢﻤﻴﻞ ﰱ ﻧﻘﻄﺔ ﻭﺍﺣﺪﺓ‬

‫‪L/3‬‬

‫‪L/3‬‬

‫‪L/4‬‬

‫ﲢﻤﻴﻞ ﰱ ﻧﻘﻄﺘﲔ ﰱ ﺛﻠﺚ ﺍﻟﺒﺤﺮ‬

‫‪L/2‬‬

‫‪L/4‬‬

‫‪L‬‬

‫ﲢﻤﻴﻞ ﰱ ﻧﻘﻄﺘﲔ ﰱ ﺭﺑﻊ ﺍﻟﺒﺤﺮ‬

‫‘‪@ @ôŠàØÛa@õbä−üa@‰bjna@óÏ@ÝîàznÛa@ÁÔã@HWMTI@ÝØ‬‬

‫‪@ @ÞbÈÐãüaë@õbä−üa@áè@÷bîÓ@ñŒèuc@J‬‬ ‫ﻳﺮﺍﻋﻰ ﻋﻨﺪ ﻭﺿﻊ ﺃﺟﻬﺰﺓ ﻗﻴﺎﺱ ﻗﻴﻤﺔ ﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ ﻟﻠﻜﻤﺮﺓ ﺍﳌﺨﺘﱪﺓ ﺃﻥ ﲢﻘﻖ ﺍﳌﻄﻠﻮﺏ ﻣـﻦ ﺍﻹﺧﺘﺒـﺎﺭ‬ ‫ﻟﻠﻘﻴﺎﺱ ﰱ ﻧﻘﻄﺔ ﺃﻭ ﺃﻛﺜﺮ ﻣﻦ ﲝﺮ ﺍﻟﻜﻤﺮﺓ ﺣﺴﺐ ﻣﺘﻄﻠﺒﺎﺕ ﺍﻹﺧﺘﺒﺎﺭ‪ ،‬ﻛﻤﺎ ﻳﺮﺍﻋﻰ ﺃﻥ ﺗﺜﺒـﺖ ﺑﻄﺮﻳﻘـﺔ‬ ‫ﲢﺎﻓﻆ ﻋﻠﻴﻬﺎ ﻣﻦ ﺍﻟﻜﺴﺮ ﻋﻨﺪ ﺍ‪‬ﻴﺎﺭ ﺍﻟﻜﻤﺮﺓ ﺍﳌﺨﺘﱪﺓ ﻭﺿﻤﺎﻥ ﺩﻗﺔ ﺍﻟﻘﻴﺎﺱ‪.‬ﻛﻤﺎ ﺗﺴﺘﺨﺪﻡ ﺃﻳﻀﹰﺎ ﻣﻘـﺎﻳﻴﺲ‬ ‫ﺍﻹﻧﻔﻌﺎﻝ ﻟﻘﻴﺎﺱ ﺍﻟﺘﺸﻜﻞ ﺍﳊﺎﺩﺙ ﺑﺎﻟﻜﻤﺮﺓ ﺍﳌﺨﺘﱪﺓ ﺑﺎﺳﺘﻌﻤﺎﻝ ﺍﻷﺟﻬﺰﺓ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﺃﻭ ﺍﻟﻀﻮﺋﻴﺔ ﺃﻭ ﻗﻴﺎﺱ‬ ‫ﺍﻹﻧﻔﻌﺎﻝ ﻣﺒﺎﺷﺮﺓ ﻋﻨﺪ ﺇﺳﺘﻌﻤﺎﻝ ﺃﺟﻬﺰﺓ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻜﻬﺮﺑﻴﺔ ﻭﺫﻟﻚ ﺑﺘﺜﺒﻴﺘﻬﺎ ﺭﺃﺳﻴﹰﺎ ﻋﻠﻰ ﺍﻟﺴﻄﺢ ﺍﻟﻌﻠـﻮﻱ‬ ‫ﻭﺍﻟﺴﻔﻠﻲ ﻟﻠﻜﻤﺮﺓ ﻋﻨﺪ ﺃﻛﱪ ﺇﺟﻬﺎﺩ ﺷﺪ ﺃﻭ ﺿﻐﻂ ﻭﺃﺣﻴﺎﻧﺎ ﻳﺘﻢ ﺗﺜﺒﻴﺘﻬﺎ ﻋﻠﻰ ﺍﻟﺴﻄﺢ ﺍﳉـﺎﻧﱯ ﻟﻠﻜﻤـﺮﺓ‬ ‫ﻟﺒﻴﺎﻥ ﺍﻻﺟﻬﺎﺩﺍﺕ ﺍﳌﺨﺘﻠﻔﺔ ﻋﻨﺪ ﺍﻟﻨﻘﻂ ﺍﳌﺨﺘﻠﻔﺔ ﳌﻘﻄﻊ ﺍﻟﻜﻤﺮﺓ‪.‬‬

‫‪ -٣‬ء‬ ‫ﻣﻦ ﺃﻫﻢ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﰱ ﺍﻻﳓﻨﺎﺀ ﻣﺎ ﻳﻠﻲ‪:‬‬ ‫•‬

‫ﻣﻘﺎﻭﻣﺔ ﺍﻻﳓﻨﺎﺀ‬

‫ﻳﺘﻢ ﺗﻌﻴﲔ ﻣﻘﺎﻭﻣﺔ ﺍﻻﳓﻨﺎﺀ ﰱ ﺣﺪﻭﺩ ﺍﳌﺮﻭﻧﺔ ﲝﺴﺎﺏ ﺇﺟﻬﺎﺩ ﺍﻻﳓﻨﺎﺀ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻭﺫﻟـﻚ ﺑﺮﺳـﻢ‬ ‫ﺍﳌﻨﺤﲎ ﺍﻟﺒﻴﺎﱏ ﻟﻠﺤﻤﻞ ﻭﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ ﻣﻦ ﻭﺍﻗﻊ ﺍﻟﻘﺮﺍﺀﺍﺕ ﺍﳌﻌﻤﻠﻴﺔ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟـﺸﻜﻞ )‪(٨-٤‬‬ ‫ﻭﲢﺪﻳﺪ ﺍﳊﻤﻞ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﰒ ﺣﺴﺎﺏ ﺍﻹﺟﻬﺎﺩ ﻣﻦ ﺍﳌﻌﺎﺩﻟﺔ ﺍﻵﺗﻴﺔ‪:‬‬

‫‪M.Y‬‬ ‫‪I‬‬

‫‪٨٦‬‬

‫=‪σ‬‬


‫ﺃﻣﺎ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻟﻼﳓﻨﺎﺀ ﻭﺍﻟﱴ ﺗﺴﻤﻰ ﻣﻌﺎﻳﺮ ﺍﻟﻜﺴﺮ )‪ (Modulus of Rupture‬ﻓﺘﻌﲔ ﻟﻠﻤـﻮﺍﺩ‬ ‫ﺍﻟﻘﺼﻔﺔ ﻭﻫﻰ ﺍﻟﱴ ﳚﺮﻯ ﻋﻠﻴﻬﺎ ﺇﺧﺘﺒﺎﺭ ﺍﻻﳓﻨﺎﺀ ﺍﻟﻜﻤﺮﻱ ﻏﺎﻟﺒﺎ ﺑﺎﺳﺘﺨﺪﺍﻡ ﻧﻔﺲ ﺍﳌﻌﺎﺩﻟﺔ ﺍﻟﺴﺎﺑﻘﺔ‪ ،‬ﻭﻣﻊ ﺃﻥ‬ ‫ﻫﺬﻩ ﺍﳌﻌﺎﺩﻟﺔ ﻣﺴﺘﻨﺘﺠﺔ ﻋﻠﻰ ﺃﺳﺎﺱ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﻓﻘﻂ ﺇﻻ ﺃﻧﻪ ﳝﻜﻦ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﻣﻊ ﺍﻟﺘﻘﺮﻳـﺐ ﺍﻟﺒـﺴﻴﻂ‬ ‫ﻟﻠﻤﻌﺎﺩﻥ ﺍﻟﻘﺼﻔﺔ ﻧﻈﺮﹰﺍ ﻟﻌﺪﻡ ﺗﻐﲑ ﻣﻘﻄﻊ ﺍﻟﻜﻤﺮﺓ ﺗﻐﲑﹰﺍ ﻣﻠﺤﻮﻇﹰﺎ ﻋﻨﺪ ﺍﻟﻜﺴﺮ ﻋﻦ ﺍﳌﻘﻄﻊ ﺃﺛﻨﺎﺀ ﺍﻟﺘﺤﻤﻴـﻞ‬ ‫ﺍﻷﻭﱃ ﺍﳌﺮﻥ ‪ ،‬ﻭﲢﺴﺐ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻣﻦ ﲪﻞ ﺍﻟﻜﺴﺮ ﺃﻭ ﺍﳊﻤﻞ ﺍﻷﻗﺼﻰ ﰱ ﺍﻹﺧﺘﺒﺎﺭ‪.‬‬ ‫ﺍﳊﻤﻞ‬ ‫‪P‬‬

‫ﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ‬

‫∆‬


‫ﺃﻗﺼﻰ ﲪﻞ‬

‫ﲪﻞ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ‬ ‫‪L/2‬‬

‫‪L/2‬‬

‫‪L‬‬

‫∆ ﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ ‪Deflection‬‬

‫‘‪@ @ðŠàØÛa@õbä−üa@‰bjna@óÏ@òîØîãbØî½a@ãìä@´îÈm@HXMTI@ÝØ‬‬ ‫•‬

‫ﺍﻟﺼﻼﺑﺔ‬

‫ﺗﻘﺎﺱ ﺻﻼﺑﺔ ﳌﺎﺩﺓ ﺑﻘﻴﻤﺔ ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﳍﺬﻩ ﺍﳌﺎﺩﺓ ﺣﻴﺚ ﺃﻥ ﺍﻟﺼﻼﺑﺔ ﺗﺘﻨﺎﺳﺐ ﻃﺮﺩﻳﺎ ﻣﻊ ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧـﺔ‪،‬‬ ‫ﻭﻳﻌﲔ ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﻣﻦ ﺍﳌﻌﺎﺩﻻﺕ ﺍﻵﺗﻴﺔ‪:‬‬ ‫‪-‬‬

‫ﰱ ﺣﺎﻟﺔ ﺍﻟﺘﺤﻤﻴﻞ ﲝﻤﻞ ﻣﺮﻛﺰ ﰱ ﻣﻨﺘﺼﻒ ﺍﻟﻜﻤﺮﺓ‪:‬‬ ‫‪PL3‬‬

‫‪PL3‬‬

‫‪48∆I‬‬

‫‪-‬‬

‫=‪E‬‬

‫‪48EI‬‬

‫ﰱ ﺣﺎﻟﺔ ﺍﻟﺘﺤﻤﻴﻞ ﲝﻤﻠﲔ ﻣﺮﻛﺰﻳﻦ ﻋﻨﺪ ﺍﻟﺜﻠﺚ ﺍﻷﻭﺳﻂ ﻟﻠﻜﻤﺮﺓ‪:‬‬ ‫‪23PL3‬‬

‫‪23PL3‬‬ ‫‪1296∆I‬‬

‫‪-‬‬

‫= ‪∆max‬‬

‫=‪E‬‬

‫‪1296EI‬‬

‫= ‪∆max‬‬

‫ﰱ ﺣﺎﻟﺔ ﺍﻟﺘﺤﻤﻴﻞ ﲝﻤﻞ ﻣﻮﺯﻉ ﻋﻠﻰ ﻃﻮﻝ ﺍﻟﻜﻤﺮﺓ‪:‬‬ ‫‪5 WL4‬‬ ‫‪384∆I‬‬

‫‪5 WL4‬‬ ‫=‪E‬‬

‫‪384EI‬‬

‫‪٨٧‬‬

‫= ‪∆max‬‬


‫ﻛﺬﻟﻚ ﳝﻜﻦ ﺍﻟﺘﻌﺒﲑ ﻋﻦ ﺻﻼﺑﺔ ﺍﳌﺎﺩﺓ )ﻋﻼﻭﺓ ﻋﻠﻰ ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ( ﺑﻘﻴﻤﺔ ﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ ﺍﻷﻗـﺼﻰ ﻋﻨـﺪ‬ ‫ﺍﻟﻜﺴﺮ )‪ (∆max‬ﻭﺗﻘﺎﺭﻥ ﻫﺬﻩ ﺍﻟﻘﻴﻤﺔ ﺑﺎﳊﺪ ﺍﻷﺩﱏ ﺍﳌﺒﲔ ﺑﺎﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻋﻨـﺪ ﺇﺟـﺮﺍﺀ ﺍﺧﺘﺒـﺎﺭ‬ ‫ﺍﻻﳓﻨﺎﺀ ﺍﻟﻜﻤﺮﻱ ﻟﻘﺒﻮﻝ ﺃﻭ ﺭﻓﺾ ﺍﳌﻮﺍﺩ‪.‬‬ ‫•‬

‫ﺍﻟﺮﺟﻮﻋﻴﺔ‬

‫ﺍﻟﺮﺟﻮﻋﻴﺔ ﰱ ﺍﻻﳓﻨﺎﺀ ﻫﻰ ﻗﻴﻤﺔ ﺃﻛﱪ ﻃﺎﻗﺔ ﳝﻜﻦ ﻟﻠﻜﻤﺮﺓ ﺃﻥ ﲣﺘﺰ‪‬ﺎ ﻭﻫﻰ ﲢﺖ ﺗﺄﺛﲑ ﺍﳊﻤﻞ ﰱ ﺣـﺪﻭﺩ‬ ‫ﺍﳌﺮﻭﻧﺔ ﰒ ﺇﻋﺎﺩﺓ ﻫﺬﻩ ﺍﻟﻄﺎﻗﺔ ﻛﺎﻣﻠﺔ ﺑﻌﺪ ﺇﺯﺍﻟﺔ ﺍﻟﺘﺤﻤﻴﻞ‪ .‬ﺣﻴﺚ ﺗﻜﻮﻥ ﺍﻟﺮﺟﻮﻋﻴﺔ ﺗﺴﺎﻭﻯ ﻣﺴﺎﺣﺔ ﺍﳌﺜﻠﺚ‬ ‫ﺍﻟﻮﺍﻗﻊ ﲢﺖ ﺧﻂ ﺍﻟﺘﻨﺎﺳﺐ ﺑﲔ ﺍﳊﻤﻞ ﻭﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ‪ .‬ﻭﳝﻜﻦ ﺍﻟﺘﻌﺒﲑ ﻋﻦ ﺭﺟﻮﻋﻴﺔ ﺍﳌﻮﺍﺩ ﻭﻣﻘﺎﺭﻧﺘـﻬﺎ ﰱ‬ ‫ﺍﳌﻮﺍﺩ ﺍﳌﺨﺘﻠﻔﺔ ﲟﻌﺎﻳﺮ ﺍﻟﺮﺟﻮﻋﻴﺔ ﻭﻳﺴﺎﻭﻯ ﺍﻟﺮﺟﻮﻋﻴﺔ ﻣﻘﺴﻮﻣﺔ ﻋﻠﻰ ﺣﺠﻢ ﺍﻟﻜﻤﺮﺓ ﺍﶈﻤﻠﺔ‪.‬‬ ‫•‬

‫ﺍﳌﺘﺎﻧﺔ‬

‫ﲢﺪﺩ ﻗﻴﻤﺔ ﺍﳌﺘﺎﻧﺔ ﰱ ﺍﻻﳓﻨﺎﺀ ﺑﺎﻟﻄﺎﻗﺔ ﺍﻟﻘﺼﻮﻯ ﺍﻟﱴ ﳝﻜﻦ ﻟﻠﻜﻤﺮﺓ ﺍﳌﺨﺘﱪﺓ ﲢﻤﻠﻬﺎ ﺣﱴ ﺍﻟﻜﺴﺮ ﻭﲤﺜﻠـﻬﺎ‬ ‫ﺍﳌﺴﺎﺣﺔ ﺍﻟﻜﻠﻴﺔ ﲢﺖ ﻣﻨﺤﲎ ﺍﳊﻤﻞ ﻭﺳﻬﻢ ﺍﻻﳓﻨﺎﺀ‪ ،‬ﻭﳝﻜﻦ ﺍﻟﺘﻌﺒﲑ ﻋﻦ ﻣﻘﺎﻭﻣﺔ ﺍﳌﺎﺩﺓ ﻟﻠﺼﺪﻡ ﰱ ﲢﻤﻴـﻞ‬ ‫ﺍﻻﳓﻨﺎﺀ ﲝﺴﺎﺏ ﻣﻌﺎﻳﺮ ﺍﳌﺘﺎﻧﺔ ﻭﺍﻟﺬﻯ ﻳﺴﺎﻭﻯ ﺍﳌﺘﺎﻧﺔ ﻣﻘﺴﻮﻣﺔ ﻋﻠﻰ ﺣﺠﻢ ﺍﻟﻜﻤﺮﺓ ﺍﶈﻤﻠﺔ ﻓﻘﻂ‪.‬‬

‫‪ ! -٤‬ء "‬ ‫ﺷﻜﻞ ﺍﻻ‪‬ﻴﺎﺭ ﰱ ﺍﻟﻜﻤﺮﺍﺕ ﺍﳌﺨﺘﱪﺓ ﳜﺘﻠﻒ ﻃﺒﻘﺎ ﻟﻠﻌﻮﺍﻣﻞ ﺍﻵﺗﻴﺔ‪:‬‬ ‫‪-‬‬

‫ﻧﻮﻉ ﺍﳌﺎﺩﺓ‪.‬‬

‫‬‫‬‫‬‫‪-‬‬

‫ﻧﻮﻉ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﳌﺴﺒﺒﺔ ﻟﻺ‪‬ﻴﺎﺭ‪.‬‬ ‫ﺃﺑﻌﺎﺩ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ‪.‬‬ ‫ﺷﻜﻞ ﻭﺃﺑﻌﺎﺩ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ‪.‬‬ ‫ﺍﻟﻌﻼﻗﺔ ﺑﲔ ﺍﺭﺗﻔﺎﻉ ﺍﻟﻜﻤﺮﺓ ﻭﻃﻮﻝ ﲝﺮﻫﺎ‪.‬‬

‫ﻳﻜﻮﻥ ﺍﻻ‪‬ﻴﺎﺭ ﻏﺎﻟﺒﺎ ﰱ ﺍﳌﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﺑﺎﻟﻜﺴﺮ ﰱ ﺍﳌﻘﻄﻊ ﺍﻷﻛﺜﺮ ﺇﺟﻬﺎﺩﹰﺍ ﻋﻨﺪ ﺟﺰﻳﺌﺎﺗﻪ ﺍﻟﻄﺮﻓﻴﺔ ﺍ‪‬ﻬـﺪﺓ‬ ‫ﺑﺎﻟﺸﺪ ﺣﻴﺚ ﺃﻥ ﳓﻤﻞ ﺍﳌﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﻟﻠﺸﺪ ﺿﻌﻴﻒ ﺑﺎﻟﻨﺴﺒﺔ ﻟﺘﺤﻤﻠﻬﺎ ﰱ ﺍﻟﻀﻐﻂ‪ .‬ﻓﻤﺜﻼ ﻳﺘﺤﻤﻞ ﺍﳊﺪﻳﺪ‬ ‫ﺍﻟﺰﻫﺮ ﰱ ﺍﻟﺸﺪ ﺣﻮﺍﱃ ‪ %٢٥‬ﻣﻦ ﻣﻘﺎﻭﻣﺘﻪ ﻟﻠﻀﻐﻂ ﻭﺗﺘﺤﻤﻞ ﺍﳋﺮﺳﺎﻧﺔ ﰱ ﺍﻟﺸﺪ ﺣـﻮﺍﱃ ‪ %١٠‬ﻣـﻦ‬ ‫ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻠﻀﻐﻂ‪ .‬ﻭﻳﻜﻮﻥ ﺷﻜﻞ ﺍﻟﻜﺴﺮ ﰱ ﺍﳊﺪﻳﺪ ﺍﻟﺰﻫﺮ ﻭﺍﳋﺮﺳﺎﻧﺔ ﺍﻟﻌﺎﺩﻳﺔ ﻋﻤﻮﺩﻯ ﻋﻠـﻰ ﺍﶈـﻮﺭ‬ ‫ﺍﻟﻄﻮﱃ ﻟﻠﻜﻤﺮﺓ ﺑﻜﺎﻣﻞ ﻣﻘﻄﻊ ﺍﻟﻜﻤﺮﺓ ﺍﳌﺨﺘﱪﺓ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ .(٩-٤‬ﺃﻣﺎ ﺷﻜﻞ ﺍﻟﻜﺴﺮ ﰱ‬ ‫ﺍﻟﻜﻤﺮﺍﺕ ﻣﻦ ﺍﳋﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ ﻭﺍﳋﺸﺐ ﻓﻴﻜﻮﻥ ﺍﻻ‪‬ﻴﺎﺭ ﺑﺎﻟﺸﺪ ﺃﻭ ﺍﻟﺸﺪ ﺍﻟﻘﻄﺮﻱ ﺍﻟﻨﺎﺗﺞ ﻣﻦ ﺍﻟﻘـﺺ‬ ‫ﺃﻭ ﻣﻦ ﺇﺟﻬﺎﺩ ﺍﻟﻀﻐﻂ ﺃﺣﻴﺎﻧﹰﺎ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪.(٩-٤‬‬ ‫‪٨٨‬‬


‫ﺣﺪﻳﺪ ﺯﻫﺮ ﺃﻭ ﺧﺮﺳﺎﻧﺔ ﺑﺪﻭﻥ ﺣﺪﻳﺪ ﺗﺴﻠﻴﺢ‬

‫ﺍ‪‬ﻴﺎﺭ ﺷﺪ‬ ‫ﺧﺮﺳﺎﻧﺔ ‪‬ﺎ ﺣﺪﻳﺪ ﺗﺴﻠﻴﺢ ﻏﲑ ﻛﺎﻑ‬

‫ﺍ‪‬ﻴﺎﺭ ﺷﺪ‬ ‫ﺧﺮﺳﺎﻧﺔ ‪‬ﺎ ﺣﺪﻳﺪ ﺗﺴﻠﻴﺢ ﺯﺍﺋﺪ ﰱ ﻣﻨﻄﻘﺔ ﺍﻟﺸﺪ‬

‫ﺍ‪‬ﻴﺎﺭ ﺿﻐﻂ‬ ‫ﺧﺮﺳﺎﻧﺔ ‪‬ﺎ ﺣﺪﻳﺪ ﺗﺴﻠﻴﺢ ﻛﺎﻑ ﻋﻠﻮﻱ ﻭﺳﻔﻠﻲ‬

‫ﺍ‪‬ﻴﺎﺭ ﺷﺪ ﻗﻄﺮﻱ‬ ‫ﻛﻤﺮﺓ ﻣﻦ ﺍﳋﺸﺐ‬

‫ﺍ‪‬ﻴﺎﺭ ﻗﺺ ﺍﻷﺧﺸﺎﺏ‬

‫@@‬

‫‘‪@ @@ôŠàØÛa@õbä−üa@óÏ@òÐÜn‚½a@pbäîÈÜÛ@ŠØÛa@ÝØ‘@HYMTI@ÝØ‬‬

‫‪@ @@…‰bjÛa@óÜÇ@óärÛa@‰bjn@RMS@MT‬‬ ‫ﺍﺧﺘﺒﺎﺭ ﺍﻟﺜﲏ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻣﻄﻠﻮﺏ ﺑﻐﺮﺽ ﺍﻟﺘﺄﻛﺪ ﻣﻦ ﺗﻮﺍﺟﺪ ﺧﺎﺻﻴﺔ ﺍﳌﻤﻄﻮﻟﻴﺔ ﻟﻠﻤﻌﺎﺩﻥ ﻭﺩﺭﺍﺳﺔ ﺗـﺄﺛﲑ‬ ‫ﺍﳌﻌﺎﻣﻼﺕ ﻭﺍﳌﻌﺎﳉﺎﺕ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻠﻤﻌﺪﻥ ﻭﻧﺴﺐ ﺍﻹﺿﺎﻓﺎﺕ ﺃﻭ ﺍﻟﺸﻮﺍﺋﺐ ﻋﻠﻰ ﳑﻄﻮﻟﻴﺔ ﺍﳌﻌﺪﻥ‪ .‬ﻟﺬﻟﻚ‬ ‫ﺗﺘﻄﻠﺐ ﻣﻮﺍﺻﻔﺎﺕ ﻣﻌﻈﻢ ﺃﻧﻮﺍﻉ ﺍﻟﺼﻠﺐ ﺿﺮﻭﺭﺓ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺜﲏ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻋﻠﻰ ﺃﺳﻴﺎﺥ ﺣﺪﻳـﺪ‬ ‫ﺍﻟﺘﺴﻠﻴﺢ ﻟﻠﺨﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ ﻭﺻﻠﺐ ﻣﺴﺎﻣﲑ ﺍﻟﱪﺷﺎﻡ ﻭﺍﻟﺼﻠﺐ ﺍﻻﻧﺸﺎﺋﻲ ‪ ،‬ﻛﻤﺎ ﳚﺮﻯ ﺍﺧﺘﺒـﺎﺭ ﺍﻟـﺜﲎ‬ ‫ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻏﺎﻟﺒﹰﺎ ﻹﺧﺘﺒﺎﺭ ﳑﻄﻮﻟﻴﺔ ﺍﻟﻮﺻﻼﺕ ﺍﳌﻠﺤﻮﻣﺔ‪.‬‬ ‫‪٨٩‬‬


‫‪ -1‬‬ ‫ﲡﻬﺰ ﻗﻄﻊ ﺍﻹﺧﺘﺒﺎﺭ ﻣﻦ ﺍﻷﺳﻴﺎﺥ ﺃﻭ ﺍﻟﻘﻀﺒﺎﻥ ﺃﻭ ﺍﻷﺳﻼﻙ ﺑﺎﻟﻄﻮﻝ ﺍﳌﻨﺎﺳﺐ ﺍﻟﺬﻯ ﻳﺘﻮﺍﻓﻖ ﻣـﻊ ﻣﺎﻛﻴﻨـﺔ‬ ‫ﺍﻻﺧﺘﺒﺎﺭ ﺍﳌﺘﺎﺣﺔ ﻣﻊ ﻣﻼﺣﻈﺔ ﺗﺮﻙ ﺍﻟﻘﻄﺮ ﻟﻠﻌﻴﻨﺎﺕ ﺍﳌﺨﺘﻠﻔﺔ ﻛﻤﺎ ﻫﻮ ﻣﻮﺭﺩ ﻟﻼﺧﺘﺒﺎﺭ‪ .‬ﺃﻣﺎ ﺍﻷﻟﻮﺍﺡ ﻓﺘﺠﻬﺰ‬ ‫ﻗﻄﻊ ﺍﺧﺘﺒﺎﺭﻫﺎ ﺑﺘﺤﻀﲑ ﺷﺮﺍﺋﺢ ﺑﻄﻮﻝ ﻣﻨﺎﺳﺐ ﳌﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺑﻨﻔﺲ ﲰﻚ ﺍﻟﻠﻮﺡ‪.‬‬ ‫‪@ @@„bîþa@ëc@æbjšÔÛa@pbäîÇ@J‬‬ ‫ﻳﺘﻢ ﺗﺜﺒﻴﺘﻬﺎ ﺣﱴ ﻳﺘﻮﺍﺯﻯ ﻃﺮﻓﺎﻫﺎ ﻭﺗﻜﻮﻥ ﺍﻟﻌﻼﻗﺔ ﺑﲔ ﻗﻄﺮ ﺍﻟﻌﻴﻨﺔ )‪ (D‬ﻭﻧﺼﻒ ﳏﻮﺭ ﺍﻟـﺜﲎ )‪ (R‬ﻛﻤـﺎ‬ ‫ﻳﻠﻰ‪:‬‬ ‫‪ -‬ﺇﺫﺍ ﻛﺎﻥ ﻗﻄﺮ ﺍﻟﻘﻀﻴﺐ ≥ ‪ ٢,٥‬ﺳﻢ ﻓﺈﻥ‬

‫‪R=D‬‬

‫‪ -‬ﺇﺫﺍ ﻛﺎﻥ ﻗﻄﺮ ﺍﻟﻘﻀﻴﺐ ≤ ‪ ٢,٥‬ﺳﻢ ﻓﺈﻥ‬

‫‪R =1.5 D‬‬

‫‪@ @@aìÛþa@pbäîÇ@J‬‬ ‫ﳚﺮﻯ ﻫﺬﺍ ﺍﻻﺧﺘﺒﺎﺭ ﲤﺎﻣﹰﺎ ﻛﺎﻟﻘﻀﺒﺎﻥ ﻋﻠﻰ ﺃﻥ ﳛﻞ ﲰﻚ ﺍﻟﻠﻮﺡ )‪ (t‬ﳏﻞ ﻗﻄﺮ ﺍﻟﻘﻀﻴﺐ )‪.(D‬‬ ‫‪ -‬ﺇﺫﺍ ﻛﺎﻥ ﲰﻚ ﺍﻟﻠﻮﺡ ≥ ‪ ٢,٥‬ﺳﻢ ﻓﺈﻥ‬

‫‪R=t‬‬

‫‪ -‬ﺇﺫﺍ ﻛﺎﻥ ﲰﻚ ﺍﻟﻠﻮﺡ ≤ ‪ ٢,٥‬ﺳﻢ ﻓﺈﻥ‬

‫‪R =1.5 t‬‬

‫‪@ @òÔîÓŠÛa@aìÛþa@pbäîÇ@J‬‬ ‫ﻧﻈﺮﹰﺍ ﻟﺼﻌﻮﺑﺔ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺜﲏ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﺣﻮﻝ ﻗﻄﻌﺔ ﺇﺳﻄﻮﺍﻧﻴﺔ ﺑﻘﻄﺮ ﻳﺘﻤﺜﻞ ﺑﻌﻼﻗﺔ ﻣﻊ ﲰﻚ ﺍﻟﻠﻮﺡ‬ ‫ﺍﻟﺮﻗﻴﻖ ﻛﻤﺎ ﻫﻮ ﺍﳊﺎﻝ ﰱ ﺍﻟﻘﻀﺒﺎﻥ ﻭﺍﻷﻟﻮﺍﺡ‪ ،‬ﻭﻟﺬﻟﻚ ﻓﺈﻥ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺜﲏ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻭﺍﻷﻟـﻮﺍﺡ‬ ‫ﺍﻟﺮﻗﻴﻘﺔ ﻳﻜﻮﻥ ﺑﺜﲏ ﻗﻄﻌﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻠﻰ ﻧﻔﺴﻬﺎ‪.‬‬ ‫‪@ @Úýþa@pbäîÇ@J‬‬ ‫ﻳﺘﻢ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺜﲏ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻟﻸﺳﻼﻙ ﻭﺫﻟﻚ ﺑﺸﺪﻫﺎ ﺑﺴﻴﻄﹰﺎ ﰱ ﻭﺿﻊ ﺭﺃﺳﻰ ﰒ ﺛﻨﻴﻬﺎ ﺟﺎﻧﺒﻴﺎ ‪٩٠‬‬ ‫ﺩﺭﺟﺔ ﰒ ﺟﺎﻧﺒﻴﺒﹰﺎ ﰱ ﺍﻻﲡﺎﻩ ﺍﳌﻌﺎﻛﺲ ‪ ١٨٠‬ﺩﺭﺟﺔ ﰒ ﺇﻋﺎﺩ‪‬ﺎ ﺟﺎﻧﺒﻴﹰﺎ ﰱ ﺍﻻﲡـﺎﻩ ﺍﻷﻭﻝ ‪ ٩٠‬ﺩﺭﺟـﺔ ﺃﻯ‬ ‫ﻟﺘﺮﺟﻊ ﻟﻮﺿﻌﻬﺎ ﺍﻟﺮﺃﺳﻰ ﺍﻷﺻﻠﻰ ﻣﺮﺓ ﺃﺧﺮﻯ‪ ،‬ﻓﺈﺫﺍ ﱂ ﻳﻨﻜﺴﺮ ﺍﻟﺴﻠﻚ ﻳﻌﺘﱪ ﻣﻘﺒﻮ ﹰﻻ‪ .‬ﻭﳝﻜﻦ ﻣﻘﺎﺭﻧﺔ ﻣﺪﻯ‬ ‫ﲢﻤﻞ ﻗﻄﻌﺘﲔ ﻣﻦ ﺍﻟﺴﻠﻚ ﻟﻠﺜﲎ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﺑﺈﺟﺮﺍﺀ ﺍﻟﺜﲎ ﺟﺎﻧﺒﻴﹰﺎ ﻋﺪﺓ ﻣﺮﺍﺕ ﺣﱴ ﻛﺴﺮ ﺍﻟﺴﻠﻚ ﻓﻴﻜﻮﻥ‬ ‫ﻋﺪﺩ ﺍﻟﺪﻭﺭﺍﺕ ﺍﻟﱴ ﻛﺴﺮﺕ ﺍﻟﺴﻠﻚ ﻫﻮ ﻣﻘﻴﺎﺱ ﺃﺳﺎﺳﻲ ﻟﻠﻤﻘﺎﺭﻧﺔ ﺑﲔ ﺍﻟﺴﻠﻜﲔ ﺍﳌﺨﺘﻠﻔﲔ‪.‬‬

‫‪ & '& () -2‬‬ ‫ﳚﺮﻯ ﻫﺬﺍ ﺍﻻﺧﺘﺒﺎﺭ ﺇﻣﺎ ﺑﺜﲏ ﺍﻟﻌﻴﻨﺔ ﺣﻮﻝ ﳏﻮﺭﻫﺎ ﺣﱴ ﻳﺘﻮﺍﺯﻯ ﻃﺮﻓﺎﻫﺎ ﺃﻭ ﳚﺮﻯ ﺑﺎﺳـﺘﺨﺪﺍﻡ ﻣﺎﻛﻴﻨـﺎﺕ‬ ‫ﺍﻻﳓﻨﺎﺀ ﺃﻭ ﻣﺎﻛﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﺍﻟﻌﺎﻣﺔ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪.(١٠-٤‬‬ ‫‪٩٠‬‬


‫‪P‬‬ ‫‪‰bjnüa@òäîÇ‬‬

‫‪D‬‬ ‫‪R=1 : 1.5 D‬‬

‫‪R‬‬ ‫‪ñŒî×‰‬‬

‫‪ñŒî×‰‬‬ ‫‪4:5D‬‬

‫‘‪@ @@òßbÈÛa@‰bjnüa@òäî×b¶@…‰bjÛa@óÜÇ@óärÛa@‰bjna@õaŠug@HQPMTI@ÝØ‬‬ ‫@@‬ ‫@@‬

‫‪ & ' ! -3‬‬ ‫ﳛﺪﺙ ﺍ‪‬ﻴﺎﺭ ﻟﻠﻤﻮﺍﺩ ﺍﳌﻄﻴﻠﺔ ﰱ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺜﲏ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻧﺘﻴﺠﺔ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﺸﺪ ﺃﻭ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﻀﻐﻂ ﺃﻭ‬ ‫ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﺺ ﺃﻭ ﺑﺎﻟﺘﺸﻘﻖ ﻭﺍﻟﻜﺴﺮ ﻧﺘﻴﺠﺔ ﻟﻌﺪﻡ ﲡﺎﻧﺴﻬﺎ ﻭﺫﻟﻚ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﳊـﺎﻻﺕ ﺍﳌﺒﻴﻨـﺔ‬ ‫ﺑﺸﻜﻞ ) ‪.(١١-٤‬‬ ‫ﺷﺮﻭﺥ ﻧﺘﻴﺠﺔ ﺍﻟﻀﻐﻂ‬

‫ﺷﺮﻭﺥ ﻧﺘﻴﺠﺔ ﺍﻟﻘﺺ‬

‫@@‬ ‫@@‬ ‫@@‬ ‫@@‬

‫ﺷﺮﻭﺥ ﻧﺘﻴﺠﺔ ﺍﻟﺸﺪ‬

‫@@‬ ‫@@‬ ‫‘‪@ @@…‰bjÛa@óÜÇ@óärÛa@‰bjna@óÏ@òÜîĐ½a@…aì½a@‰bîèãa@HQQMTI@ÝØ‬‬

‫@@‬ ‫‪٩١‬‬


‫‪@ @@æ…bÈàÜÛ@ôŠc@q@pa‰bjna@SMS@MT‬‬ ‫ﻳﺘﻢ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭﺍﺕ ﺍﺧﺮﻯ ﻋﻠﻰ ﺍﳌﻌﺎﺩﻥ ﻏﲑ ﺍﻟﺜﲏ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻷﻏﺮﺍﺽ ﺃﺧﺮﻯ ﻣﺘﻨﻮﻋﺔ ﻭﻣﻨﻬﺎ‪:‬‬ ‫‪ -١‬ﺍﺧﺘﺒﺎﺭ ﺍﻟﺜﲎ ﻋﻠﻰ ﺍﻟﺴﺎﺧﻦ )‪(Hot bend test‬‬ ‫ﻳﺘﻢ ﺇﺟﺮﺍﺀ ﻫﺬﺍ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻠﻰ ﺍﳊﺪﻳﺪ ﺍﳌﻄﺎﻭﻉ ﻛﻤﺎﺩﺓ ﻣﻄﻴﻠﺔ ﻟﺒﻴﺎﻥ ﻛﻤﻴﺔ ﺍﻟﻜﱪﻳﺖ ﺑﻪ ﻭﺍﻟﱴ ﺗﺴﺒﺐ ﰱ‬ ‫ﻗﻠﺔ ﳑﻄﻮﻟﻴﺘﺔ ﺑﺸﻜﻞ ﻛﺒﲑ ﻋﻨﺪ ﺩﺭﺟﺎﺕ ﺍﳊﺮﺍﺭﺓ ﺍﻟﻌﺎﻟﻴﺔ‪ .‬ﺣﻴﺚ ﻳﺘﻢ ﺇﺟﺮﺍﺀ ﺍﻻﺧﺘﺒﺎﺭ ﺑﺘﺴﺨﲔ ﺍﻟﻌﻴﻨﺔ ﻋﻨﺪ‬ ‫ﺩﺭﺟﺔ ﺍﻟﻠﺤﺎﻡ ﻭﻫﻰ ﺣﻮﺍﱃ ‪ ٨٨٠‬ﺩﺭﺟﺔ ﻣﺌﻮﻳﺔ ﰒ ﺛﲏ ﺍﻟﻘﻄﻌﺔ ﺍﳌﺴﺨﻨﺔ ﻋﻠﻰ ﺳﻨﺪﺍﻥ‪.‬‬ ‫‪ -٢‬ﺍﺧﺘﺒﺎﺭ ﺛﲏ ﺍﻟﺘﺴﻘﻴﺔ )‪(Quenck bend test‬‬ ‫ﻭﳚﺮﻯ ﻫﺬﺍ ﺍﻻﺧﺘﺒﺎﺭ ﻟﺼﻠﺐ ﻣﺴﺎﻣﲑ ﺍﻟﱪﺷﺎﻡ ‪ ،‬ﻭﺫﻟﻚ ﺑﺘﺴﺨﲔ ﺍﻟﺼﻠﺐ ﻭﺗﺴﻘﻴﺘﻪ ﰒ ﺛﻨﻴﻪ ﻭﻳﻬﺪﻑ ﻫﺬﺍ‬ ‫ﺍﻻﺧﺘﺒﺎﺭ ﳌﻌﺮﻓﺔ ﻛﻤﻴﺔ ﺍﻟﻜﺮﺑﻮﻥ ﺍﻟﻌﺎﻟﻴﺔ ﻭﺍﻟﱴ ﺗﺴﺒﺐ ﰱ ﻧﻘﺺ ﻛﺒﲑ ﰱ ﳑﻄﻮﻟﻴﺔ ﺍﻟﺼﻠﺐ ﺍﳌﺨﺘﱪ‪.‬‬ ‫‪ -٣‬ﺍﺧﺘﺒﺎﺭ ﺛﲎ ﺣﺮ )‪(Nick bend test‬‬ ‫ﻭﻳﺘﻢ ﺇﺟﺮﺍﺀ ﻫﺬﺍ ﺍﻻﺧﺘﺒﺎﺭ ﰱ ﺣﺎﻟﺔ ﺇﺫﺍ ﺃﺭﻳﺪ ﺃﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺳﺮﻳﻊ ﻟﻠﻤﻌﺎﺩﻥ ﻟﺒﻴﺎﻥ ﻣﻌﺮﻓﺔ ﺣﺠﻢ ﺟﺰﻳﺌﺎ‪‬ـﺎ‬ ‫ﻭﻋﻴﻮ‪‬ﺎ ﺍﻟﺪﺍﺧﻠﻴﺔ ﻭﺍﻟﱴ ﺗﺴﺒﺐ ﰱ ﻧﻘﺺ ﺍﳌﻤﻄﻮﻟﻴﺔ ﻟﻠﻤﻌﺪﻥ ﺍﳌﻄﻠﻮﺏ ﺍﺳﺘﺨﺪﺍﻣﻪ‪ .‬ﺣﻴﺚ ﺃﻧﻪ ﻳـﺘﻢ ﺣـﺰ‬ ‫ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﺑﺄﺯﻣﻴﻞ ﺃﻭ ﻣﻨﺸﺎﺭ ﻣﻌﺎﺩﻥ ﺃﻭ ﻣﺎﻛﻴﻨﺔ ﺗﻔﺮﻳﺰ ﰒ ﻳﺘﻢ ﺍﻟﻄﺮﻕ ﻋﻠﻴﻬﺎ ﺃﻭ ﺍﻟﻀﻐﻂ ﻋﻠﻴﻬـﺎ ﺑـﺄﻯ‬ ‫ﻣﺎﻛﻴﻨﺔ ﺇﺧﺘﺒﺎﺭ ﻹﲤﺎﻡ ﺍﻻﺧﺘﺒﺎﺭ‪.‬‬

‫‪٩٢‬‬


‫ ‬ ‫ ‬

‫‪ 1-5‬‬

‫ﺗﻌﺘﱪ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻮﺍﺩ ﻟﻠﻘﺺ ﻣﺴﺄﻟﺔ ﺿﺮﻭﺭﻳﺔ ﻭﻫﺎﻣﺔ ﰱ ﺗﺼﻤﻴﻢ ﺍﳌﻨﺸﺂﺕ ﻭﻋﻨﺎﺻـﺮﻫﺎ ﻣﺜـﻞ ﺍﻟﻮﺻـﻼﺕ‬ ‫ﺍﳌﱪﴰﺔ )‪ (Riveted Jointed‬ﻭﺍﻟﻮﺻﻼﺕ ﺍﳌﻠﺤﻮﻣـﺔ )‪ (Welded Joints‬ﻭﺍﻟﻜﻤـﺮﺍﺕ ﺍﳌﻌﺪﻧﻴـﺔ‬ ‫ﻭﺍﳋﺮﺳﺎﻧﻴﺔ‪ .‬ﻭﺗﻈﻬﺮ ﺃﳘﻴﺔ ﺍﻟﻘﺺ ﰱ ﺃﻥ ﻣﻘﺎﻭﻣﺔ ﺍﳌﺎﺩﺓ ﻟﻠﻘﺺ ﻫﻰ ﺍﻟﱴ ﺗﺘﺤﻜﻢ ﰱ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻮﺍﺩ ﺍﳌﻄﻴﻠـﺔ‬ ‫ﻟﻘﻮﻯ ﺍﻟﺸﺪ ﻛﺬﻟﻚ ﰱ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﻟﻘﻮﻯ ﺍﻟﻀﻐﻂ‪ ،‬ﺣﻴﺚ ﺃﻧﻪ ﻗﺪ ﺗﺒﲔ ﰱ ﺍﻷﺑﻮﺍﺏ ﺍﻟﺴﺎﺑﻘﺔ ﺃﻥ‬ ‫ﻛﺴﺮ ﺗﻠﻚ ﺍﳌﻮﺍﺩ ﲢﺖ ﻗﻮﻯ ﺍﻟﺸﺪ ﺃﻭ ﺍﻟﻀﻐﻂ ﻳﻜﻮﻥ ﰱ ﺃﻏﻠﺐ ﺍﻷﺣﻴﺎﻥ ﻣﻦ ﺗﺄﺛﲑ ﻗﻮﻯ ﺍﻟﻘﺺ‪ .‬ﻭﺍﻟﻘﺺ‬ ‫ﻫﻮ ﺣﺎﻟﺔ ﺇﻧﺰﻻﻕ ﺟﺰﺀ ﻣﻦ ﺍﳌﺎﺩﺓ ﻋﻠﻰ ﺟﺎﻧﺐ ﻣﻦ ﻣﻘﻄﻊ ﻣﺴﺘﻌﺮﺽ ﻣﻌﲔ ﻋﻠﻰ ﺑﺎﻗﻰ ﺍﳌﺎﺩﺓ ﺍﻟﻮﺍﻗﻊ ﻋﻠـﻰ‬ ‫ﺍﳉﺎﻧﺐ ﺍﻵﺧﺮ ﻣﻦ ﺍﳌﻘﻄﻊ ﻭﻳﻜﻮﻥ ﺫﻟﻚ ﻧﺘﻴﺠﺔ ﺗﺄﺛﲑ ﻗﻮﻯ ﺍﻟﻘﺺ ﺃﻭ ﺗﺄﺛﲑ ﻋﺰﻭﻡ ﺍﻹﻟﺘﻮﺍﺀ‪ .‬ﻭﺍﻟﻘﻮﻯ ﺍﻟـﱴ‬ ‫ﺗﺴﺒﺐ ﺍﻟﻘﺺ ﻫﻲ ﺍﻟﱴ ﺗﺆﺛﺮ ﰱ ﺍﲡﺎﻩ ﻣﻮﺍﺯﻱ ﻟﻠﻤﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﺠﺴﻢ ﻭﻳﻨﺘﺞ ﻋﻦ ﻫﺬﻩ ﺍﻟﻘﻮﻯ ﺗﺸﻜﻞ‬ ‫ﺑﺎﻧﺰﻻﻕ ﺃﺟﺰﺍﺀ ﺍﳉﺴﻢ ﻣﻮﺍﺯﻳﺔ ﻻﲡﺎﻩ ﻗﻮﺓ ﺍﻟﻘﺺ‪ .‬ﻭﻏﺎﻟﺒﹰﺎ ﲢﺪﺙ ﺣﺎﻟﺔ ﺍﻟﻘﺺ ﻣﻦ ﺗﺄﺛﲑ ﻗﻮﻯ ﺍﻟـﻀﻐﻂ ﺃﻭ‬ ‫ﺍﻟﺸﺪ ﻭﺗﺴﻤﻰ ﺑﺎﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ ﺃﻭ ﻣﻦ ﺗﺄﺛﲑ ﺍﻟﻘﻮﻯ ﺍﳌﺴﺒﺒﺔ ﻟﻼﳓﻨﺎﺀ ﻭﺗﺴﻤﻰ ﻗﺺ ﺍﻻﳓﻨﺎﺀ‪ ،‬ﻭﺃﻳﻀﺎ ﲢـﺪﺙ‬ ‫ﺣﺎﻟﺔ ﺍﻟﻘﺺ ﺍﳋﺎﻟﺺ ﲢﺖ ﺗﺄﺛﲑ ﻋﺰﻭﻡ ﺍﻻﻟﺘﻮﺍﺀ ﻭﺍﳌﺴﺒﺒﺔ ﻻﻧﺰﻻﻕ ﺍﳌﻘﺎﻃﻊ ﺍﳌﺴﺘﻌﺮﺿﺔ ﻟﻠﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻋﻠﻰ‬ ‫ﺑﻌﻀﻬﺎ ﺍﻟﺒﻌﺾ ﻏﲑ ﻣﺼﺤﻮﺑﺔ ﺑﻌﺰﻡ ﺍﳓﻨﺎﺀ ﻛﻤﺎ ﰱ ﺣﺎﻟﺔ ﺍﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ ﻭﻳﺴﻤﻰ ﻗﺺ ﺍﻻﻟﺘﻮﺍﺀ‪.‬‬ ‫ﻭﺗﻨﺤﺼﺮ ﺃﻧﻮﺍﻉ ﺍﻟﻘﺺ ﻋﻤﻮﻣﹰﺎ ﰱ ﺍﻷﻧﻮﺍﻉ ﺍﻵﺗﻴﺔ‪:‬‬ ‫‪@ @@Š;;;‘bjß@—Ó@@ @MQ‬‬ ‫‪@ @@õbä−üa@—Ó@@ @MR‬‬ ‫‪@ @@õaì;nÛüa@—Ó@@ @MS‬‬

‫‪ ! 2-5‬‬

‫ﳛﺪﺙ ﺍﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ ﻋﻨﺪﻣﺎ ﻧﺆﺛﺮ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﺑﻘﻮﻯ ﻣﻮﺍﺯﻳﺔ ﺃﻭ ﳑﺎﺳـﺔ ﳍـﺬﺍ‬ ‫ﺍﳌﻘﻄﻊ ﰱ ﺍﲡﺎﻩ ﺭﺃﺳﻰ ﺃﻭ ﺃﻓﻘﻰ ﺃﻭ ﻣﺎﺋﻞ ﺑﺸﺮﻁ ﻋﺪﻡ ﻭﺟﻮﺩ ﻻ ﻣﺮﻛﺰﻳﺔ ﰱ ﲪﻞ ﺍﻟﻘـﺺ ﻟﻠﻮﺻـﻮﻝ ﺇﱃ‬ ‫ﺍﻟﻘﺺ ﺍﳋﺎﻟﺺ ﻭﺍﻟﺬﻯ ﳛﺪﺙ ﻣﻦ ﺗﺄﺛﲑ ﻗﻮﺗﲔ ﻣﺘﻮﺍﺯﻳﺘﲔ ﺍﳌﺴﺎﻓﺔ ﺑﻴﻨﻬﻤﺎ ﻣﻌﺪﻭﻣﺔ‪ ،‬ﺃﻯ ﻗﻮﺗﲔ ﳍﻤﺎ ﻧﻔـﺲ‬ ‫ﺧﻂ ﺍﻟﺘﺄﺛﲑ ﻭﺍﻟﺬﻯ ﻳﻘﻊ ﰱ ﻧﻔﺲ ﻣﺴﺘﻮﻯ ﻣﻘﻄﻊ ﺍﻟﻌﻴﻨﺔ ﻭﻟﻜﻦ ﺗﻠﻚ ﺍﻟﻘﻮﺗﲔ ﻣﺘﻌﺎﻛﺴﺘﲔ ﰱ ﺍﻻﲡﺎﻩ ﻛﻤـﺎ‬ ‫ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪.(١-٥‬‬ ‫‪٩٣‬‬


‫‪Q‬‬ ‫‪Q‬‬ ‫‪e‬‬ ‫‪P‬‬

‫‪A= ab‬‬ ‫‪Q = P/A = P/ab‬‬

‫‪a‬‬

‫‪b‬‬

‫@@‬ ‫‪P‬‬ ‫@@‬

‫‘‪@ @—Ûbä@—ÔÛaë@Š‘bj½a@—ÔÛa@@HQMUI@ÝØ‬‬

‫ﻏﺎﻟﺒﹰﺎ ﺣﺪﻭﺙ ﺍﻟﻘﺺ ﺍﳋﺎﻟﺺ ﲢﺖ ﺗﺄﺛﲑ ﻗﻮﻯ ﺍﻟﺸﺪ ﺃﻭ ﺍﻟﻀﻐﻂ ﻧﺎﺩﺭ ﺣﺪﻭﺛﻪ ﻋﻤﻠﻴﺎﹰ‪ ،‬ﻷﻧﻪ ﻻﺑـﺪ ﻣـﻦ‬ ‫ﻭﺟﻮﺩ ﻣﺴﺎﻓﺔ ﺑﲔ ﻗﻮﺗﲔ ﺍﻟﺸﺪ ﺃﻭ ﺍﻟﻀﻐﻂ ﻭﻟﻮ ﺑﺴﻴﻄﺔ ﻭﺍﳌﺴﺒﺒﺔ ﰱ ﺣﺪﻭﺙ ﻗﺺ ﲟﻘﻄﻊ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘـﱪﺓ‬ ‫ﻛﻤﺎ ﻫﻮ ﺍﳊﺎﻝ ﺑﺎﻟﻮﺻﻠﺔ ﺍﳌﱪﴰﺔ ﺍﳌﻮﺿﺤﺔ ﺑﺎﻟﺸﻜﻞ )‪ (١-٥‬ﻟﺬﻟﻚ ﺗﺴﻤﻰ ﺣﺎﻟﺔ ﺍﻟﻘﺺ ﰱ ﻫﺬﻩ ﺍﻟﻮﺻﻠﺔ‬ ‫ﺍﳌﱪﴰﺔ ‪ Š@ ‘bj½a@—ÔÛbi‬ﺣﻴﺚ ﻳﺘﻌﺮﺽ ﻣﻘﻄﻊ ﻣﺴﻤﺎﺭ ﺍﻟﱪﺷﺎﻡ ﺇﱃ ﻗﻮﺓ ﻗﺺ )‪ (Q‬ﻭﻋﺰﻡ ﺍﳓﻨﺎﺀ ﻭﻟﻮ ﺻﻐﲑ‬ ‫)‪ ،(Q.e‬ﻭﺣﻴﺚ ﺃﻧﻪ ﳝﻜﻦ ﻋﻤﻠﻴﺎ ﺇﳘﺎﻝ ﺗﺄﺛﲑﻩ ﻭﺑﺬﻟﻚ ﻧﻌﺘﱪ ﻗﻮﺓ ﺍﻟﻘﺺ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﺍﳌـﺴﺘﻌﺮﺽ‬ ‫ﻣﻮﺯﻋﺔ ﺗﻮﺯﻳﻌﺎ ﻣﺘﺴﺎﻭﻳﹰﺎ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﻓﺘﺤﺪﺙ ﺇﺟﻬﺎﺩ ﻗﺺ ﻗﻴﻤﺘﻪ ﻛﻤﺎ ﻳﻠﻰ‪:‬‬ ‫‪Q‬‬ ‫‪D2/4‬‬

‫‪π‬‬

‫=‬

‫‪P‬‬ ‫‪A‬‬

‫=‪q‬‬

‫— ﻓﺈﻧﻪ ﳝﻜﻦ ﺍﻟﺘﻮﺻﻞ ﺇﻟﻴﻪ ﻋﻦ ﻃﺮﻳﻖ ﲡﻬﻴﺰ ﺍﻟﻌﻴﻨﺔ ﻋﻠﻰ ﺷﻜﻞ ﺣﺮﻑ ) ‪ ( S‬ﻟﻜﻰ ﻧﺮﻛﺰ ﺗﺄﺛﲑ‬ ‫ﺃﻣﺎ ‪@ Ûb;ä@—ÔÛa‬‬ ‫ﻗﻮﺗﲔ ﺍﻟﻘﺺ ﻋﻠﻰ ﺧﻂ ﺗﺄﺛﲑ ﻭﺍﺣﺪ ﺑﺘﻮﺯﻳﻊ ﻣﻨﺘﻈﻢ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﺍﳌﻌﺮﺽ ﻟﻘﻮﻯ ﺍﻟﻘـﺺ ﻛﻤـﺎ ﻫـﻮ ﻣﻮﺿـﺢ‬ ‫ﺑﺎﻟﺸﻜﻞ)‪ (١-٥‬ﻭﺗﻜﻮﻥ ﻗﻴﻤﺔ ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﺍﳋﺎﻟﺺ ﻫﻨﺎ ﻛﻤﺎ ﻳﻠﻲ‪:‬‬ ‫‪Q‬‬ ‫‪a.b‬‬

‫‪ Š‘bj½a@—ÔÜÛë‬ﺃﻧﻮﺍﻉ ﳐﺘﻠﻔﺔ ﻣﻨﻬﺎ‪:‬‬ ‫ ﺍﻟﻘﺺ ﺍﳌﻔﺮﺩ‪.‬‬‫ ﺍﻟﻘﺺ ﺍﳌﺰﺩﻭﺝ‪.‬‬‫‪ -‬ﺍﻟﻘﺺ ﺍﻟﺜﺎﻗﺐ‪.‬‬

‫‪٩٤‬‬

‫=‬

‫‪P‬‬ ‫‪A‬‬

‫=‪q‬‬


‫‪@ @@…ŠÐ½a@—ÔÛa@@QMRMU‬‬ ‫ﻳﺴﻤﻰ ﺍﻟﻘﺺ ﺍﳌﻔﺮﺩ ﺑﺬﻟﻚ ﻷﻥ ﻗﻮﻯ ﺍﻟﻘﺺ ﺗﺆﺛﺮ ﻋﻠﻰ ﻣﻘﻄﻊ ﻣﺴﺘﻌﺮﺽ ﻭﺍﺣﺪ ﻓﻘﻂ ﻣﻦ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ‬ ‫ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ .(٢-٥‬ﻭﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﺍﳌﻔﺮﺩ ﻫﺬﺍ ﻳﺴﺎﻭﻯ ﻗﻮﺓ ﺍﻟﻘـﺺ ﻣﻘـﺴﻮﻣﺔ ﻋﻠـﻰ‬ ‫ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﳌﻘﺎﻭﻡ ﻟﻘﻮﻯ ﺍﻟﻘﺺ‪.‬‬

‫‪Q‬‬ ‫=‬ ‫‪A‬‬

‫‪P‬‬ ‫‪q= A‬‬

‫‪a‬‬ ‫‪P‬‬ ‫‪b‬‬

‫‪b‬‬

‫‪a‬‬ ‫‪P‬‬ ‫‪Q = P/A = P / ab‬‬

‫@@‬ ‫‘‪@ @@…ŠÐ½a@—ÔÛa@püby@HRMU@I@ÝØ‬‬

‫@@‬ ‫‪@ @@xë…Œ½a@—ÔÛa@RMRMU‬‬ ‫ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ ﻳﺴﻤﻰ ﺍﻟﻘﺺ ﺍﳌﺰﺩﻭﺝ ﻷﻧﻪ ﻳﻘﺎﻭﻡ ﺗﺄﺛﲑ ﻗﻮﻯ ﺍﻟﻘﺺ ﲟﻘﻄﻌﺎﻥ ﻣﺴﺘﻌﺮﺿﺎﻥ‬ ‫ﻣﻦ ﺍﻟﻌﻴﻨﺔ ﺃﻭ ﺍﳉﺴﻢ ﺍﳌﺨﺘﱪ ﻛﻤﺎ ﻫﻮ ﻣﺒﲔ ﺑﺎﻟﺸﻜﻞ )‪ ،(٣-٥‬ﻭﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﺍﳌﺰﺩﻭﺝ ﻳـﺴﺎﻭﻯ ﻗـﻮﺓ‬ ‫ﺍﻟﻘﺺ ﻋﻠﻰ ﺍﳌﺴﺎﺣﺔ ﺍﳌﻘﺎﻭﻣﺔ ﳍﺬﻩ ﺍﻟﻘﻮﺓ ﺃﻯ ﺃﻥ‪:‬‬ ‫‪Q‬‬ ‫‪P‬‬ ‫‪= 2A‬‬ ‫‪2A‬‬

‫=‪q‬‬

‫‪P‬‬ ‫‪b‬‬ ‫‪a‬‬

‫‪A= 2ab‬‬ ‫‪Q = P/A = P / 2ab‬‬

‫@@‬

‫‪P/2‬‬

‫‪@ @P‬‬ ‫‪Q=P/2A‬‬

‫@@‬ ‫‪P/2‬‬

‫‪P/2‬‬

‫@@‬

‫‘‪@ @xë…Œ½a@—ÔÛa@püby@HSMUI@ÝØ‬‬

‫‪٩٥‬‬

‫‪P/2‬‬ ‫‪A‬‬


‫ﻛﻤﺎ ﺃﻧﻪ ﳚﺐ ﺃﻥ ﻧﻼﺣﻆ ﺃﻧﻪ ﻣﻘﺎﻭﻣﺔ ﺍﳌﺎﺩﺓ ﺍﻟﻮﺍﺣﺪﺓ ﻟﻘﻮﺓ ﺍﻟﻘﺺ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻮﺣﺪﺓ ﺍﳌﺴﺎﺣﺔ ﺛﺎﺑﺘـﺔ ﻓـﺈﻥ‬ ‫ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﺍﳌﻔﺮﺩ ﻳﺴﺎﻭﻯ ﻧﻈﺮﻳﺎ ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﺍﳌﺰﺩﻭﺝ‪ .‬ﻟﺬﻟﻚ ﻓﺈﻧﻨﺎ ﻧﻼﺣﻆ ﺃﻧﻪ ﺇﺫﺍ ﰎ ﻛﺴﺮ ﻣﺴﻤﺎﺭ‬ ‫ﺍﻟﱪﺷﺎﻡ ﺍﳌﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ (٢-٥‬ﲢﺖ ﺗﺄﺛﲑ ﻗﺺ ﻣﻔﺮﺩ ﺑﻘﻮﺓ ﻗﺺ )‪ ،(Q‬ﰒ ﺗﻌﺮﺽ ﻣـﺴﻤﺎﺭ ﺑﺮﺷـﺎﻡ‬ ‫ﺁﺧﺮ ﻣﻦ ﻧﻔﺲ ﻣﻌﺪﻥ ﺍﳌﺴﻤﺎﺭ ﺍﻟﺴﺎﺑﻖ ﻭﺑﻨﻔﺲ ﺃﺑﻌﺎﺩﻩ ﻟﻘﺺ ﻣﺰﺩﻭﺝ ﺣﱴ ﺍﻟﻜﺴﺮ ﻭﻛﺎﻧﺖ ﺍﻟﻘﻮﺓ ﺍﳌﺴﺒﺒﺔ‬ ‫ﻟﻠﻜﺴﺮ )‪ (Qd‬ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ ،(٣-٥‬ﻓﺈﻥ‪:‬‬ ‫‪Qd = 2 Q‬‬

‫ﻭﺫﻟﻚ ﻷﻥ‪:‬‬

‫‪Qd‬‬ ‫=‬ ‫‪2A‬‬

‫‪Q‬‬ ‫‪A‬‬

‫=‪q‬‬

‫‪@ @@kÓbrÛa@—ÔÛa@SMRMU‬‬ ‫ﻋﻨﺪﻣﺎ ﺗﺘﻌﺮﺽ ﻋﻴﻨﺔ ﻟﻘﻮﺓ ﺿﻐﻂ ﻟﻜﻰ ﲢﺪﺙ ﺑﺘﻠﻚ ﺍﻟﻌﻴﻨﺔ ﺛﻘﺐ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ (٤-٥‬ﻓـﺈﻥ‬ ‫ﻫﺬﻩ ﺍﻟﻌﻴﻨﺔ ﺗﻨﻜﺴﺮ ﲢﺖ ﺗﺄﺛﲑ ﺇﺟﻬﺎﺩﻳﻦ ﳘﺎ‪:‬‬ ‫‪ ÁÌ™@…bèug‬ﻳﺆﺛﺮ ﻋﻠﻰ ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﶈﻤﻠﺔ ﻭﻳﺴﺎﻭﻯ‪:‬‬

‫‪P‬‬ ‫‪πD2/4‬‬

‫‪P‬‬ ‫=‪σ= A‬‬

‫— ﻳﺆﺛﺮ ﻋﻠﻰ ﺍﳌﺴﺎﺣﺔ ﺍﳉﺎﻧﺒﻴﺔ ﶈﻴﻂ ﻣﻘﻄﻊ ﺍﻟﺘﺄﺛﲑ )ﺍﳌﺴﺎﺣﺔ ﺍﳉﺎﻧﺒﻴﺔ ﻟﻠﻘﺮﺹ ﺍﳌﺜﻘﻮﺏ( ﻭﻳﺴﻤﻰ‬ ‫‪@ Ó@…bèug‬‬ ‫ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﺍﻟﺜﺎﻗﺐ ﻭﻳﺴﺎﻭﻱ‪:‬‬

‫‪P‬‬ ‫‪π.D.t‬‬

‫‪P‬‬

‫@@‬ ‫‪t‬‬

‫‪q = p/2π‬‬ ‫‪πdt‬‬

‫@@‬ ‫@@‬ ‫@@‬ ‫@ @‪d‬‬

‫@@‬ ‫‘‪@ @kÓbrÛa@—ÔÛa@òÛby@HTMUI@ÝØ‬‬

‫@@‬ ‫‪٩٦‬‬

‫‪P‬‬ ‫=‬ ‫‪Side Area‬‬

‫=‪q‬‬


‫‪@ @Š‘bj½a@—ÔÛa@pa‰bjna@TMRMU‬‬ ‫ﺇﻥ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ ﻟﻠﻤﻌﺎﺩﻥ ﻻ ﺗﻨﺺ ﻋﻠﻴﻪ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻛﺎﺧﺘﺒﺎﺭ ﻗﺒﻮﻝ ﺃﻭ ﺭﻓﺾ ﻟﻠﻤـﻮﺍﺩ‬ ‫ﺇﻻ ﰱ ﺑﻌﺾ ﺍﳊﺎﻻﺕ ﺍﳋﺎﺻﺔ ﻣﺜﻞ ﺍﳌﻌﺎﺩﻥ ﺍﻟﱴ ﺗﻌﻤﻞ ﰱ ﺍﳌﻨﺸﺄ ﻛﻤﺴﺎﻣﲑ ﺑﺮﺷﺎﻡ ﺃﻭ ﻛﺄﺩﺍﺓ ﻟﻮﺻﻞ ﺃﺟﺰﺍﺀ‬ ‫ﺍﳌﻨﺸﺂﺕ ﻭﺍﳌﺎﻛﻴﻨﺎﺕ ﻭﻳﻘﻊ ﻋﻠﻴﻬﺎ ﻗﺺ ﻣﺒﺎﺷﺮ ﻣﻔﺮﺩ ﺃﻭ ﻣﺰﺩﻭﺝ ﻭﺫﻟﻚ ﻷﻥ ﺍﳌﻌﺎﺩﻥ ﻭﺧﺼﻮﺻﺎ ﺍﳌﻄﻴﻠـﺔ‬ ‫ﻣﻨﻬﺎ ﻳﻜﺘﻔﻰ ﻓﻴﻬﺎ ﺑﺈﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻟﺘﻌﻴﲔ ﺧﻮﺍﺹ ﺍﳌﻌﺪﻥ ﺑﺪﻗﺔ ﻭﻫﺬﺍ ﻷﻥ ﻛﺴﺮ ﺍﳌﻌﺪﻥ ﰱ ﺍﻟـﺸﺪ ﺑـﺴﺒﺐ‬ ‫ﺿﻌﻔﻪ ﰱ ﲢﻤﻞ ﺍﻟﻘﺺ ﺃﻯ ﺃﻥ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻟﻠﻤﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﺗﺴﺘﺨﺪﻡ ﻟﻠﻤﻘﺎﺭﻧﺔ ﺑﲔ ﺍﳌﻌﺎﺩﻥ ﻋﻦ ﻣﻘﺎﻭﻣﺔ‬ ‫ﺍﻟﻘﺺ‪ ،‬ﺣﻴﺚ ﺃﻥ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﻟﻠﻘﺺ ﺃﻗﻞ ﻣﻦ ﻣﻘﺎﻭﻣﺘﻪ ﻟﻠﺸﺪ ﻭﺗﺴﺎﻭﻯ ﺣﻮﺍﱃ ) ‪ (٠,٨‬ﻣـﻦ‬ ‫ﻣﻘﺎﻭﻣﺘﻪ ﻟﻠﺸﺪ‪ .‬ﻛﻤﺎ ﻳﻼﺣﻆ ﺃﻥ ﺍﳌﻌﺎﺩﻥ ﺍﻟﻘﺼﻔﺔ ﺿﻌﻴﻔﺔ ﰱ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻋﻦ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻘﺺ‪ ،‬ﺣﻴﺚ ﺃﻥ‬ ‫ﺍﳌﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﺗﻨﻜﺴﺮ ﻋﻨﺪ ﻗﻮﻯ ﺍﻟﺸﺪ ﻷﻥ ﻣﻘﺎﻭﻣﺔ ﺗﻠﻚ ﺍﳌﻮﺍﺩ ﻟﻠﻘﺺ ﺗﺴﺎﻭﻯ ﺣـﻮﺍﱃ )‪ (١,٣٠‬ﻣـﻦ‬ ‫ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻠﺸﺪ‪ .‬ﻟﺬﻟﻚ ﻓﺈﻧﻪ ﻟﻴﺲ ﻣﻦ ﺍﻟﻀﺮﻭﺭﻱ ﺇﺟﺮﺍﺀ ﺇﺧﺘﺒﺎﺭ ﺍﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ ﻋﻠﻰ ﺍﳌـﻮﺍﺩ ﺍﻟﻘـﺼﻔﺔ‪.‬‬ ‫ﻭﳝﻜﻦ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ ﻟﻠﻤﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ﺍﳌﻄﻴﻠﺔ ﺑﺘﻌﺮﻳﺾ ﺍﻟﻌﻴﻨﺔ ﻟﻘﻮﻯ ﺷﺪ ﺃﻭ ﺿﻐﻂ ﺗـﺴﺒﺐ‬ ‫ﻓﻴﻬﺎ ﻗﺺ ﻣﺒﺎﺷﺮ ﻣﻔﺮﺩ ﺃﻭ ﻣﺰﺩﻭﺝ ﺃﻭ ﺛﺎﻗﺐ ﺣﺴﺐ ﺍﻟﻐﺮﺽ ﺍﳌﻄﻠﻮﺏ ﻣﻦ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺫﻟﻚ ﻛﻤﺎ ﻳﺘـﻀﺢ‬ ‫ﺑﺎﻟﺸﻜﻞ )‪.(٥-٥‬‬

‫‪P‬‬

‫‪P‬‬ ‫‪Smooth@@Üßc‬‬

‫‪A‬‬

‫‪A‬‬ ‫’‪Rough@@å‬‬

‫‘‪—ÔÛa@óÏ@ŠØÛa@ÉĐÔß@ÝØ‬‬

‫‪P‬‬

‫‪P‬‬

‫‪Single Shear …ŠÐß@—Ó‬‬

‫‪Double Shear xë…Œß@—Ó‬‬

‫@@‬

‫‘‪@ @Š‘bj½a@—ÔÛa@pa‰bjna@HUMU@I@ÝØ‬‬

‫‪٩٧‬‬


‫ ﻛﻤﺎ ﻳﻼﺣﻆ ﺃﻥ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ ﻻ ﺗﻌﱪ ﻋﻦ ﺍﻟﻘﺺ ﺍﳋﺎﻟﺺ ﻟﻠﻤﻌﺪﻥ ﺍﳌﺨﺘـﱪ ﻷﻥ ﺍﻟﻘـﺺ‬‫ﺍﳌﺒﺎﺷﺮ ﻳﻌﺮﺽ ﺍﳌﻘﻄﻊ ﺇﱃ ﻗﺺ ﻣﺼﺤﻮﺏ ﺑﺈﳓﻨﺎﺀ ﺻﻐﲑ ﻭﻟﻴﺲ ﻗﺺ ﺧﺎﻟﺺ ﻛﻤﺎ ﺃﻥ ﺇﺟﻬﺎﺩ ﺍﻟﻘـﺺ‬ ‫ﺍﳌﺒﺎﺷﺮ ﺍﻓﺘﺮﺽ ﰱ ﺗﻌﻴﻴﻨﻪ ﺃﻥ ﻗﻮﺓ ﺍﻟﻘﺺ ﻣﻮﺯﻋﺔ ﺑﺎﻟﺘﺴﺎﻭﻱ ﻋﻠﻰ ﲨﻴﻊ ﻧﻘﻂ ﻣﻘﻄﻊ ﺍﳌﻌـﺪﻥ ﺍﳌﺨﺘـﱪ‬ ‫ﻭﻫﺬﺍ ﻟﻴﺲ ﺻﺤﻴﺤﹰﺎ ﲤﺎﻣﹰﺎ ﻭﻟﻜﻦ ﺑﻪ ﺷﺊ ﻣﻦ ﺍﻟﺘﻘﺮﻳﺐ‪ .‬ﻟﺬﻟﻚ ﻓﺈﻥ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﰱ ﺍﻟﻘﺺ ﻻ‬ ‫ﻳﺘﻢ ﺗﻌﻴﻨﻬﺎ ﻣﻦ ﺍﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ ﻭﺇﳕﺎ ﺗﻌﲔ ﻣﻦ ﺇﺧﺘﺒﺎﺭ ﺍﻻﻟﺘﻮﺍﺀ ﻷﻧﻪ ﻳﺴﺒﺐ ﻗﺺ ﺧﺎﻟﺺ‪.‬‬ ‫ ﻋﻨﺪﻣﺎ ﺗﺘﻌﺮﺽ ﻋﻴﻨﺔ ﻣﻦ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﺫﺍﺕ ﻣﻘﻄﻊ ﻣﺴﺘﺪﻳﺮ ﻣﺜﻼ ﻟﺘﺄﺛﲑ ﺍﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ ﺣﱴ ﺍﻟﻜﺴﺮ‬‫ﻓﺈﻥ ﻣﻘﻄﻊ ﺍﻟﻜﺴﺮ ﻳﻜﻮﻥ ﻧﺎﻋﻤﺎ ﰱ ﺟﺰﺀ ﻣﻨﻪ ﻭﻫﻮ ﺍﳉﺰﺀ ﺍﻟﺬﻯ ﺇﻧﺰﻟﻘﺖ ﻓﻴﻪ ﺍﳉﺰﻳﺌﺎﺕ ﻋﻠﻰ ﺑﻌـﻀﻬﺎ‬ ‫ﺍﻟﺒﻌﺾ ﻣﺴﺒﺒﺔ ﻧﻌﻮﻣﺔ ﺍﳌﻠﻤﺲ ﺑﺴﺒﺐ ﻗﻮﻯ ﺍﻟﻘﺺ‪ ،‬ﺃﻣﺎ ﺍﳉﺰﺀ ﺍﻵﺧﺮ ﻣﻦ ﺍﳌﻘﻄﻊ ﻓﻴﻜﻮﻥ ﺧﺸﻨﺎ ﻧﺘﻴﺠﺔ‬ ‫ﻋﺪﻡ ﲢﻤﻞ ﺫﻟﻚ ﺍﳉﺰﺀ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ ﻭﺣﺪﻭﺙ ﺍﻟﻜﺴﺮ ﻣﺒﺎﺷﺮﺓ ﲢﺖ ﻫﺬﺍ ﺍﳊﻤﻞ ﻭﺣﺪﻭﺙ ﺍﻧﻔﺼﺎﻝ‬ ‫ﺍﳉﺰﻳﺌﺎﺕ ﻭﻳﻜﻮﻥ ﺷﻜﻞ ﻣﻘﻄﻊ ﺍﻟﻜﺴﺮ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪.(٥-٥‬‬ ‫‪$% & 3-5‬ء‬

‫ﳛﺪﺙ ﻗﺺ ﺍﻻﳓﻨﺎﺀ ﺑﺎﻟﻜﻤﺮﺍﺕ ﺃﻭ ﺍﻟﻌﻨﺎﺻﺮ ﺍﻹﻧﺸﺎﺋﻴﺔ ﺍﻟﱴ ﻳﺆﺛﺮ ﻋﻠﻴﻬﺎ ﻗﻮﻯ ﻗﺺ ﺗﻜﻮﻥ ﻣﺼﺤﻮﺑﺔ ﺑﻌﺰﻭﻡ‬ ‫ﺍﳓﻨﺎﺀ‪ ،‬ﻟﺬﻟﻚ ﻓﺈﻧﻪ ﺇﺫﺍ ﲪﻠﺖ ﻛﻤﺮﺓ ﺑﺄﲪﺎﻝ ﺗﺴﺒﺐ ﻓﻴﻬﺎ ﺍﳓﻨﺎﺀ ﻓﺈﻥ ﺃﻯ ﻣﻘﻄﻊ ﻣﻦ ﻣﻘﺎﻃﻊ ﻫﺬﻩ ﺍﻟﻜﻤـﺮﺓ‬ ‫ﻳﻜﻮﻥ ﻣﻌﺮﺿﺎ ﻟﺘﺄﺛﲑ ﻋﺰﻡ ﺍﳓﻨﺎﺀ )‪ (M‬ﻭﻗﻮﻯ ﻗﺺ )‪ (Q‬ﻛﻤﺎ ﻳﺘﺒﲔ ﻣﻦ ﺍﻟﺸﻜﻞ )‪ ،(٦-٥‬ﻭﲢﺴﺐ ﻗﻴﻤﺔ‬ ‫ﺇﺟﻬﺎﺩﺍﺕ ﻗﺺ ﺍﻻﳓﻨﺎﺀ ﻋﻠﻰ ﻣﻘﺎﻃﻊ ﺍﻟﻜﻤﺮﺓ ﺍﶈﻤﻠﺔ ﻛﺎﻵﰐ‪:‬‬ ‫‪P‬‬ ‫'‪m‬‬

‫‪m‬‬

‫'‪m‬‬

‫‪m‬‬

‫'‪Q‬‬

‫‪Q‬‬

‫@ @ '‪M‬‬

‫‪M‬‬

‫‪SFD‬‬

‫‪BM‬‬

‫@@‬ ‫@@‬ ‫‘‪@ @òÜàa@ñŠàØÛa@Þì@óÜÇ@õbä−üa@âëŒÇë@—ÔÛa@ñìÓ@Éí‹ìm@HVMUI@ÝØ‬‬

‫‪٩٨‬‬


‫ﻧﻌﺘﱪ ﺍﳉﺰﺀ ﺍﶈﺼﻮﺭ ﺑﲔ ﺍﳌﻨﻄﻘﺘﲔ ﺍﳌﺴﺘﻌﺮﺿﺘﲔ ) ‪ (m' – m') ، (m – m‬ﻣﻦ ﺍﻟﻜﻤﺮﺓ ﺍﶈﻤﻠﺔ ﻭﺍﳌﺴﺎﻓﺔ ﺑﲔ‬ ‫ﺍﳌﻘﻄﻌﲔ )‪ ، (dx‬ﰒ ﺍﻟﻘﻄﻌﺔ ﺍﻟﻮﺍﻗﻌﺔ ﺃﻋﻠﻰ ﺍﳌﺴﺘﻮﻯ )`‪ (ss‬ﺍﳌﻮﺍﺯﻯ ﶈﻮﺭ ﺍﻟﺘﻌﺎﺩﻝ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿـﺢ ﺑﺎﻟـﺸﻜﻞ‬ ‫)‪.(٧-٥‬‬

‫@@‬ ‫‘‪@ @òÜàa@ñŠàØÛa@åß@õŒu@óÜÇ@ñŠqû½a@ôìÔÛa@HWMUI@ÝØ‬‬ ‫ﺣﻴﺚ ﺃﻥ‪:‬‬ ‫•‬

‫ﻋﺰﻡ ﺍﻻﳓﻨﺎﺀ ﻋﻨﺪ ﺍﳌﻘﻄﻊ ) ‪M = (m – m‬‬

‫•‬

‫ﻋﺰﻡ ﺍﻻﳓﻨﺎﺀ ﻋﻦ ﺍﳌﻘﻄﻊ ) '‪M + dM = M' = (m' – m‬‬

‫•‬

‫ﺍﻟﻘﻮﺓ ﺍﻟﻌﻤﻮﺩﻳﺔ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﻟﺴﻄﺢ ) ‪F = (m – s‬‬

‫•‬

‫ﺍﻟﻘﻮﺓ ﺍﻟﻌﻤﻮﺩﻳﺔ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﻟﺴﻄﺢ )`‪F + dF = F' = (m' – s‬‬

‫•‬

‫ﻋﺰﻡ ﺍﻟﻘﺼﻮﺭ ﺍﻟﺬﺍﺗﻰ ﻟﻘﻄﺎﻉ ﺍﻟﻜﻤﺮﺓ ﺍﶈﻤﻠﺔ = ‪I‬‬

‫•‬

‫‪ …bèug‬ﺍﻻﳓﻨﺎﺀ ﻋﻨﺪ ﺍﳌﻘﻄﻊ ) ‪σ = (m – m‬‬

‫•‬

‫‪ …bèug‬ﺍﻻﳓﻨﺎﺀ ﻋﻨﺪ ﺍﳌﻘﻄﻊ ) '‪σ + dσ = (m' – m‬‬

‫•‬

‫ﻣﺴﺎﺣﺔ ﺷﺮﳛﺔ ﻣﻦ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻋﻠﻰ ﺑﻌﺪ ﻣﺴﺎﻓﺔ )‪ (y‬ﻣﻦ ﳏﻮﺭ ﺍﻟﺘﻌﺎﺩﻝ = ‪da‬‬

‫‪ -‬ﺇﺟﻬﺎﺩ ﺍﻻﳓﻨﺎﺀ ﻋﻠﻰ ﺍﻟﺴﻄﺢ ) ‪ (m – s‬ﻫﻮ )‪(σ‬‬

‫‪M.y‬‬ ‫‪I‬‬

‫ ﺍﻟﻘﻮﺓ ﺍﻟﻌﻤﻮﺩﻳﺔ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﻟﺴﻄﺢ )‪ (m – s‬ﻫﻮ )‪(F‬‬‫‪. da‬‬

‫)‪(1‬‬

‫‪ -‬ﺇﺟﻬﺎﺩ ﺍﻻﳓﻨﺎﺀ ﻋﻠﻰ ﺍﻟﺴﻄﺢ )`‪ (m' – s‬ﻫﻮ )‪(σ + ∆ σ‬‬

‫‪M.y‬‬ ‫‪I‬‬

‫‪(M + dM) . y‬‬ ‫‪I‬‬

‫=‪σ‬‬

‫= ‪F = σ . da‬‬

‫=‪σ+∆σ‬‬

‫ ﺍﻟﻘﻮﺓ ﺍﻟﻌﻤﻮﺩﻳﺔ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﻟﺴﻄﺢ )`‪ (m' – s‬ﻫﻲ ) ‪(F + dF‬‬‫‪. da‬‬

‫)‪(2‬‬

‫‪(M + dM) . y‬‬ ‫‪I‬‬

‫‪٩٩‬‬

‫= ‪F + dF‬‬


‫ﻭﺣﻴﺚ ﺃﻥ )‪ (M + dM‬ﺃﻛﱪ ﻣﻦ )‪ ، (M‬ﻟﺬﻟﻚ ﻓﺈﻥ ﺍﻟﻘﻮﺓ ﺍﻟﻌﻤﻮﺩﻳﺔ )‪ (F + dF‬ﺗﻜﻮﻥ ﺃﻛـﱪ ﻣـﻦ )‪،(F‬‬ ‫ﻭﺣﻴﺚ ﺃﻥ ﺍﳉﺰﺀ ﺍﳌﻬﺸﺮ ﺑﺎﻟﺸﻜﻞ )‪ (٧-٥‬ﻭﺍﻟﻮﺍﻗﻊ ﺃﻋﻠﻰ ﺍﳌﺴﺘﻮﻯ )`‪ (ss‬ﰱ ﺣﺎﻟﺔ ﺍﺗﺰﺍﻥ‪ ،‬ﻟﺬﻟﻚ ﻓﺈﻥ ﻓـﺮﻕ‬ ‫ﺍﻟﻘﻮﺓ )‪ ، (F + dF‬ﻭﺍﻟﻘﻮﺓ )‪ (F‬ﻳﺴﺎﻭﻯ ﻭﻳﻌﺎﻛﺲ ﻗﻮﻯ ﻗﺺ ﻃﻮﻟﻴﺔ ﺗﺆﺛﺮ ﻋﻠﻰ ﺍﻟﺴﻄﺢ )`‪ (ss‬ﻭﺗﻜﻮﻥ ﻗﻴﻤـﺔ‬ ‫ﻗﻮﺓ ﺍﻟﻘﺺ ﺍﻟﻄﻮﻟﻴﺔ ﻟﻮﺣﺪﺓ ﺍﻟﻄﻮﻝ ﻣﻦ ﺍﳌﺴﺎﻓﺔ )‪.(dx‬‬ ‫ﻳﺘﻢ ﺍﻟﻮﺻﻮﻝ ﻟﻠﻔﺮﻕ ﺑﲔ ﺍﻟﻘﻮﺗﲔ ﻣﻦ ﺍﳌﻌﺎﺩﻟﺘﲔ )‪: (٢) ،(١‬‬ ‫)‪dF = ( F + dF) – (F‬‬ ‫‪.da‬‬

‫‪M.y‬‬

‫‪. da -‬‬

‫‪(M + dM) . y‬‬

‫‪I‬‬

‫= ‪dF‬‬

‫‪I‬‬

‫)‪(3‬‬

‫‪dM . y‬‬

‫‪.da‬‬

‫‪I‬‬

‫ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﻋﻨﺪ ﺍﳌﺴﺘﻮﻯ )`‪ (s – s‬ﻳﺘﻌﲔ ﻛﻤﺎ ﻳﻠﻰ‪:‬‬

‫‪dF‬‬ ‫‪dx .b‬‬

‫)‪(4‬‬

‫= ‪dF‬‬

‫=‪q‬‬

‫‪dF = q. b. dx‬‬

‫ﻟﻺﺗﺰﺍﻥ ﻓﺈﻥ ﺍﳌﻌﺎﺩﻟﺔ )‪ = (٣‬ﺍﳌﻌﺎﺩﻟﺔ )‪(٤‬‬ ‫‪dM . y . da = q. b. dx‬‬ ‫‪I‬‬ ‫‪dM . y. da‬‬ ‫=‪q‬‬ ‫‪I. b. dx‬‬ ‫‪1‬‬ ‫‪dM‬‬ ‫=‪q‬‬ ‫‪.‬‬ ‫)‪. ( da.y‬‬ ‫‪I.b‬‬ ‫‪dx‬‬

‫ﺣﻴﺚ ﺃﻥ‪:‬‬

‫‪da. y = S‬‬

‫‪,‬‬

‫‪=Q‬‬

‫‪dM‬‬ ‫‪dx‬‬

‫‪Q.S‬‬ ‫‪I. b‬‬

‫ﺣﻴﺚ‪:‬‬ ‫ ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﰱ ﺍﻻﳓﻨﺎﺀ ﻋﻨﺪ ﺍﳌﺴﺘﻮﻯ ﺍﳌﻄﻠﻮﺏ ﻷﻯ ﻗﻄﺎﻉ =‬‫‪ -‬ﻗﻮﺓ ﺍﻟﻘﺺ ﺍﳌﺆﺛﺮﺓ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ =‬

‫‪q‬‬

‫‪Q‬‬

‫ ﺍﻟﻌﺰﻡ ﺍﻷﻭﻝ ﻟﻠﻤﺴﺎﻓﺔ ﺣﻮﻝ ﳏﻮﺭ ﺍﻟﺘﻌﺎﺩﻝ ﳉﺰﺀ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﻜﻤﺮﺓ ﺍﻟﺬﻯ ﻳﻘﻊ ﺃﻋﻠﻰ‬‫ﺍﳌﺴﺘﻮﻯ ﺍﳌﻄﻠﻮﺏ ﺣﺴﺎﺏ ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﻋﻨﺪﻩ =‬

‫‪S‬‬

‫‪ -‬ﻋﺰﻡ ﺍﻟﻘﺼﻮﺭ ﺍﻟﺬﺍﺗﻰ ﳌﻘﻄﻊ ﺍﻟﻜﻤﺮﺓ ﺍﳌﺴﺘﻌﺮﺽ =‬

‫‪I‬‬

‫‪ -‬ﻋﺮﺽ ﺍﻟﻘﻄﺎﻉ ﻋﻨﺪ ﺍﳌﺴﺘﻮﻯ ﺍﳌﻄﻠﻮﺏ =‬

‫‪b‬‬

‫‪١٠٠‬‬

‫=‪q‬‬


‫ﻭﻳﻼﺣﻆ ﻣﻦ ﻫﺬﻩ ﺍﳌﻌﺎﺩﻟﺔ ﺃﻥ ﻗﻴﻤﺔ )‪ (b) ، (S‬ﺗﺘﻐﲑ ﺑﺎﺧﺘﻼﻑ ﺍﳌﻮﺿﻊ ﺍﳌﻄﻠﻮﺏ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ‬ ‫ﺃﻣﺎ ﻗﻴﻤﺔ )‪ (I) ، (Q‬ﻓﻬﻰ ﺛﺎﺑﺘﺔ ﻟﻜﻞ ﻧﻘﻂ ﺍﳌﻘﻄﻊ‪ .‬ﻭﳝﻜﻦ ﺗﻄﺒﻴﻖ ﻫﺬﻩ ﺍﳌﻌﺎﺩﻟﺔ ﰱ ﺣﺎﻟﱴ ﺗﺄﺛﲑ ﻗﻮﻯ ﺍﻟﻘﺺ‬ ‫ﺇﺫﺍ ﻛﺎﻧﺖ ﰱ ﺍﲡﺎﻩ ﺭﺃﺳﻰ )‪ (Qy‬ﺃﻭ ﺍﲡﺎﻩ ﺃﻓﻘﻰ )‪ (Qx‬ﺑﺎﻟﻨﺴﺒﺔ ﳌﻘﻄﻊ ﺍﻟﻜﻤﺮﺓ ﺍﳌﺴﺘﻌﺮﺽ‪ .‬ﻭﻣﻦ ﻫﻨﺎ ﻓـﺈﻥ‬ ‫ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﰱ ﺍﻻﳓﻨﺎﺀ ﻳﺘﻤﺎﺷﻰ ﻣﻊ ﺍﻟﻘﻮﺓ ﺍﳌﺆﺛﺮﺓ ﰱ ﺍﻟﻘﺺ ﻛﻤﺎ ﻳﻠﻰ‪:‬‬ ‫‪Qx. S@yy‬‬ ‫‪Iy. b//yy‬‬

‫‪Qy. S@xx‬‬ ‫‪Ix. b//xx‬‬

‫= ‪* qy‬‬

‫= ‪* qx‬‬

‫ﻭﻳﻼﺣﻆ ﺃﻥ ﺍﻟﻘﺺ ﺍﻟﻨﺎﺗﺞ ﻣﻦ ﺍﻷﲪﺎﻝ ﺍﳌﺴﺒﺒﺔ ﻟﻼﳓﻨﺎﺀ ﻳﻮﻟﺪ ﺇﺟﻬﺎﺩﺍﺕ ﺿﻠﻌﻴﺔ ﻗﻄﺮﻳﺔ ﺑﺎﻟﻜﻤﺮﺍﺕ ﻭﻫـﻰ‬ ‫ﻋﺒﺎﺭﺓ ﻋﻦ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﺮﺋﻴﺴﻴﺔ ﻭﻗﺪ ﺗﻜﻮﻥ ﺇﺟﻬﺎﺩ ﺷﺪ ﺃﻭ ﺇﺟﻬﺎﺩ ﺿﻐﻂ ﻛﻤﺎ ﻳﺘﻀﺢ ﻣﻦ ﺍﻟـﺸﻜﻞ )‪.(٨-٥‬‬ ‫ﻭﺗﻜﻮﻥ ﺗﻠﻚ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺑﻘﻴﻤﺔ ﻋﻈﻤﻰ ﺗﺴﺎﻭﻯ ﻗﻴﻤﺔ ﻗﺺ ﺍﻻﳓﻨﺎﺀ )‪ (q‬ﻟـﻨﻘﻂ ﺍﳌﻘـﺎﻃﻊ ﺍﳌـﺴﺘﻌﺮﺿﺔ‬ ‫ﺍﻟﻮﺍﻗﻌﺔ ﻋﻨﺪ ﺧﻂ ﺍﻟﺘﻌﺎﺩﻝ‪ .‬ﻭﺗﻜﱪ ﻗﻴﻤﺔ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﻀﻠﻌﻴﺔ ﺍﻟﻘﻄﺮﻳﺔ ﻛﻠﻤﺎ ﺯﺍﺩﺕ ﻗﻴﻤﺔ )‪ (q‬ﺃﻯ ﻛﻠﻤـﺎ‬ ‫ﺍﻗﺘﺮﺑﻨﺎ ﻣﻦ ﻧﻘﻂ ﺍﻻﺭﺗﻜﺎﺯ ﻟﻠﻜﻤﺮﺓ‪.‬‬

‫‘‪@ @õbä−üa@—Ó@åß@òîÈÜ™@pa…b;;èug@HXMUI@ÝØ‬‬

‫‪١٠١‬‬


‫ﻭﳝﻜﻦ ﺗﻌﻴﲔ ﺗﻮﺯﻳﻊ ﺇﺟﻬﺎﺩ ﻗﺺ ﺍﻻﳓﻨﺎﺀ ﻋﻠﻰ ﺑﻌﺾ ﻣﻘﺎﻃﻊ ﺍﻟﻜﻤﺮﺍﺕ ﺍﶈﺪﺩﺓ ﺍﻟﺸﻜﻞ ﻛﻤﺎ ﻳﻠﻰ‪:‬‬ ‫‪@ @ÉiŠß@ëc@ÝîĐnß@ÊbĐÓ MQ‬‬ ‫@@‬ ‫‪b‬‬ ‫‪d/2-y‬‬

‫‪qst‬‬

‫‪y‬‬

‫‪qmax = 1.5 Q/A‬‬ ‫‪A=bd‬‬

‫‪d/2 t‬‬

‫‪s‬‬

‫‪d‬‬

‫‪Qy‬‬

‫‘‪@ @@@ñŠàØÛ@ÝîĐnß@ÉĐÔß@óÜÇ@õbä−üa@—Ó@…bèug@Éí‹ìm@HYMUI@ÝØ‬‬

‫ﻗﻴﻤﺔ ﺇﺟﻬﺎﺩ ﻗﺺ ﺍﻻﳓﻨﺎﺀ ﻋﻨﺪ ﺃﻯ ﺟﺰﺀ )‪ (st‬ﻟﻠﻤﻘﻄﻊ ﺍﳌﺴﺘﻄﻴﻞ ﲢﺖ ﺗﺄﺛﲑ ﻗﻮﺓ ﺍﻟﻘﺺ )‪:(Qy‬‬ ‫‪Qy. S@xx‬‬ ‫‪Ix. b//xx‬‬ ‫)‬

‫‪4y2‬‬ ‫‪d2‬‬

‫‪( 1-‬‬

‫‪bd2‬‬

‫= ] )‪- y‬‬

‫‪8‬‬

‫‪d‬‬ ‫‪2‬‬

‫(‬

‫‪1‬‬ ‫‪2‬‬

‫‪d‬‬

‫‪– y). b. [ y +‬‬

‫‪2‬‬ ‫‪b.d3‬‬ ‫‪12‬‬

‫)‬

‫‪4y2‬‬ ‫‪d2‬‬

‫‪. (1-‬‬

‫‪Q‬‬ ‫‪A‬‬

‫‪.‬‬

‫‪3‬‬ ‫‪2‬‬

‫= )‬

‫‪4y2‬‬ ‫‪d2‬‬

‫‪(1 -‬‬

‫‪Q‬‬ ‫‪b.d‬‬

‫‪.‬‬

‫‪3‬‬ ‫‪2‬‬

‫=‪q‬‬

‫( =‪S‬‬

‫= ‪IX‬‬ ‫=‪q‬‬

‫ﺣﻴﺚ ﺃﻥ )‪ (A‬ﻫﻰ ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ‪.‬‬ ‫ﻭﻫﻨﺎ ﺗﺘﻌﲔ ﻗﻴﻤﺔ ﺇﺟﻬﺎﺩ ﻗﺺ ﺍﻻﳓﻨﺎﺀ ﳌﻘﻄﻊ ﻣﺴﺘﻄﻴﻞ ﻋﻨﺪ ﺃﻯ ﺟﺰﺀ ﻣﻦ ﻫﺬﺍ ﺍﳌﻘﻄﻊ ﻭﺍﻟﱵ ﲤﺜـﻞ ﻗﻄـﻊ‬ ‫ﻣﻜﺎﻓﺊ ﺣﻴﺚ ﻳﻜﻮﻥ ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﻋﻨﺪ ‪‬ﺎﻳﱵ ﺍﳌﻘﻄﻊ ﻳﺴﺎﻭﻯ ﺻﻔﺮ ﻹﻧﻌﺪﺍﻡ ﻗﻴﻤﺔ )‪ (S‬ﻛﻤﺎ ﻫـﻮ ﻣـﺒﲔ‬ ‫ﺑﺎﻟﺸﻜﻞ )‪ ،(٩-٥‬ﻭﻳﻜﻮﻥ ﺃﻗﺼﻰ ﺇﺟﻬﺎﺩ ﻗﺺ ﻋﻨﺪ ﻣﻨﺘﺼﻒ ﺍﻟﻘﻄﺎﻉ ﻭﻗﻴﻤﺘﻪ‪:‬‬ ‫‪3‬‬ ‫‪Q‬‬ ‫‪.‬‬ ‫‪2‬‬ ‫‪A‬‬

‫‪١٠٢‬‬

‫= ‪qmax‬‬


‫@@‬ ‫‪@ @@ÝØ’Ûa@ðŠöa…@ÊbĐÓ@MR‬‬

‫‪qst‬‬ ‫)‪Qmax= 4/3 (Q/A‬‬

‫‪R‬‬

‫‪t‬‬

‫‪y‬‬

‫‪S‬‬ ‫‪θ‬‬

‫‪R‬‬

‫‪Q‬‬ ‫‘‪@ @@Ší†nß@ÉĐÔß@óÜÇ@—ÔÛa@…bèug@Éí‹ìm@HQPMUI@ÝØ‬‬

‫ﻗﻴﻤﺔ ﺇﺟﻬﺎﺩ ﻗﺺ ﺍﻻﳓﻨﺎﺀ ﻋﻨﺪ ﺃﻯ ﺟﺰﺀ ‪ st‬ﻣﻦ ﺍﻟﻘﻄﺎﻉ ﺍﻟﺪﺍﺋﺮﻱ ﲢﺖ ﺗﺄﺛﲑ ﻗﻮﺓ ﺍﻟﻘﺺ ‪ Q‬ﻛﻤـﺎ ﻫـﻮ‬ ‫ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪:(١٠-٥‬‬ ‫)‬

‫‪y2‬‬ ‫‪R2‬‬

‫‪) . (1-‬‬

‫‪Q‬‬ ‫‪π R2‬‬

‫‪.‬‬

‫‪4‬‬ ‫‪3‬‬

‫(=‪q‬‬

‫ﻭﲤﺜﻞ ﻫﺬﻩ ﺍﳌﻌﺎﺩﻟﺔ ﺃﻳﻀﺎ ﻗﻄﻊ ﻣﻜﺎﻓﺊ ﺭﺃﺳﻪ ﻋﻨﺪ ﺧﻂ ﺍﻟﺘﻌﺎﺩﻝ ﻭ‪‬ﺎﻳﺘﻪ ﻋﻨﺪ ‪‬ﺎﻳﱴ ﺍﳌﻘﻄﻊ ﻭﺗﻜﻮﻥ ﻗﻴﻤـﺔ‬ ‫ﺍﻹﺟﻬﺎﺩ ﺍﻷﻓﻘﻰ‪.‬‬

‫‪4‬‬ ‫‪Q‬‬ ‫‪= 3 .‬‬ ‫‪A‬‬

‫@@‬ ‫@@‬ ‫@@‬ ‫@@‬ ‫@@‬ ‫@@‬ ‫@@‬ ‫@@‬

‫‪١٠٣‬‬

‫‪Q‬‬ ‫‪π‬‬

‫‪.‬‬

‫‪4‬‬ ‫=‬ ‫‪3‬‬

‫‪qmax‬‬


@@ @ @I@ÒŠy@ÝØ‘@óÜÇ@ÊbĐÓ@MS @@ q 2-2

b

tf

q 1-1

1 1 2 -2 -2 2

d

3 t2

q -2-2q 3-3 = q max

3

tf

@@ @ @I@ÒŠy@ÝØ‘@óÜÇ@ÊbĐÓ@óÜÇ@õbä−üa@—Ó@pa…bèug@Éí‹ìm@HQQMUI@ÝØ‘

:‫ﻳﺘﻢ ﺗﻌﻴﲔ ﻗﻴﻢ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﺺ ﻣﻦ ﺍﻟﻌﻼﻗﺔ ﺍﻵﺗﻴﺔ ﻋﻨﺪ ﺍﳌﺴﺘﻮﻳﺎﺕ ﺍﳌﺨﺘﻠﻔﺔ ﰱ ﺍﻟﻌﺮﺽ‬

q=

Qy. S@xx Ix. b//xx

q1-1 = 0.0 Q

( tf . b. d - tf ) Ix . b 2 Q d-tf q2'-2' = (tf.b. ) = q2-2 . Ix.t2 2

q2-2 =

q3-3 =

Q Ix.t2

[t1.b.

d-tf 2

q3-3 = qmax = q2'-2' +

Q Ix.t2

+( [(

d

b

- tf). t2. (

2 d 2

q2'-2' > q2-2

t2

- t1).t2. (

d 2

-tf)/2]

d 2

- t1)/2]

(١١-٥) ‫ﻭﻳﻜﻮﻥ ﺗﻮﺯﻳﻊ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﺺ ﰱ ﺍﻻﳓﻨﺎﺀ ﻛﻤﺎ ﻫﻮ ﻣﺒﲔ ﺑﺎﻟﺸﻜﻞ‬

١٠٤


‫‪@ @T@ÒŠy@ÝØ‘@óÜÇ@ÊbĐÓ@MT‬‬

‫‘‪@ @T@ÒŠy@ÝØ‘@óÜÇ@ÊbĐÓ@óÜÇ@õbä−üa@óÏ@—ÔÛa@pa…bèug@Éí‹ìm@HQRMUI@ÝØ‬‬

‫ﻳﻜﻮﻥ ﺗﻮﺯﻳﻊ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﺺ ﰱ ﺍﻻﳓﻨﺎﺀ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﺑﺘﻄﺒﻴﻖ ﺍﻟﻘﺎﻧﻮﻥ‪:‬‬

‫‪Qy. S@xx‬‬ ‫‪Ix. b//xx‬‬

‫=‪q‬‬

‫ﻭﺫﻟﻚ ﻟﻜﻞ ﺍﻟﻨﻘﻂ ﺍﻟﺮﺋﻴﺴﻴﺔ ﺍﻟﱴ ﳛﺪﺙ ‪‬ﺎ ﺗﻐﻴﲑ ﻭﻫﻰ ‪ 5 ، 4 ، 3 ، 2 ، 1‬ﻛﻤﺎ ﻳﻠﻲ‪:‬‬ ‫‪q1 = 0.0‬‬

‫) ‪. (b. t1.y1‬‬ ‫‪b‬‬

‫‪q3 > q2‬‬

‫‪) = qmax‬‬

‫‪y12.t2‬‬ ‫‪2‬‬

‫(‬

‫‪= q2.‬‬

‫‪t2‬‬ ‫‪Q‬‬ ‫‪Ix.t2‬‬

‫‪] = q3 +‬‬

‫‪y1‬‬ ‫‪2‬‬

‫) ‪. (b. t1.y1‬‬

‫‪[ b. t1.y1 + y1.t2.‬‬

‫‪Q‬‬ ‫‪Ix . b‬‬ ‫‪Q‬‬ ‫‪Ix.t2‬‬ ‫‪Q‬‬ ‫‪Ix.t2‬‬

‫= ‪q2‬‬

‫= ‪q3‬‬

‫= ‪q4‬‬

‫‪q5 = 0.0‬‬

‫ﻭﺗﻮﺯﻉ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﺺ ﺍﶈﺴﻮﺑﺔ ﻋﻠﻰ ﻛﺎﻣﻞ ﺍﻟﻘﻄﺎﻉ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪.(١٢-٥‬‬ ‫‪١٠٥‬‬


‫‪@ @õbä−üa@—Ó@‰bjng‬‬ ‫ﳚﺮﻯ ﺇﺧﺘﺒﺎﺭ ﻗﺺ ﺍﻻﳓﻨﺎﺀ ﻛﺈﺧﺘﺒﺎﺭ ﻗﺒﻮﻝ ﺗﻨﺺ ﻋﻠﻴﻪ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻟﻠﻤﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﻣﺜﻞ ﺍﳊﺪﻳـﺪ‬ ‫ﺍﻟﺰﻫﺮ ﻭﺍﳋﺮﺳﺎﻧﺔ ﻭﺍﳋﺸﺐ‪ ،‬ﻭﻻ ﳚﺮﻯ ﺇﺧﺘﺒﺎﺭ ﻗﺺ ﺍﻻﳓﻨﺎﺀ ﳌﻌﺮﻓﺔ ﻣﻘﺎﻭﻣﺔ ﺍﳌـﻮﺍﺩ ﻟﻘـﺺ ﺍﻻﳓﻨـﺎﺀ‪،‬‬ ‫ﻭﺗﺘﻌﺮﺽ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﰱ ﺍﻻﳓﻨﺎﺀ ﺿﻤﻨﺎ ﺇﱃ ﻗﺺ ﺍﻻﳓﻨﺎﺀ ﻭﻟﻜﻦ ﺍﻟﻘﻮﻯ ﺍﻟﱴ ﺗﺴﺒﺐ ﻛﺴﺮ ﺍﻟﻌﻴﻨﺔ ﻫـﻰ‬ ‫ﻗﻮﻯ ﺍﻟﺸﺪ ﻭﻣﻨﻬﺎ ﺗﺘﻌﻴﲔ ﻣﻘﺎﻭﻣﺔ ﺍﻻﳓﻨﺎﺀ ﲝﺴﺎﺏ ﻣﻌﺎﻳﺮ ﺍﻟﻜﺴﺮ‪ .‬ﻭﻻ ﺗﻨﻜﺴﺮ ﺍﻟﻜﻤﺮﺍﺕ ﺍﳌﺨﺘـﱪﺓ ﻣـﻦ‬ ‫ﻫﺬﻩ ﺍﳌﻮﺍﺩ ﺑﺘﺄﺛﲑ ﻗﺺ ﺍﻻﳓﻨﺎﺀ ﺇﻻ ﺇﺫﺍ ﻛﺎﻥ ﻋﻤﻖ ﺍﻟﻜﻤﺮﺓ ﺍﳌﺨﺘﱪﺓ ﻛﺒﲑﹰﺍ ﻣﻊ ﺻﻐﺮ ﲝﺮ ﺍﻟﻜﻤـﺮﺓ ﻧـﺴﺒﻴﺎ‬ ‫ﻭﻗﺪ ﻳﻜﻮﻥ ﺍﻟﻜﺴﺮ ﺑﺴﺒﺐ ﺇﺟﻬﺎﺩ ﺍﻟﺸﺪ ﺍﻟﻘﻄﺮﻱ ﻛﻤﺎ ﰱ ﺍﻟﻜﻤﺮﺍﺕ ﺍﳋﺮﺳﺎﻧﻴﺔ‪ ،‬ﺃﻭ ﺑﺴﺒﺐ ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ‬ ‫ﺍﻷﻓﻘﻰ ﻛﻤﺎ ﰱ ﺍﻟﻜﻤﺮﺍﺕ ﺍﳋﺸﺒﻴﺔ ﻭﻳﻈﻬﺮ ﺫﻟﻚ ﺑﺎﻟﺸﻜﻞ )‪.(١٣-٥‬‬ ‫‪P‬‬

‫‪P‬‬ ‫’‪k‬‬

‫‪òãbŠ‬‬

‫‪—Ó‬‬

‫‘†@‪ðŠĐÓ‬‬

‫‘‪@õbä−üa@—Ó@pa…bèug@åß@òÐ–ÔÛa@paŠàØÛa@óÏ@ŠØÛa@HQSMUI@ÝØ‬‬

‫‪ & 4-5‬ء‬

‫ﺍﻻﻟﺘﻮﺍﺀ ﻫﻮ ﺇﻧﺰﻻﻕ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﺠﺴﻢ ﻋﻠﻰ ﺍﳌﻘﻄﻊ ﺍﻟﺬﻱ ﳚﺎﻭﺭﻩ ﺣﻮﻝ ﳏﻮﺭ ﻃـﻮﱄ ﻋﻤـﻮﺩﻱ‬ ‫ﻋﻠﻰ ﻛﻞ ﻣﻦ ﺍﳌﻘﻄﻌﲔ ﻭﻟﻴﺲ ﺇﻧﺰﻻﻕ ﺍﳌﻘﻄﻌﲔ ﻋﻦ ﺑﻌﻀﻬﻤﺎ ﰱ ﺍﲡﺎﻩ ﺭﺃﺳﻰ ﺃﻭ ﺍﲡﺎﻩ ﺃﻓﻘﻰ ﻛﻤﺎ ﰱ ﺣﺎﻟـﺔ‬ ‫ﺍﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ‪ ،‬ﻭﻟﻜﻦ ‪ .Š@ ;Ła@ÉĐÔ½a@óÜÇ@ê‰ìª@Þìy@´ÈĐÔ½a@†yc@æa‰ë†i@ÖüŒãg‬ﻭﳛﺪﺙ ﺍﻻﻟﺘـﻮﺍﺀ ﺇﺫﺍ‬ ‫ﺗﻌﺮﺽ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﺇﱃ ﻋﺰﻡ ﺍﻟﺘﻮﺍﺀ )‪ (T‬ﻳﻌﻤﻞ ﰱ ﻣﺴﺘﻮﻯ ﺍﻟﻘﻄﺎﻉ ﺃﻭ ﻣﻮﺍﺯﻯ ﳌﺴﺘﻮﻯ ﺍﻟﻘﻄـﺎﻉ‬ ‫ﻭﻳﻜﻮﻥ ﺩﻭﺭﺍﻥ ﻫﺬﺍ ﺍﻟﻌﺰﻡ ﺣﻮﻝ ﺍﶈﻮﺭ ﺍﻟﻄﻮﱃ ﻟﻠﻌﻨﺼﺮ ﺍﻻﻧﺸﺎﺋﻰ‪ .‬ﻭﳛﺪﺩ ﺍﻻﻟﺘﻮﺍﺀ ﰱ ﺃﺟﺰﺍﺀ ﺍﳌﻨـﺸﺂﺕ‬ ‫ﻭﺍﳌﺎﻛﻴﻨﺎﺕ ﺍﳌﺨﺘﻠﻔﺔ ﻣﺜﻞ ﺃﻋﻤﺪﺓ ﺇﺩﺍﺭﺓ ﺍﳌﻮﺗﻮﺭ ﻭﻋﻤﻮﺩ ﺍﳌﺮﻭﺣﺔ ﻟﻠﻄﺎﺋﺮﺍﺕ… ﺇﱁ‪.‬‬

‫‪١٠٦‬‬


‫ﻭﻳﻮﺟﺪ ﺣﺎﻻﺕ ﳐﺘﻠﻔﺔ ﻟﻌﺰﻭﻡ ﺍﻹﻟﺘﻮﺍﺀ ﻭﻣﻨﻬﺎ‪:‬‬ ‫‪ -١‬ﻋﺰﻡ ﺍﻟﺘﻮﺍﺀ )‪ (T‬ﻳﺆﺛﺮ ﻋﻠﻰ ﺍﻟﻄﺮﻑ ﺍﳊﺮ ﻟﻘﻀﻴﺐ ﺣﺮ ﻣﻦ ﺃﺣﺪ ﺃﻃﺮﺍﻓﻪ ﻭﻣﺜﺒﺖ ﻣﻦ ﺍﻟﻄﺮﻑ ﺍﻵﺧﺮ‬ ‫ﺃﻯ ﻋﻠﻰ ﺷﻜﻞ ﻛﺎﺑﻮﱄ‪.‬‬ ‫‪ -٢‬ﺗﺄﺛﲑ ﻋﺰﻣﻰ ﺇﻟﺘﻮﺍﺀ ﻏﲑ ﻣﺘﺴﺎﻭﻳﲔ ﰱ ﺍﳌﻘﺪﺍﺭ ﻭﳍﺎ ﻧﻔﺲ ﺍﲡﺎﻩ ﺍﻟﺪﻭﺭﺍﻥ ﺍﻟﻌﺰﻡ ﺍﻷﻭﻝ )‪ (T1‬ﻭﺍﻟﻌـﺰﻡ‬ ‫ﺍﻟﺜﺎﱏ )‪ (T2‬ﻓﺈﺫﺍ ﻛﺎﻥ ‪.T2 < T1‬‬ ‫ﻓﺈﻥ ﻗﻴﻤﺔ ﻋﺰﻡ ﺍﻹﻟﺘﻮﺍﺀ ﺍﳌﺆﺛﺮﺓ ﺍﳋﺎﻟﺼﺔ )‪(T‬‬ ‫‪T = T1 – T2‬‬

‫‪ -٣‬ﻭﺟﻮﺩ ﻋﺰﻣﻲ ﺇﻟﺘﻮﺍﺀ ﻣﺘﺴﺎﻭﻳﲔ ﰱ ﺍﳌﻘﺪﺍﺭ ﺃﺣﺪﳘﺎ ﻋﻜﺲ ﺍﻵﺧﺮ ﰱ ﺍﲡﺎﻩ ﺍﻟﺘﺄﺛﲑ‪.‬‬ ‫‪ -٤‬ﺗﻌﺮﺽ ﺍﻟﻌﻴﻨﺔ ﺇﱃ ﻗﻮﺗﲔ ﻣﺘﻮﺍﺯﻳﺘﲔ ﻭﻣﺘﻌﺎﻛﺴﺘﲔ ﰱ ﺍﻻﲡﺎﻩ ﻭﻣﺘﺴﺎﻭﻳﺘﲔ ﰱ ﺍﳌﻘـﺪﺍﺭ )‪ (Q‬ﻭﺗﺒﻌـﺪ‬ ‫ﺇﺣﺪﺍﳘﺎ ﻋﻠﻰ ﺍﻷﺧﺮﻯ ﻣﺴﺎﻓﺔ )‪ (e‬ﲝﻴﺚ ﺗﻘﻊ ﻛﻞ ﻣﻦ ﺍﻟﻘﻮﺗﲔ ﰱ ﻧﻔﺲ ﻣﺴﺘﻮﻯ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ‬ ‫ﻭﺑﺬﻟﻚ ﺗﺴﺒﺒﺎﻥ ﻋﺰﻡ ﺍﻟﺘﻮﺍﺀ ﻗﻴﻤﺘﻪ )‪.(T‬‬ ‫‪T = Q.e‬‬

‫‪ -٥‬ﺗﺄﺛﲑ ﻗﻮﺓ ﻻﻣﺮﻛﺰﻳﺔ )‪ (Q‬ﻋﻠﻰ ﻣﺴﺘﻮﻯ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﻌﻴﻨﺔ ﻭﺗﺒﻌﺪ ﻋﻠﻰ ﻣﺮﻛﺰ ﺍﳌﻘﻄﻊ ﻣﺴﺎﻓﺔ‬ ‫)‪ (e‬ﻓﺈ‪‬ﺎ ﺗﺴﺒﺐ ﻋﺰﻡ ﺍﻟﺘﻮﺍﺀ )‪.(T‬‬ ‫‪T = Q.e‬‬

‫‪@ @òÐÜn‚½a@pbÇbĐÔÛa@pa‡@pbäîÈÜÛ@õaìnÛüa@—Ó@@QMTMU‬‬ ‫@@ @‬ ‫‪@ @oà–ß@ôŠöa…@ÊbĐÓ@MQ‬‬ ‫ﳚﺐ ﺃﻥ ﻧﻀﻊ ﰱ ﺍﻻﻋﺘﺒﺎﺭ ﺑﻌﺾ ﺍﻟﻔﺮﻭﺽ ﺍﻟﻨﻈﺮﻳﺔ ﻟﺘﻌﻴﲔ ﺟﻬﺪ ﺍﻟﻘﺺ ﺍﻟﻨﺎﺷﻰﺀ ﻋﻦ ﻋﺰﻡ ﺍﻟﺘـﻮﺍﺀ ﻋﻠـﻰ‬ ‫ﻗﻀﻴﺐ ﻣﻌﺪﱏ ﻣﺴﺘﺪﻳﺮ ﺍﳌﻘﻄﻊ ﻭﺗﻠﻚ ﺍﻟﻔﺮﻭﺽ ﻛﻤﺎ ﻳﻠﻰ‪:‬‬ ‫‪ -١‬ﺃﻥ ﺗﻜﻮﻥ ﻣﺎﺩﺓ ﺍﻟﻘﻀﻴﺐ ﺍﳌﺨﺘﱪ ﻣﺘﺠﺎﻧﺴﺔ ﲤﺎﻣﹰﺎ‪.‬‬ ‫‪ -٢‬ﺃﻥ ﻳﻜﻮﻥ ﺍﻟﻠﻰ ﻣﻨﺘﻈﻢ ﻋﻠﻰ ﻃﻮﻝ ﺍﻟﻘﻀﻴﺐ ﺍﳌﺨﺘﱪ‪.‬‬ ‫‪ -٣‬ﺃﻥ ﻳﻜﻮﻥ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﻘﻀﻴﺐ ﻣﺴﺘﻮﻯ ﻭﺩﺍﺋﺮﻯ ﺍﻟﺸﻜﻞ ﻗﺒﻞ ﺍﻟﺘﺄﺛﲑ ﺑﻌﺰﻡ ﺍﻹﻟﺘﻮﺍﺀ ﻭﻛﺬﻟﻚ‬ ‫ﻳﻜﻮﻥ ﺃﻳﻀﺎ ﻣﺴﺘﻮﻯ ﻭﺩﺍﺋﺮﻯ ﺑﻌﺪ ﺍﻟﺘﺄﺛﲑ ﺑﺎﻟﻌﺰﻡ‪.‬‬ ‫‪ -٤‬ﺃﻥ ﻳﻜﻮﻥ ﻗﻄﺮ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﺍﻟﺪﺍﺋﺮﻯ ﺧﻂ ﻣﺴﺘﻘﻴﻢ ﻗﺒﻞ ﻭﺑﻌﺪ ﺍﻟﺘﺄﺛﲑ ﺑﻌﺰﻡ ﺍﻹﻟﺘﻮﺍﺀ‪.‬‬ ‫‪١٠٧‬‬


‫‘‪@ @@Ší†n½a@ÉĐÔ½a@óÜÇ@õaìnÛ⁄a@—Ó@pa…bèug@Éí‹ìm@HQTMUI@ÝØ‬‬

‫ﺇﺫﺍ ﺃﺧﺬﻧﺎ ﻗﻀﻴﺐ ﻣﺴﺘﺪﻳﺮ ﺍﳌﻘﻄﻊ ﺣﺮ ﻣﻦ ﺃﺣﺪ ﺃﻃﺮﺍﻓﻪ ﻳﺆﺛﺮ ﻋﻠﻴﻪ ﻋﺰﻡ ﺇﻟﺘﻮﺍﺀ )‪ (T‬ﻭﻣﺜﺒﺖ ﻣﻦ ﺍﻟﻄﺮﻑ‬ ‫ﺍﻵﺧﺮ ﻟﻜﻰ ﻳﺴﻬﻞ ﺗﺄﺛﲑ ﻋﺰﻡ ﺍﻻﻟﺘﻮﺍﺀ ﻟﻜﻰ ﳛﺪﺙ ﱄ ﺑﺎﻟﻘﻀﻴﺐ‪ .‬ﻓﺈﺫﺍ ﺭﺳﻢ ﺧﻂ ﻣﺴﺘﻘﻴﻢ )‪ (ab‬ﻋﻠـﻰ‬ ‫ﺍﻟﺴﻄﺢ ﺍﳋﺎﺭﺟﻰ ﻟﻠﻘﻀﻴﺐ ﺣﻴﺚ ﺃﻥ ﻫﺬﺍ ﺍﳋﻂ ﳝﺜﻞ ﻃﻮﻝ ﺍﻟﻘﻀﻴﺐ ﺍﳌﺨﺘﱪ ﻛﻠﻪ‪ ،‬ﻓﺈﻥ ﻫﺬﺍ ﺍﳋﻂ ﻳﺘﻐﲑ‬ ‫ﻭﺿﻌﻪ ﺇﱃ ﻭﺿﻊ ﺃﺧﺮ ﻭﻫﻮ ﺧﻂ ﻣﺴﺘﻘﻴﻢ ﺃﻳﻀﺎ )`‪ (ab‬ﻣﻦ ﺗﺄﺛﲑ ﻋﺰﻡ ﺍﻹﻟﺘﻮﺍﺀ ﺍﳌـﺴﺒﺐ ﱃ ﺑﺎﻟﻘـﻀﻴﺐ‬ ‫ﻭﳏﺪﺛﺎ ﺯﺍﻭﻳﺔ ﻗﺺ ﻋﻨﺪ ﺍﻟﻄﺮﻑ ﺍﳌﺜﺒﺖ )‪ (Φ‬ﻭﺯﺍﻭﻳﺔ ﺩﻭﺍﺭﻥ ﺑﲔ ﺍﻟﻮﺿﻊ ﺍﻷﺻﻠﻰ ﻟﻨﺼﻒ ﺍﻟﻘﻄـﺮ )‪(ob‬‬ ‫ﻭﺍﻟﻮﺿﻊ ﺍﳉﺪﻳﺪ ﺑﻌﺪ ﺍﻟﻠﻰ )`‪ (ob‬ﻭﻫﺬﻩ ﺍﻟﺰﺍﻭﻳﺔ ﻫﻰ )‪ (θ‬ﻛﻤﺎ ﻫﻮ ﻣﺒﲔ ﺑﺎﻟﺸﻜﻞ ) ‪٠(١٤-٥‬‬ ‫ﺑﻔﺮﺽ ﺃﻥ‪:‬‬ ‫ ﻃﻮﻝ ﺍﻟﻘﻀﻴﺐ ﺍﳌﺨﺘﱪ = ‪L‬‬‫ ﻧﺼﻒ ﻗﻄﺮ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻠﻘﻀﻴﺐ = ‪R‬‬‫ ﻧﺼﻒ ﻗﻄﺮ ﺃﻯ ﻣﻘﻄﻊ ﺩﺍﺋﺮﻯ ﺩﺍﺧﻞ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ = ‪r‬‬‫ ﻋﺰﻡ ﺍﻻﻟﺘﻮﺍﺀ ﺍﳌﺆﺛﺮ = ‪T‬‬‫ ﺯﺍﻭﻳﺔ ﺍﻧﻔﻌﺎﻝ ﺍﻟﻘﺺ = ‪Φ‬‬‫ ﺯﺍﻭﻳﺔ ﺍﻟﺪﻭﺍﺭﻥ ) ﺯﺍﻭﻳﺔ ﺍﻟﻠﻰ ( = ‪θ‬‬‫‪ -‬ﻣﻌﺎﻳﺮ ﺍﳉﺴﺎﺀﺓ )ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ ﰱ ﺍﻟﻘﺺ( = ‪G‬‬

‫ ﺇﺟﻬﺎﺩ ﻗﺺ ﺍﻻﻟﺘﻮﺍﺀ ﻋﻨﺪ ﻧﺼﻒ ﻗﻄﺮ )‪ ) (R‬ﺃﻯ ﻋﻨﺪ ﺍﻟﻨﻘﻂ ﺍﳋﺎﺭﺟﻴﺔ ﻟﻠﻤﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ( = ‪qR‬‬‫ ﺇﺟﻬﺎﺩ ﻗﺺ ﺍﻻﻟﺘﻮﺍﺀ ﻋﻨﺪ ﻧﺼﻒ ﻗﻄﺮ )‪ ) (r‬ﺃﻯ ﻋﻨﺪ ﺃﻯ ﻧﺼﻒ ﻗﻄﺮ ﺩﺍﺧﻞ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ( = ‪qr‬‬‫ ﻋﺰﻡ ﺍﻟﻘﺼﻮﺭ ﺍﻟﺬﺍﺗﻰ ﺍﻟﻘﻄﱮ ﻟﻠﻤﻘﻄﻊ = ‪Ip‬‬‫ﻭﻫﻨﺎ ﻳﻜﻮﻥ‪:‬‬

‫ا‪#‬ل ا =‬

‫إد ا ‬ ‫ او ا ) اءة(‬

‫@@‬

‫‪١٠٨‬‬


@ @@Òì©@ôŠöa…@ÊbĐÓ@MR ٠‫( ﻳﻮﺿﺢ ﺷﻜﻞ ﺇﺟﻬﺎﺩ ﻗﺺ ﺍﻻﻟﺘﻮﺍﺀ ﺇﺫﺍ ﻛﺎﻥ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻣﺴﺘﺪﻳﺮ ﻭﳎﻮﻑ‬١٥-٥) ‫ﺷﻜﻞ‬ @@ @ @ D1 D2 @@ @@ @ @Òì©@Ší†nß@ÉĐÔ½@ó–Óþa@õaìnÛ⁄a@—Ó@…bèug@HQUMUI@ÝØ‘

‫( ﻭﻛـﺬﻟﻚ ﺯﺍﻭﻳـﺔ‬qmax) ‫( ﻳﻮﺿﺢ ﻗﻴﻢ ﺍﻹﺟﻬﺎﺩ ﺍﻷﻗﺼﻰ ﻟﻘﺺ ﺍﻹﻟﺘﻮﺍﺀ‬١-٥) ‫ﻭﻋﻤﻮﻣﹰﺎ ﻓﺈﻥ ﺟﺪﻭﻝ‬ :‫( ﻟﺒﻌﺾ ﺍﳌﻘﺎﻃﻊ ﺍﳌﺴﺘﻌﺮﺿﺔ ﺍﻟﺪﺍﺋﺮﻳﺔ ﻭﻏﲑ ﺍﻟﺪﺍﺋﺮﻳﺔ‬θ) ‫ﺍﻹﻟﺘﻮﺍﺀ ﺍﳌﺼﺎﺣﺒﺔ‬ @ @òíŠöa†Ûa@Ëë@òíŠöa†Ûa@pbÇbĐÔÜÛ@õaìnÛüa@òíëa‹ë@ó–Óþa@õaìnÛüa@—Ó@…bèug@HQMUI@Þë†u

qmax 0&1 ‫ ء‬2 & 345 16.T qmax =

qmax =

πD

θ=

3

16.D1.T 4

θ=

4

π(D1 – D2 ) 16.T

qmax =

3

π D1 .

θ=

D23

4.8 .T qmax =

D

θ=

3

1.8D qmax = ( 3+

D

20T qmax =

D

3

3

T ).

B.D

2

‫ ء‬-. /

θ

θ=

32 πD

()* +,

@ @@ôŠöa…

T.L

. 4

D

G

@ @@Òì©@ôŠöa…

32

. T.L 4 4 π (D1 – D2 ) G 16(D12 + D22) 3

π D1 . 7.11 D

4

G

40 B D

4

D2

G

θ= D . 4

@ @—Óbã@ÉĐÓ

@ @@ÉiŠß

D D

T.L . G

D

@ @@ÝîĐnß @ @B>D @ @B < 6D

@ @Êý™þa@ôëbnß@sÜrß

T.L G D

١٠٩

@@

D1

B

40

D1

T.L .

T.L

.

2

D23

D2


‫‪@ @@õaìnÛüa@—Ó@‰bjna@RMTMU‬‬ ‫ﻻ ﺗﻨﺺ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻋﻠﻰ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻹﻟﺘﻮﺍﺀ ﻛﺎﺧﺘﺒﺎﺭ ﻗﺒﻮﻝ ﻟﻠﻤﻌﺎﺩﻥ ﺇﻻ ﰱ ﺣﺎﻻﺕ ﳏﺪﺩﺓ‬ ‫ﺧﺎﺻﺔ ﻭﻟﻜﻨﻪ ﺍﺧﺘﺒﺎﺭ ﻫﺎﻡ ﳚﺮﻯ ﻣﻌﻤﻠﻴﺎ ﻟﺒﻴﺎﻥ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻠﻤﻮﺍﺩ ﰱ ﺍﻟﻘﺺ ﺣﻴﺚ ﺃﻥ ﺍﻹﻟﺘـﻮﺍﺀ‬ ‫ﻫﻮ ﺣﺎﻟﺔ ﻗﺺ ﺧﺎﻟﺺ ﻷﻥ ﺇﻧﺰﻻﻕ ﺍﳌﻘﺎﻃﻊ ﺍﳌﺴﺘﻌﺮﺿﺔ ﻋﻠﻰ ﺑﻌﻀﻬﺎ ﺍﻟﺒﻌﺾ ﻏﲑ ﻣﺼﺤﻮﺑﺔ ﺑﻌﺰﻡ ﺍﳓﻨـﺎﺀ‬ ‫ﻛﻤﺎ ﰱ ﺣﺎﻟﺔ ﺍﻟﻘﺺ ﺍﳌﺒﺎﺷﺮ‪ .‬ﻛﻤﺎ ﺃﻧﻪ ﳚﺮﻯ ﺃﻳﻀﺎ ﺍﺧﺘﺒﺎﺭ ﺍﻹﻟﺘﻮﺍﺀ ﳌﻌﺮﻓﺔ ﻣﺪﻯ ﻣﻘﺎﻭﻣﺔ ﺃﺟﺰﺍﺀ ﺍﳌﺎﻛﻴﻨﺎﺕ‬ ‫ﺃﻭ ﺍﳌﻨﺸﺂﺕ ﲢﺖ ﺗﺄﺛﲑ ﺍﻹﻟﺘﻮﺍﺀ ﻭﺫﻟﻚ ﻟﻠﻤﻘﺎﻃﻊ ﺍﳌﺴﺘﺪﻳﺮﺓ ﻭﺍﻟﻐﲑ ﻣﺴﺘﺪﻳﺮﺓ‪ .‬ﻭﻳﺴﺘﺨﺪﻡ ﺍﺧﺘﺒﺎﺭ ﺍﻹﻟﺘﻮﺍﺀ‬ ‫ﺃﻳﻀﺎ ﻟﺪﺭﺍﺳﺔ ﺗﺄﺛﲑ ﻋﻤﻠﻴﺎﺕ ﺍﳌﻌﺎﻣﻠﺔ ﺍﳊﺮﺍﺭﻳﺔ ﺍﳌﺨﺘﻠﻔﺔ ﻭﺧﺼﻮﺻﹸﺎ ﻟﻸﺟﺰﺍﺀ ﺍﳌﻌﺮﺿﺔ ﻟﻠﻌﻤﻠﻴﺎﺕ ﺍﻟﱴ ﺗﺆﺛﺮ‬ ‫ﻛﺜﲑﹰﺍ ﻋﻠﻰ ﺍﳌﻌﺪﻥ ﻗﺮﺏ ﺍﻟﺴﻄﺢ‪ .‬ﻭﻳﺴﺘﻌﻤﻞ ﺟﺰﺀ ﺍﳌﻌﺪﻥ ﺑﻜﺎﻣﻞ ﻣﻘﺎﺳﻪ ﺍﻟﻄﺒﻴﻌﻰ ﻛﻤﺎ ﰱ ﺣﺎﻟـﺔ ﳏـﻮﺭ‬ ‫ﻋﺠﻼﺕ ﺍﻟﺴﻴﺎﺭﺍﺕ‪.‬‬ ‫ﺑﺎﻟﻨﺴﺒﺔ ﻟﻌﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻓﺈﻧﻪ ﻻ ﻳﻮﺟﺪ ﻟﺸﻜﻞ ﻭﺃﺑﻌﺎﺩ ﻋﻴﻨﺔ ﺇﺧﺘﺒﺎﺭ ﺍﻹﻟﺘﻮﺍﺀ ﻣﻮﺍﺻﻔﺎﺕ ﻗﻴﺎﺳـﻴﺔ ﺧﺎﺻـﺔ‬ ‫ﻭﳏﺪﺩﺓ‪ ،‬ﻭﻟﻜﻦ ﺷﻜﻞ ﺍﻟﻌﻴﻨﺔ ﻏﺎﻟﺒﺎ ﻣﺎ ﺗﻜﻮﻥ ﺃﺳﻄﻮﺍﻧﻴﺔ ﺍﻟﺸﻜﻞ ﺃﻯ ﺩﺍﺋﺮﻳﺔ ﺍﳌﻘﻄﻊ ﻣﻊ ﺍﻷﺧﺬ ﰱ ﺍﻻﻋﺘﺒﺎﺭ‬ ‫ﺃﻥ ﻳﻜﻮﻥ ﻗﻄﺮ ﻣﻘﻄﻊ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﺃﻗﻞ ﻣﻦ ﻗﻄﺮ ‪‬ﺎﻳﱴ ﺍﻟﻌﻴﻨﺔ ﻭﺍﳌﺮﻛﺒﺘﺎﻥ ﰱ ﻣﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻟـﻀﻤﺎﻥ‬ ‫ﻋﺪﻡ ﺣﺪﻭﺙ ﻛﺴﺮ ﺃﻭ ﺍ‪‬ﻴﺎﺭ ﻋﻨﺪ ﺇﺣﺪﻯ ﺍﻟﻨﻬﺎﻳﺘﲔ ﻭﻳﻜﻮﻥ ﺍﻟﻜﺴﺮ ﰱ ﺟﺴﻢ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘـﱪﺓ ﻟـﻀﻤﺎﻥ‬ ‫ﺻﺤﺔ ﻧﺘﺎﺋﺞ ﺍﻻﺧﺘﺒﺎﺭ‪ .‬ﻛﻤﺎ ﺃﻧﻪ ﳚﺐ ﺃﻥ ﻳﻜﻮﻥ ﻫﻨﺎﻙ ﲡﺎﻭﻳﻒ ﺑﻜﻞ ﻣﻦ ‪‬ﺎﻳﱴ ﺍﻟﻌﻴﻨﺔ ﺣﱴ ﻳﺴﻬﻞ ﺗﺮﻛﻴﺒﻬﺎ‬ ‫ﲟﺎﻛﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻟﺘﺮﺗﻜﺰ ﻋﻠﻴﻬﺎ ﺍﻟﻌﻴﻨﺔ ﻛﻤﺎ ﰱ ﺷﻜﻞ )‪(١٦-٥‬‬

‫‘‪@ @õaìnÛ⁄a@‰bjna@òäîÇ@HQVMUI@ÝØ‬‬

‫ﻳﺘﻢ ﺍﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻹﻟﺘﻮﺍﺀ ﻋﻠﻰ ﻣﺎﻛﻴﻨﺔ ﺧﺎﺻﺔ ﺑﺎﻹﻟﺘﻮﺍﺀ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ ،(١٧-٥‬ﻭﻫـﺬﺍ‬ ‫ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﳌﺎﻛﻴﻨﺎﺕ ﻟﻪ ﻓﻜﲔ ﺗﺜﺒﻴﺖ ﺑﻴﻨﻬﻤﺎ ﺍﻟﻌﻴﻨﺔ ﺍﳌﻄﻠﻮﺏ ﺍﺧﺘﺒﺎﺭﻫﺎ‪ ،‬ﻭﻳﺘﺤﺮﻙ ﺃﺣﺪ ﻫـﺬﻳﻦ ﺍﻟﻔﻜـﲔ‬ ‫ﺩﺍﺋﺮﻳﺎ ﻣﺴﺒﺒﹰﺎ ﻋﺰﻡ ﺇﻟﺘﻮﺍﺀ ﺑﺎﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ‪ ،‬ﺃﻣﺎ ﺍﻟﻔﻚ ﺍﻵﺧﺮ ﻣﺰﻭﺩ ﺑﺜﻘﻞ ﺑﻨﺪﻭﱃ ﻳﻌﻤﻞ ﻋﻠﻰ ﻣﻮﺍﺯﻳﺔ ﻋـﺰﻡ‬ ‫ﺍﻹﻟﺘﻮﺍﺀ ﺍﳌﺬﻛﻮﺭ‪ ،‬ﺃﻭ ﺑﺄﻯ ﺃﺳﻠﻮﺏ ﺁﺧﺮ‪ ،‬ﻛﻤﺎ ﻳﻮﺟﺪ ﺑﺎﳌﺎﻛﻴﻨﺔ ﻣﻘﺎﺱ ﻣﺪﺭﺝ ﻟﺒﻴﺎﻥ ﻋﺰﻡ ﺍﻹﻟﺘﻮﺍﺀ ﺍﳌﺆﺛﺮ ﺑﻪ‬ ‫ﻭﺃﻳﻀﺎ ﻣﻘﻴﺎﺱ ﻟﺒﻴﺎﻥ ﺍﻹﻟﺘﻮﺍﺀ‪.‬‬ ‫‪١١٠‬‬


‫@@‬ ‫‘‪@ @@õaìnÛ⁄a@‰bjna@òäî×bß@HQWMUI@ÝØ‬‬

‫ﳝﻜﻦ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻹﻟﺘﻮﺍﺀ ﻋﻠﻰ ﻋﻴﻨﺎﺕ ﻣﻦ ﺍﳌﻌﺎﺩﻥ ﺍﳌﺨﺘﻠﻔﺔ ﺳﻮﺍﺀ ﻛﺎﻧﺖ ﻣﻄﻠﻴﺔ ﺃﻭ ﻗﺼﻔﺔ‪ ،‬ﺣﻴﺚ ﺃﻧـﻪ‬ ‫ﳚﺮﻯ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ﺍﳌﻄﻴﻠﺔ ﻟﺘﻌﻴﲔ ﻣﻘﺎﻭﻣﺘﻪ ﺍﻟﻘﺼﻮﻯ ﻟﻠﻘﺺ ﻭﻛﺬﻟﻚ ﺍﳋـﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴـﺔ ﰱ‬ ‫ﺍﻹﻟﺘﻮﺍﺀ‪ ،‬ﺃﻣﺎ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﻤﻮﺍﺩ ﺍﻟﻘﺼﻔﺔ ﻓﺈﻧﻪ ﻻ ﻳﺴﺘﻌﻤﻞ ﻏﺎﻟﺒﺎ ﻟﺒﻴﺎﻥ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻘﺺ ﻷﻥ ﺍﳌﻌﺎﺩﻥ ﺍﻟﻘﺼﻔﺔ ﺇﺫﺍ‬ ‫ﺗﻌﺮﺿﺖ ﻟﻌﺰﻡ ﺇﻟﺘﻮﺍﺀ ﻓﺈ‪‬ﺎ ﺗﻨﻜﺴﺮ ﺑﺎﻟﺸﺪ ﺍﻟﻀﻠﻌﻰ ﺍﻟﻘﻄﺮﻯ ﻗﺒﻞ ﺃﻥ ﻳﺼﻞ ﺍﳌﻌﺪﻥ ﺇﱃ ﻣﻘﺎﻭﻣﺘﻪ ﺍﻟﻘـﺼﻮﻯ‬ ‫ﻟﻠﻘﺺ ﻭﻟﻜﻦ ﳚﺮﻯ ﻫﺬﺍ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻠﻰ ﺍﳌﻌﺎﺩﻥ ﺍﻟﻘﺼﻔﺔ ﺑﻐﺮﺽ ﺩﺭﺍﺳﺔ ﺑﻌـﺾ ﺍﳋـﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴـﺔ‬ ‫ﺍﻵﺧﺮﻯ ﺃﻭ ﻟﻠﻤﻘﺎﺭﻧﺔ ﺑﲔ ﺍﳌﻌﺎﺩﻥ‪ .‬ﻳﺘﻢ ﻗﻴﺎﺱ ﺃﺑﻌﺎﺩ ﺍﻟﻌﻴﻨﺔ ﺍﳌﻄﻠﻮﺏ ﺇﺧﺘﺒﺎﺭﻫﺎ ﰒ ﺗﺜﺒﺖ ﺍﻟﻌﻴﻨـﺔ ﲟﺎﻛﻴﻨـﺔ‬ ‫ﺍﻻﺧﺘﺒﺎﺭ ﻭﻳﺆﺛﺮ ﻋﻠﻴﻬﺎ ﺑﻌﺰﻡ ﺇﻟﺘﻮﺍﺀ )‪ (T‬ﻣﺘﺪﺭﺝ ﰱ ﺍﻟﻘﻴﻤﺔ ﻣﻦ ﺍﻟﺼﻔﺮ ﺣﱴ ﻛﺴﺮ ﺍﻟﻌﻴﻨﺔ ﻭﺗﺴﺠﻞ ﺯﺍﻭﻳـﺔ‬ ‫ﺍﻹﻟﺘﻮﺍﺀ ﺍﳌﺼﺎﺣﺒﺔ ﻟﻜﻞ ﻋﺰﻡ ﺍﻟﺘﻮﺍﺀ ﻭﻟﺘﻜﻦ )‪.(θ‬‬ ‫‪@ @õaìnÛ⁄a@óÏ@ñn‚½a@pbäîÈÛa@óÏ@ŠØÛa@ÝØ‘@@SMTMU‬‬ ‫ﻳﺘﻢ ﺍﻟﻜﺴﺮ ﰱ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﰱ ﺍﺧﺘﺒﺎﺭ ﻗﺺ ﺍﻹﻟﺘﻮﺍﺀ ﰱ ﻣﺴﺘﻮﻯ ﻋﻤﻮﺩﻯ ﻋﻠﻰ ﳏﻮﺭ ﺍﻟﻌﻴﻨﺔ ﺃﻯ ﻋﻠـﻰ‬ ‫ﻣﺴﺘﻮﻯ ﻣﻮﺍﺯﻯ ﻟﻠﻤﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻭﺫﻟﻚ ﻧﺘﻴﺠﺔ ﺗﺄﺛﲑ ﻗﺺ ﺍﻹﻟﺘﻮﺍﺀ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟـﺸﻜﻞ )‪-٥‬‬ ‫‪ ،(١٨‬ﻷﻥ ﺍﳌﻌﺎﺩﻥ ﺍﳌﻄﻴﻠﺔ ﺿﻌﻴﻔﺔ ﰱ ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﻋﻨﻬﺎ ﰱ ﺇﺟﻬﺎﺩ ﺍﻟﺸﺪ ﺃﻭ ﺇﺟﻬـﺎﺩ ﺍﻟـﻀﻐﻂ ﺃﻯ ﺃﻥ‬ ‫ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﻫﻮ ﺍﻟﺬﻯ ﻳﺘﺤﻜﻢ ﰱ ﻣﺪﻯ ﻣﻘﺎﻭﻣﺔ ﻫﺬﻩ ﺍﳌﻌﺎﺩﻥ ﻟﻠﻜﺴﺮ‪ .‬ﺃﻣﺎ ﺍﳌﻌﺎﺩﻥ ﺍﻟﻘﺼﻔﺔ ﻳﺘﻢ ﻛﺴﺮﻫﺎ‬ ‫ﺑﺎﻹﻟﺘﻮﺍﺀ ﻋﻠﻰ ﺷﻜﻞ ﺣﻠﺰﻭﱏ ﻧﺎﺗﺞ ﻣﻦ ﻛﺴﺮﻫﺎ ﻋﻠﻰ ﻣﺴﺘﻮﻳﺎﺕ ﲤﺎﺱ ﺳﻄﺤﻬﺎ ﻭﺗﻌﻤﻞ ‪٤٥‬ﻩ ﻣﻊ ﳏـﻮﺭ‬ ‫ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻛﻤﺎ ﻫﻮ ﻣﻮﺿﺢ ﺑﺎﻟﺸﻜﻞ )‪ ،(١٩-٥‬ﻭﺫﻟﻚ ﺍﻟﻜﺴﺮ ﻧﺘﻴﺠﺔ ﺗﺄﺛﲑ ﺇﺟﻬﺎﺩ ﺍﻟﺸﺪ ﺍﻟـﻀﻠﻌﻰ‬ ‫ﺍﻟﻘﻄﺮﻯ ﻷﻥ ﻫﺬﻩ ﺍﳌﻌﺎﺩﻥ ﺿﻌﻴﻔﺔ ﰱ ﺇﺟﻬﺎﺩ ﺍﻟﺸﺪ ﻋﻨﻬﺎ ﰱ ﺇﺟﻬﺎﺩ ﺍﻟﻘﺺ ﺃﻭ ﺇﺟﻬـﺎﺩ ﺍﻟـﻀﻐﻂ ﺃﻯ ﺃﻥ‬ ‫ﺇﺟﻬﺎﺩ ﺍﻟﺸﺪ ﻫﻮ ﺍﻟﺬﻯ ﻳﺘﺤﻜﻢ ﰱ ﻣﺪﻯ ﻣﻘﺎﻭﻣﺔ ﻫﺬﻩ ﺍﳌﻌﺎﺩﻥ ﻟﻠﻜﺴﺮ‪.‬‬ ‫‪١١١‬‬


Mt

@@ @ @õaìnÛ⁄a@‰bjna@óÏ@òÜîĐ½a@æ…bÈ½a@‰bîèãg@HQXMUI@ÝØ‘

Mt

@@ @@ @ @õaìnÛ⁄a@‰bjna@óÏ@òÐ–ÔÛa@æ…bÈ½a@‰bîèãg@HQYMUI@ÝØ‘

١١٢


‫ ‬ ‫ ء ‬ ‫ﺍﻟﺒﻨﺎﺀ ﺍﻟﺒﻠﻮﺭﻱ ﻫﻮ ﺍﻟﻄﺮﻳﻘﺔ ﺍﻟﱴ ﺗﺘﺠﻤﻊ ‪‬ﺎ ﺍﻟﺬﺭﺍﺕ ﻣﻊ ﺑﻌﻀﻬﺎ ﰱ ﺑﻨﺎﺀ ﻓﺮﺍﻏﻰ ﻣﻨﺘﻈﻢ‪ .‬ﺍﻟﺒﻠﻮﺭﺓ ﺗﺘﻜﻮﻥ‬ ‫ﻣﻦ ﳎﻤﻮﻋﺔ ﻣﻦ ﺍﻟﺬﺭﺍﺕ ﻋﻠﻰ ﺩﺭﺟﺔ ﻋﺎﻟﻴﺔ ﻣﻦ ﺍﻟﺘﺮﺗﻴﺐ ﺍﳍﻨﺪﺳﻰ ﺑﺎﻟﻨﺴﺒﺔ ﻟﺒﻌﻀﻬﺎ ﺍﻟﺒﻌﺾ ﻭﻫﺬﺍ ﻣﺎﻳﻔﺮﻗﻬﺎ‬ ‫ﻋﻦ ﺍﳌﻮﺍﺩ ﺍﻻﺧﺮﻯ ﺍﻟﻼﺑﻠﻮﺭﻳﺔ ﺣﻴﺚ ﻻﻳﻮﺟﺪ ﻓﻴﻬﺎ ﺗﺮﺗﻴﺐ ﻣﻌﲔ ﻟﻠﺬﺭﺍﺕ‪ .‬ﻭﺗﺘﺒﻊ ﲨﻴﻊ ﺍﳌﻌﺎﺩﻥ ﺍﻟﺼﻮﺭﺓ‬ ‫ﺍﻟﺒﻠﻮﺭﻳﺔ ﺑﻴﻨﻤﺎﻳﺘﺒﻊ ﺍﻟﺰﺟﺎﺝ ﻭﻣﻌﻈﻢ ﺍﻟﻠﺪﺍﺋﻦ ﺍﳌﻮﺍﺩ ﺍﻟﻼﺑﻠﻮﺭﻳﺔ‪ .‬ﻭﳚﺪﺭ ﺍﻻﺷﺎﺭﺓ ﺍﱃ ﺍﻥ ﺍﻟﺘﺮﺗﻴﺐ ﺍﳍﻨﺪﺳﻰ‬ ‫ﻟﻠﺬﺭﺍﺕ ﰱ ﺍﳌﻮﺍﺩ ﺍﻟﺒﻠﻮﺭﻳﺔ ﻳﺆﺩﻯ ﺍﱃ ﺗﻮﺍﺟﺪ ﺑﻨﺎﺀ ﻣﻨﺘﻈﻢ ﻭﻣﺰﺩﺣﻢ ﺑﺎﻟﺬﺭﺍﺕ ﳑﺎ ﻳﺰﻳﺪ ﻣﻦ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻮﺍﺩ‬ ‫ﺍﻟﺒﻠﻮﺭﻳﺔ ﻟﻠﻘﻮﻯ ﺍﳋﺎﺭﺟﻴﺔ ﻋﻨﻬﺎ ﰱ ﺍﳌﻮﺍﺩ ﺍﻟﻼﺑﻠﻮﺭﻳﺔ‪ .‬ﺃﻳﻀﺎ ﻣﻦ ﺧﺼﺎﺋﺺ ﻫﺬﺍ ﺍﻟﺒﻨﺎﺀ ﺍﳌﻨﺘﻈﻢ ﺍﻛﺴﺎﺏ‬ ‫ﺍﻟﻠﻤﻌﺎﻥ ﻭﺍﻟﱪﻳﻖ ﻭﺍﻟﻘﺎﺑﻠﻴﺔ ﻟﻠﺘﻮﺻﻴﻞ ﺍﳊﺮﺍﺭﻱ ﻭﺍﻟﻜﻬﺮﺑﺎﺋﻲ ﻭﺍﻟﺘﺸﻜﻴﻞ ﻟﻠﻤﻌﺪﻥ ‪ ،‬ﻭﲣﺘﻠﻒ ﻫﺬﻩ ﺍﳋﻮﺍﺹ‬ ‫ﺑﺎﺧﺘﻼﻑ ﺍﻻﲡﺎﻫﺎﺕ ﻭﻻ ﺗﻌﺘﻤﺪ ﻫﺬﻩ ﺍﳋﻮﺍﺹ ﻋﻠﻰ ﺍﻟﺘﺮﻛﻴﺐ ﺍﻟﻜﻴﻤﻴﺎﺋﻲ ﻓﻘﻂ ﻭﻟﻜﻦ ﻫﻨﺎﻙ ﺑﻌﺾ‬ ‫ﺍﻟﻈﻮﺍﻫﺮ ﳚﺐ ﺃﻥ ﺗﺆﺧﺬ ﺑﺎﻻﻋﺘﺒﺎﺭ ﻣﺜﻞ ‪:‬‬ ‫‪Space lattice pa‰ˆÜÛ@ïËaŠÐÛa@ï†äa@kîmÛa‬‬ ‫…‪Close packing õbäjÛa@pa†yë@í@l‰bÔnÛa@òu‰‬‬ ‫‪Chemical bond pa‰ˆÛa@í@òîöbîàîØÛa@ÁiaëŠÛa‬‬

‫ﻭﺗﺘﺮﺗﺐ ﺍﳌﻌﺎﺩﻥ ﰲ ﺍﻟﺸﺒﻜﺎﺕ ﺍﻟﺒﻠﻮﺭﻳﺔ ﺑﺄﺷﻜﺎﻝ ﳐﺘﻠﻔﺔ ‪ ،‬ﻭﻟﻜﻞ ﻣﻌﺪﻥ ﺷﻜﻞ ﺑﻠﻮﺭﻱ ﺧﺎﺹ ﺑـﻪ‪ .‬ﻭﻗـﺪ‬ ‫ﺗﺘﻘﺎﺭﺏ ﺍﳌﻌﺎﺩﻥ ﺫﺍﺕ ﺍﻷﺷﻜﺎﻝ ﺍﻟﺒﻠﻮﺭﻳﺔ ﰲ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﺣﱴ ﻭﺇﻥ ﺍﺧﺘﻠﻔﺖ ﺑﻌـﺾ ﺍﳋـﻮﺍﺹ‬ ‫ﺍﻟﻜﻴﻤﻴﺎﺋﻴﺔ ‪ ،‬ﻭﻫﻨﺎﻙ ﺑﻌﺾ ﺍﳌﻌﺎﺩﻥ ﻣﺜﻞ ﺍﳊﺪﻳﺪ ﻭﺍﳌﻨﺠﻨﻴﺰ ﻭﺍﻟﻜﻮﺑﻠﺖ ﻭﺍﻟﻘﺼﺪﻳﺮ ﺗﻮﺟﺪ ﻋﻠﻰ ﺃﻛﺜﺮ ﻣـﻦ‬ ‫ﺷﻜﻞ ﺑﻠﻮﺭﻱ ﺑﺎﺧﺘﻼﻑ ﺩﺭﺟﺔ ﺍﳊﺮﺍﺭﺓ ﻭﻫﺬﺍ ﻣﺎ ﻳﻌﺮﻑ ﺑﺎﻟﺘﺂﺻـﻞ ﺃﻭ ﺗﻌـﺪﺩ ﺍﻷﺷـﻜﺎﻝ‬

‫‪Allotropic‬‬

‫ﻭﲣﺘﻠﻒ ﺍﳋﻮﺍﺹ ﻛﻠﻴﹰﺎ ﺑﺎﺧﺘﻼﻑ ﺍﻟﺸﺒﻜﺎﺕ ﺍﻟﺒﻠﻮﺭﻳﺔ ‪ ،‬ﻭﻳﺴﺘﻔﺎﺩ ﻣﻦ ﻫﺬﻩ ﺍﻟﻈﺎﻫﺮﺓ ﰲ ﺗـﺸﻜﻴﻞ ﺑﻌـﺾ‬ ‫ﺍﳌﻌﺎﺩﻥ ﻋﻠﻰ ﺍﻟﺴﺎﺧﻦ‪.‬‬ ‫‪ 1-6‬‬

‫ﻭﺣﺪﺓ ﺍﳋﻠﻴﺔ ﻫﻰ ﺍﺻﻐﺮ ﳎﻤﻮﻋﺔ ﻣﻦ ﺍﻟﺬﺭﺍﺕ ﺫﺍﺕ ﻭﻗﻊ ﻣﺘﻨﺎﺳﻖ ﻭﳍﺎ ﲨﻴﻊ ﺧﺼﺎﺋﺺ ﺍﻟﺒﻠﻮﺭﺓ ﺑﺄﻛﻤﻠﻬﺎ‪.‬‬ ‫ﻭﻳﺆﺩﻯ ﺗﻜﺮﺍﺭ ﻭﺣﺪﺓ ﺍﳋﻠﻴﺔ ﰱ ﲨﻴﻊ ﺍﻻﲡﺎﻫﺎﺕ ﺍﱃ ﺗﻜﻮﻳﻦ ﺍﻟﺸﺒﻜﺔ ﺍﻟﺒﻠﻮﺭﻳﺔ‪ .‬ﻭﻳﺒﲔ ﺷﻜﻞ ) ‪( ١-١‬‬ ‫ﳐﻄﻄﺎ ﻟﻮﺣﺪﺓ ﺍﳋﻠﻴﺔ ﰱ ﺷﻜﻠﻬﺎ ﺍﻟﻌﺎﻡ ﻋﻠﻰ ﺍﶈﺎﻭﺭ ﺍﻟﺜﻼﺛﺔ ﻭﻛﺬﻟﻚ ﺍﻃﻮﺍﻝ ﺍﺿﻼﻉ ﺍﳋﻠﻴﺔ‪ .‬ﻭﻧﺴﺘﻄﻴﻊ ﺍﻥ‬ ‫‪١١٣‬‬


‫ﻧﺘﻌﺮﻑ ﻋﻠﻰ ﺻﻔﺎﺕ ﻭﺧﺼﺎﺋﺺ ﻭﺣﺪﺓ ﺍﳋﻠﻴﺔ ﺑﺼﻮﺭﺓ ﺃﺳﻬﻞ ﺑﻜﺜﲑ ﻣﻦ ﺍﻟﺘﻌﺮﻑ ﻋﻠﻰ ﺻﻔﺎﺕ ﺍﻟﺒﻠﻮﺭﺓ‬ ‫ﺍﻟﱴ ﲢﻮﻯ ﻣﻼﻳﲔ ﺍﻟﺬﺭﺍﺕ‪ .‬ﻭﻧﺸﲑﻫﻨﺎ ﺍﱃ ﺍﻥ ﺍﻟﺒﻠﻮﺭﺓ ﺗﺘﻜﻮﻥ ﻣﻦ ﺑﻨﺎﺀ ﻭﺣﺪﺓ ﺍﳋﻼﻳﺎ ﻣﻊ ﺑﻌﻀﻬﺎ ﻣﺜﻠﻤﺎ‬ ‫ﻳﺘﻜﻮﻥ ﺍﻟﺒﻨﺎﺀ ﻣﻦ ﳎﻤﻮﻋﺔ ﻗﻮﺍﻟﺐ ﻣﺘﺮﺍﺻﺔ‪ .‬ﻟﺬﺍ ﻓﺄﻧﺔ ﻣﻦ ﺍﳌﺘﻮﻗﻊ ﺍﻥ ﺗﻜﻮﻥ ﺍﺳﻄﺢ ﺑﻨﻴﺎﻥ ﻫﺬﺓ ﺍﻟﺒﻠﻮﺭﺍﺕ‬ ‫ﻣﺴﺘﻮﻳﺎ ﻟﻜﻨﺔ ﻧﺘﻴﺠﺔ ﻟﻠﻌﻮﺍﻣﻞ ﺍﳋﺎﺭﺟﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ ﻗﺪ ﺗﺘﻐﲑ ﺍﻻﺳﻄﺢ ﺍﳋﺎﺭﺟﻴﺔ ﺑﻴﻨﻤﺎ ﻳﺘﺒﻘﻰ ﺍﻟﺒﻨﻴﺎﻥ ﺍﻟﺪﺍﺧﻠﻰ‬ ‫ﻟﻠﺒﻠﻮﺭﺓ ﺛﺎﺑﺘﺎ ﻣﻜﻮﻧﺎ ﻣﻦ ﻭﺣﺪﺍﺕ ﺧﻼﻳﺎ ﻣﺴﺘﻮﻳﺔ ﺍﻻﺳﻄﺢ ﻭﻳﻄﻠﻖ ﻋﻠﻰ ﺍﻟﺒﻠﻮﺭﺓ ﺫﺍﺕ ﺍﻻﺳﻄﺢ ﻏﲑ‬ ‫ﺍﳌﺴﺘﻮﻳﺔ ﺑﺎﳊﺒﻴﺒﺔ‪ .‬ﻭﻻﺗﺘﻐﲑ ﺍﺳﻄﺢ ﻭﺷﻜﻞ ﻭﺣﺪﺍﺕ ﺍﳋﻼﻳﺎ ﺩﺍﺧﻞ ﺍﳊﺒﻴﺒﺔ ﻋﻨﻬﺎ ﰱ ﺍﻟﺒﻠﻮﺭﺓ‪ .‬ﻳﻮﺟﺪ ﻣﻦ‬ ‫ﺍﻟﻨﺎﺣﻴﺔ ﺍﻟﻌﻠﻤﻴﺔ ﺍﺭﺑﻌﺔ ﻋﺸﺮ ﺍﺣﺘﻤﺎﻻ ﻟﺘﺮﺗﻴﺐ ﺍﻟﺬﺭﺍﺕ ﺩﺍﺧﻞ ﺍﳋﻼﻳﺎ ﻭﺍﻟﱴ ﺑﺪﻭﺭﻫﺎ ﺗﺘﺒﻊ ﺳﺒﻊ ﻧﻈﻢ ﺑﻠﻮﺭﻳﺔ‬ ‫ﳐﺘﻠﻔﺔ‪ ، .‬ﻭﻫﻲ‪:‬‬ ‫‪@ @êìuìÛa@kÈØß@âbÄã@MQ‬‬ ‫@‪@ @êìuìÛa@ïÇbi‰@âbÄã@@MR‬‬ ‫‪@ @êìuìÛa@ïa† âbÄã@MS‬‬ ‫‪@ @ÝØ’Ûa@ŞîÈ½a@âbÄäÛa@@MT‬‬ ‫‪@ @áöbÔÛa@ŞîÈ½a@âbÄäÛa@MU‬‬ ‫@‪@ @Ýî½a ð…byc@âbÄã@@MV‬‬ ‫@‪@ @NÝî½a@ïqýq@âbÄã@MW‬‬ ‫ﻭﻛﻞ ﻧﻈﺎﻡ ﻳﻮﺻﻒ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻮﺟﻮﺩ ﺛﻼﺛﺔ ﳏﺎﻭﺭ ﻭﳘﻴﺔ ﺗﺴﻤﻰ ﺍﶈﺎﻭﺭ ﺍﻟﺒﻠﻮﺭﻳﺔ‪ ،‬ﺗﺘﻘﺎﻃﻊ ﰲ ﻣﺮﻛﺰ‬ ‫ﺍﻟﺒﻠﻮﺭﺓ‪.‬‬

‫‘‪@ @òqýrÛa@‰ëba@óÜÇ@âbÈÛa@bèÜØ‘@óÏ@òîÜä@ñ†yë@HQMVI@ÝØ‬‬

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‫‪ ê@ ì;uìÛa@kÈØ½a@âbÄäÛa@QMQMV‬ﺗﺘﻌﺎﻣﺪ ﺍﶈﺎﻭﺭ ﺍﻟﺜﻼﺛﺔ ﰲ ﺑﻠﻮﺭﺍﺕ ﻫﺬﺍ ﺍﻟﻨﻈﺎﻡ ﻭﺗﺘﺴﺎﻭﻯ ﺃﻃﻮﺍﳍﺎ‪ ،‬ﻭﻳﻌـﺪ‬ ‫ﺍﳌﻜﻌﺐ ﺃﺑﺴﻂ ﺍﻟﺒﻠﻮﺭﺍﺕ ﺍﳌﻜﻌﺒﻴﺔ‪ .‬ﻭﻣﻦ ﺍﻷﺷﻜﺎﻝ ﺍﻷﺧﺮﻯ ﰲ ﻫﺬﺍ ﺍﻟﻨﻈﺎﻡ ﺍ‪‬ﺴﻢ ﺍﻟﺜﻤﺎﱐ‪ .‬ﻓﻬﻮ ﺫﻭ ﲦﺎﻧﻴﺔ‬ ‫ﺃﻭﺟﻪ‪ ،‬ﻛﻞ ﻭﺟﻪ ﻣﻨﻬﺎ ﳝﺜﻞ ﻣﺜﻠﺜﺎ ﻣﺘﺴﺎﻭﻱ ﺍﻷﺿﻼﻉ‪ .‬ﻭﺗﺘﺒﻠﻮﺭ ﺍﳉﺎﻟﻴﻨﺎ ﻭﺍﻟﺒﲑﺍﻳﺖ ﻭﻓﻘﹰﺎ ﳍﺬﺍ ﺍﻟﻨﻈﺎﻡ‪.‬‬

‫‘‪@ @HoíajÛaI@ñìuìÛa@kÈØ½a@âbÄäÛa@HRMVI@ÝØ‬‬

‫‪ ê@ ì;uìÛa@ïÇb;iŠÛa@âbÄäÛa@@RMQMV‬ﺗﺘﻌﺎﻣﺪ ﺍﶈﺎﻭﺭ ﺍﻟﺜﻼﺛﺔ ﰲ ﺍﻟﺒﻠﻮﺭﺍﺕ ﺭﺑﺎﻋﻴﺔ ﺍﻟﻮﺟﻮﻩ ﻭﻳﺘﺴﺎﻭﻯ ﻃـﻮﻻ‬ ‫ﳏﻮﺭﻳﻦ ﻣﻨﻬﺎ‪ .‬ﻭﻳﻌﺪ ﺍﳌﻮﺷﻮﺭ ﺫﻭ ﺍﳉﻮﺍﻧﺐ ﺍﳌﺴﺘﻄﻴﻠﺔ ﻭﺍﻟﺮﺃﺱ ﻭﺍﻟﻘﺎﻋﺪﺓ ﺍﳌﺮﺑﻌﲔ‪ ،‬ﺃﺑﺴﻂ ﺷﻜﻞ ﻟﺒﻠـﻮﺭﺓ‬ ‫ﺭﺑﺎﻋﻴﺔ ﺍﻟﻮﺟﻮﻩ‪ .‬ﻭﻫﻨﺎﻙ ﺑﻠﻮﺭﺍﺕ ﺃﺧﺮﻯ ﺭﺑﺎﻋﻴﺔ ﺍﻟﻮﺟﻮﻩ ﺗﺸﺒﻪ ﺍﳍﺮﻡ ﺫﺍ ﺍﻟﻮﺟـﻮﻩ ﺍﻟﺜﻤﺎﻧﻴـﺔ‪ .‬ﻭﺗﺘﻜـﻮﻥ‬ ‫ﻭﺟﻮﻫﻬﺎ ﻋﻠﻰ ﺃﺳﺎﺱ ﻣﺜﻠﺜﺎﺕ ﻣﺘﻄﺎﺑﻘﺔ ﻭﻣﺘﺴﺎﻭﻳﺔ ﺍﻟﻀﻠﻌﲔ‪ .‬ﻳﺘﺒﻠﻮﺭ ﺃﻛﺴﻴﺪ ﺍﻟﻘﺼﺪﻳﺮ ﻭﺍﻟﺰﺭﻛﻮﻥ ﻭﻓﻘـﺎ‬ ‫ﻟﻠﻨﻈﺎﻡ ﺭﺑﺎﻋﻲ ﺍﻟﻮﺟﻮﻩ‪.‬‬

‫‘‪@ @HÝíbmëŠÛaI@êìuìÛa@ïÇbiŠÛa@âbÄäÛa@H@SMV@I@ÝØ‬‬

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‫‪ ê@ ì;uìÛa@ïa†;Ûa@âbÄäÛa@@SMQMV‬ﲤﺘﺎﺯ ﺍﻟﺒﻠﻮﺭﺍﺕ ﺍﻟﺴﺪﺍﺳﻴﺔ ﺍﻟﻮﺟﻮﻩ ﺑﺄﺭﺑﻌﺔ ﳏﺎﻭﺭ ﺗﻘﻊ ﺛﻼﺛﺔ ﻣﻨـﻬﺎ ﰲ‬ ‫ﻣﺴﺘﻮﻯ ﺃﻓﻘﻲ‪ ،‬ﻭﻫﻲ ﻣﺘﺴﺎﻭﻳﺔ ﺍﻷﻃﻮﺍﻝ‪ ،‬ﻭﻳﺘﺒﺎﻋﺪ ﻛﻞ ﳏﻮﺭﻳﻦ ﺑﺰﺍﻭﻳﺔ ﻣﻘﺪﺍﺭﻫﺎ ‪ .°١٢٠‬ﺃﻣﺎ ﺍﶈﻮﺭ ﺍﻟﺮﺍﺑﻊ‬ ‫ﻓﻴﻘﻊ ﻋﻤﻮﺩﻳ‪‬ﺎ ﻋﻠﻴﻬﺎ‪ ،‬ﻭﻳﺘﺨﺬ ﺃﻃﻮﺍ ﹰﻻ ﳐﺘﻠﻔﺔ‪ .‬ﻳ‪‬ﻌﺪ ﺍﳌﻮﺷﻮﺭ ﺫﻭ ﺍﻟﻮﺟﻮﻩ ﺍﳌﺴﺘﻄﻴﻠﺔ ﺍﻟﺴﺘﺔ ﺍﳌﻮﺍﺯﻳﺔ ﻟﻠﻤﺤﻮﺭ‬ ‫ﺍﻟﺮﺍﺑﻊ‪ ،‬ﺃﺑﺴﻂ ﺑﻠﻮﺭﺓ ﺳﺪﺍﺳﻴﺔ ﺍﻟﻮﺟﻮﻩ‪ .‬ﻭﺗﺘﺒﻠﻮﺭ ﺍﳌﻌﺎﺩﻥ‪ :‬ﺍﻷﺑﺎﺗﻴﺖ‪ ،‬ﻭﺍﻟﱪﻳﻞ ﺍﻟﺰﺑﺮﺟﺪ ﻭﺍﳉﺮﺍﻓﻴﺖ ﻭﻓﻘـﺎ‬ ‫ﳍﺬﺍ ﺍﻟﻨﻈﺎﻡ‪.‬‬

‫‘‪@ @HoîmbiaI@êìuìÛa@ïa†Ûa@âbÄäÛa@H@TMV@I@ÝØ‬‬

‫‪ ÝØ’Ûa@ŞîÈ½a@âbÄäÛa@@TMQMV‬ﻳﻌﺪ ﺑﻌﺾ ﻣ‪‬ﺨﺘﺼ‪‬ﻲ ﺍﻟﺒﻠﻮﺭﺍﺕ ﺍﻟﻨﻈﺎﻡ ﺍﳌﻌﻴﲏ ﺍﻟﺸﻜﻞ ﻣﻦ ﻓﺼﻴﻠﺔ ﺍﻟﻨﻈـﺎﻡ‬ ‫ﺳﺪﺍﺳﻲ ﺍﻟﻮﺟﻮﻩ‪ ،‬ﺫﻟﻚ ﻷﻥ ﻛﻼ ﺍﻟﻨﻈﺎﻣﲔ ﳝﻜﻦ ﲢﺪﻳﺪﳘﺎ ﺑﺎﻟﻨﺴﺒﺔ ﺇﱃ ﻧﻔﺲ ﺍﶈﺎﻭﺭ‪ .‬ﻭﻟﻜﻦ ﻫﻨﺎﻙ ﻓـﺮﻕ‬ ‫ﻭﺍﺣﺪ ﺭﺋﻴﺴﻲ ﺑﻴﻨﻬﻤﺎ‪ .‬ﻓﺎﶈﻮﺭ ﺍﻟﻌﻤﻮﺩﻱ ﰲ ﺍﻟﺒﻠﻮﺭﺓ ﺍﳌﻌﻴﻨﻴﺔ ﺍﻟﺸﻜﻞ ﳏﻮﺭ ﺛﻼﺛﻲ ﺍﻟﺘﻨﺎﻇﺮ ﺑﻴﻨﻤﺎ ﰲ ﺍﻟﺒﻠﻮﺭﺓ‬ ‫ﺍﻟﺴﺪﺍﺳﻴﺔ ﺍﻟﺸﻜﻞ ﳏﻮﺭ ﺳﺪﺍﺳﻲ ﺍﻟﺘﻨﺎﻇﺮ‪ .‬ﻭﺃﺑﺴﻂ ﺑﻠﻮﺭﺓ ﰲ ﺍﻟﻨﻈﺎﻡ ﺍﳌﻌﻴﲏ ﺍﻟﺸﻜﻞ ﻫﻮ ﺍﻟﺒﻠـﻮﺭﺓ ﺍﻟـﱵ‬ ‫ﺗﺸﺘﻤﻞ ﻋﻠﻰ ﺳﺘﺔ ﻭﺟﻮﻩ ﻣﻌﻴﻨﻴﺔ ﻣﺘﺴﺎﻭﻳﺔ‪ ،‬ﳛﺘﻮﻱ ﻛﻞ ﻣﻨﻬﺎ ﻋﻠﻰ ﻣﺘﻮﺍﺯﻱ ﺃﺿـﻼﻉ‪ .‬ﺗﻨﺘﻤـﻲ ﺑﻠـﻮﺭﺍﺕ‬ ‫ﺍﻟﻜﻠﺴﻴﺖ ﻭﺍﻟﺪﻭﻟﻮﻣﻴﺖ ﻭﺍﻟﻜﻮﺍﺭﺗﺰ ﺇﱃ ﻫﺬﺍ ﺍﻟﻨﻈﺎﻡ‪.‬‬

‫‘‪@ @HëŠ½aI@ÝØ’Ûa@îÈ½a@âbÄäÛa@H@UMV@I@ÝØ‬‬

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‫‪ á@ öb;ÔÛa@ŞîÈ½a@âbÄäÛa@@UMQMV‬ﲤﺘﺎﺯ ﺍﳌﻌﻴﻨﻴﺔ ﺍﻟﻘﺎﺋﻤﺔ ﺑﺜﻼﺛﺔ ﳏﺎﻭﺭ ﻣﺘﻌﺎﻣﺪﺓ‪ ،‬ﻏﲑ ﻣﺘـﺴﺎﻭﻳﺔ ﺍﻷﻃـﻮﺍﻝ‪.‬‬ ‫ﻭﳝﺜﻞ ﺍﳌﻨﺸﻮﺭ ﺍﳌﻌﻴﲏ ﺍﻟﻘﺎﺋﻢ ﺫﻭ ﺍﳌﺴﺘﻄﻴﻼﺕ ﺍﻟﺜﻼﺛﺔ ﻏﲑ ﺍﳌﺘﺴﺎﻭﻳﺔ‪ ،‬ﺍﻟﱵ ﺗﺘﻼﻗﻰ ﰲ ﺯﻭﺍﻳﺎ ﻗﺎﺋﻤﺔ ﺃﺑـﺴﻂ‬ ‫ﺑﻠﻮﺭﺍﺕ ﻫﺬﺍ ﺍﻟﻨﻮﻉ‪ .‬ﻭﺗﺘﺒﻠﻮﺭ ﻭﺍﻟﺒﺎﺭﻳﺖ ﻭﺍﻟﺘﻮﺑﺎﺯ )ﺍﻟﻴﺎﻗﻮﺕ ﺍﻷﺻﻔﺮ( ﻭﻣﻌﺎﺩﻥ ﺃﺧﺮﻯ ﻭﻓﻘﹰﺎ ﳍﺬﺍ ﺍﻟﻨﻈﺎﻡ‪.‬‬

‫‘‪@ @Hoí‰bjÛaI@áöbÔÛa@óäîÈ½a@âbÄäÛa@H@VMV@I@ÝØ‬‬

‫@@‬ ‫‪ Ý@ ;î½a@Čð…byþa@âbÄäÛa@VMQMV‬ﻳﺘﻌﺎﻣﺪ ﳏﻮﺭﺍﻥ ﻣﻦ ﺍﶈﺎﻭﺭ ﺍﻟﺜﻼﺛﺔ ﰲ ﺍﻟﺒﻠﻮﺭﺍﺕ ﺃﺣﺎﺩﻳﺔ ﺍﳌﻴﻞ ﻭﳝﻴﻞ ﺍﻟﺜﺎﻟﺚ‬ ‫ﻋﻨﻬﻤﺎ‪ ،‬ﻭﳍﺎ ﺃﻃﻮﺍﻝ ﻣﺘﺒﺎﻳﻨﺔ‪ .‬ﻭﺗﺘﻤﺜﻞ ﺃﺑﺴﻂ ﺑﻠﻮﺭﺓ ﺃﺣﺎﺩﻳﺔ ﺍﳌﻴﻞ ﺑﻮﺟﻬﲔ ﳍﻤﺎ ﺷﻜﻞ ﺍﳌﻌﲔ ﺍﻟﻘﺎﺋﻢ ﻭﺑﺄﺭﺑﻌﺔ‬ ‫ﻣﺴﺘﻄﻴﻼﺕ ﺍﻟﻮﺟﻮﻩ‪ .‬ﺃﻣﺎ ﺍﻟﺴﻄﺢ ﺍﻟﻌﻠﻮﻱ ﻭﺍﻟﺴﻔﻠﻲ ﻓﻤﺎﺋﻼﻥ‪ .‬ﻭﻛﺜﲑ ﻣﻦ ﺍﳌﺮﻛﺒﺎﺕ ﺗﻨﺘﻤـﻲ ﺇﱃ ﻫـﺬﺍ‬ ‫ﺍﻟﻨﻈﺎﻡ‪.‬‬

‫‘‪@ @Hj¦aI@Ýî½a@Čð…byþa@âbÄäÛa@H@WMV@I@ÝØ‬‬ ‫@@‬

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‫‪ Ý@ ;î½a@ïqýrÛa@âbÄäÛa@WMQMV‬ﲣﺘﻠﻒ ﺃﻃﻮﺍﻝ ﺍﶈﺎﻭﺭ ﺍﻟﺜﻼﺛﺔ ﰲ ﺍﻟﺒﻠﻮﺭﺍﺕ ﺍﻟﺜﻼﺛﻴﺔ ﺍﳌﻴﻞ ﻭﻻﻳﺘﻌﺎﻣﺪ ﳏﻮﺭﺍﻥ‬ ‫ﻣﻨﻬﺎ؛ ﻟﺬﻟﻚ ﻛﺎﻧﺖ ﻭﺟﻮﻩ ﻫﺬﻩ ﺍﻟﺒﻠﻮﺭﺍﺕ ﳐﺘﻠﻔﺔ ﻭﻻ ﺗﺘﻼﻗﻰ ﰲ ﺯﺍﻭﻳﺔ ﻗﺎﺋﻤﺔ‪ .‬ﺗﺘﺸﻜﻞ ﻭﻓﻘﹰﺎ ﳍﺬﺍ ﺍﻟﻨﻈﺎﻡ‪،‬‬ ‫ﺑﻠﻮﺭﺍﺕ ﺳﻠﻴﻜﺎﺕ ﺍﻷﻟﻮﻣﻨﻴﻮﻡ ﻭﻗﻠﻴﻞ ﻣﻦ ﺍﳌﻌﺎﺩﻥ ﺍﻷﺧﺮﻯ‪.‬‬

‫‘‪@ @H‰bjÜÐÛaI@Ýî½a@ïqýrÛa@âbÄäÛa@H@XMV@I@ÝØ‬‬

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‫ ‬ ‫ ‬ ‫‪ 1-7‬‬

‫ﺃﻧﻪ ﻗﺪ ﰎ ﺍﻟﺸﺮﺡ ﻭﺍﻟﺘﻮﺿﻴﺢ ﰱ ﺍﻷﺑﻮﺍﺏ ﺍﻟﺴﺎﺑﻘﺔ ﻟﺘﻘﺴﻴﻢ ﻭﺗﺼﻨﻴﻒ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ‪ ،‬ﻭﻛﺬﻟﻚ ﺍﻟﺘﻌـﺮﻑ‬ ‫ﻋﻠﻰ ﲨﻴﻊ ﺧﻮﺍﺻﻬﺎ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻭﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﱴ ﲡﺮﻯ ﻟﺘﻌﻴﻴﻨﻬﺎ‪ .‬ﻟﺬﻟﻚ ﻓﺈﻧﻪ ﳚﺐ ﺃﻥ ﻧﺘﻌﺮﺽ ﺑﺎﻟﺸﺮﺡ‬ ‫ﻭﺍﻟﺘﻔﺼﻴﻞ ﻟﺒﻌﺾ ﳕﺎﺫﺝ ﻣﻦ ﺗﻠﻚ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﺍﻟﻜﺜﲑﺓ ﺍﻻﺳﺘﺨﺪﺍﻡ ﺣﺪﻳﺜﹰﺎ ﰱ ﳎﺎﻝ ﺻﻨﺎﻋﺔ ﺗﻜﻨﻮﻟﻮﺟﻴﺎ‬ ‫ﺍﳋﺮﺳﺎﻧﺔ ﻭﺍﻟﺒﻨﺎﺀ‪ .‬ﻭﻳﺮﺟﻊ ﺃﻳﻀﹰﺎ ﺍﺧﺘﻴﺎﺭ ﺗﻠﻚ ﺍﻟﻨﻤﺎﺫﺝ ﺇﱃ ﺗﻘﺴﻴﻢ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﺣـﺴﺐ ﺗـﺼﻨﻴﻔﺎ‪‬ﺎ‬ ‫ﺍﳌﺘﻌﺪﺩﺓ ﻣﻦ ﺣﻴﺚ ﻃﺒﻴﻌﺔ ﺗﺮﻛﻴﺒﻬﺎ ﻭﻣﺼﺪﺭ ﺍﳊﺼﻮﻝ ﻋﻠﻴﻬﺎ ﻭﺧﻮﺍﺻﻬﺎ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ‪ .‬ﻭﻣﻦ ﺃﻫﻢ ﺍﻟﻨﻤـﺎﺫﺝ‬ ‫ﺍﳌﺨﺘﺎﺭﺓ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﻫﻰ‪:‬‬ ‫ ‪@ @lb’þa‬‬‫ ‪@ @|îÜnÛa@†í†y‬‬‫ ‪@ @@paŠàîÛìjÛa‬‬‫ ‪@ @ÒbîÛþa‬‬‫‪@ @NÒbîÛþbi@êaìÔ½a@òíŠàîÛìjÛa@…aì½a@ -‬‬

‫ﻭﺳﻮﻑ ﻳﺘﻢ ﺷﺮﺡ ﻛﻞ ﻧﻮﻉ ﻣﻨﻬﺎ ﺑﺎﻟﺘﻔﺼﻴﻞ ﻛﻤﺎ ﻳﺄﺗﻰ‪.‬‬ ‫‪ 2-7‬‬

‫ﺗﻌﺪ ﺍﻷﺧﺸﺎﺏ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﳍﻨﺪﺳﻴﺔ ﺍﻟﻄﺒﻴﻌﻴﺔ ﺍﻟﻐﲑ ﻣﻌﺪﻧﻴﺔ ﻭﺍﻟﻨﺼﻒ ﻗﺼﻔﺔ‪ .‬ﻭﻳﻌﺪ ﺍﳋﺸﺐ ﺿﻤﻦ ﻃﺎﺋﻔـﺔ‬ ‫ﻣﻮﺍﺩ ﺍﻟﺒﻨﺎﺀ ﻭﺍﻟﺬﻯ ﻟﻪ ﺩﻭﺭ ﻫﺎﻡ ﻭﻓﻌﺎﻝ ﰱ ﺃﻋﻤﺎﻝ ﺍﻟﻌﻤﺎﺭﺓ ﻭﺍﻹﻧﺸﺎﺀﺍﺕ ﻣﻨﺬ ﻗﺪﱘ ﺍﻟﺰﻣﺎﻥ‪ ،‬ﻭﻣﺎﺯﺍﻟﺖ ﺣﱴ‬ ‫ﺍﻷﻥ ﺗﻌﺘﱪ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﳊﺪﻳﺜﺔ ﺍﻻﺳﺘﺨﺪﺍﻡ ﺣﻴﺚ ﺃ‪‬ﺎ ﺗﺴﺘﺨﺪﻡ ﺑﻨﻄﺎﻕ ﻭﺍﺳﻊ ﰱ ﺍﻷﻋﻤﺎﻝ ﺍﻹﻧـﺸﺎﺋﻴﺔ ﺇﱃ‬ ‫ﻛﺜﺮﺓ ¾‪ émaŒî‬ﻭﻫﻰ ﻛﺎﻵﺗﻰ‪:‬‬ ‫ ﺃﻧﻪ ﺧﻔﻴﻒ ﺍﻟﻮﺯﻥ‪.‬‬‫ ﺃﻥ ﻣﻘﺎﻭﻣﺘﻪ ﻟﻸﲪﺎﻝ ﻣﻨﺎﺳﺒﺔ ﻟﻠﻐﺮﺽ ﺍﳌﺴﺘﺨﺪﻣﺔ ﻣﻦ ﺃﺟﻠﻪ‪.‬‬‫ ﺃﻧﻪ ﻳﺴﻬﻞ ﲡﻬﻴﺰﻩ ﻭﺗﺸﻜﻴﻠﻪ ﻭﲡﻤﻴﻌﻪ ﻭﺗﺸﻐﻴﻠﻪ‪.‬‬‫ ﻳﺴﺘﺨﺪﻡ ﰱ ﺃﻋﻤﺎﻝ ﺍﻟﻌﺰﻝ ﺍﻟﺼﻮﺗﻰ ﻭﺍﳊﺮﺍﺭﻯ ﺑﻜﻔﺎﺀﺓ ﻋﺎﻟﻴﺔ‪.‬‬‫ ﺩﺭﺟﺔ ﲢﻤﻠﻪ ﻣﻊ ﺍﻟﺰﻣﻦ ﻋﺎﻟﻴﺔ ﻭﺇﺫﺍ ﺗﻮﻓﺮﺕ ﻟﻪ ﻃﺮﻕ ﺍﳊﻤﺎﻳﺔ ﺍﳌﻨﺎﺳﺒﺔ‪.‬‬‫‪١١٩‬‬


‫ﻭﻣﻊ ﻛﻞ ﻫﺬﻩ ﺍﳌﻤﻴﺰﺍﺕ ﺍﻟﻌﺪﻳﺪﺓ ﻟﻸﺧﺸﺎﺏ ﺇﻻ ﺃﻥ ﻟﻪ ‪ lìîÈÛa@œÈi‬ﻭﺍﻟﱴ ﺗﺘﻠﺨﺺ ﻓﻴﻤﺎ ﻳﻠﻰ‪:‬‬ ‫‪-‬‬

‫ﺃﻧﻪ ﻳﺴﻬﻞ ﺗﺂﻛﻠﻪ ﻭﺗﺴﻮﺳﻪ ﻭﲢﻠﻠﻪ ﺑﻔﻌﻞ ﺍﻟﺒﻜﺘﺮﻳﺎ ﻭﺍﻟﺮﻃﻮﺑﺔ ﻭﺍﳊﺸﺮﺍﺕ‪.‬‬

‫ ﻟﻪ ﻗﺎﺑﻠﻴﺔ ﻋﺎﻟﻴﺔ ﻋﻠﻰ ﺍﻻﺣﺘﺮﺍﻕ‪.‬‬‫ ﻟﻪ ﻗﺎﺑﻠﻴﺔ ﻋﻠﻰ ﺍﻻﻧﻜﻤﺎﺵ‪.‬‬‫‪@ @lb’þa@pbãìØß@QMRMW‬‬ ‫ﻣﻜﻮﻧﺎﺕ ﺍﳋﺸﺐ ﺍﳉﺎﻑ ﺑﺼﻔﺔ ﻋﺎﻣﺔ ﻭﺭﺋﻴﺴﻴﺔ ﺗﺘﻜﻮﻥ ﻣﻦ ﺍﻟﺴﻠﻴﻠﻮﺯ ﻛﻤﺎﺩﺓ ﺃﺳﺎﺳـﻴﺔ ﺑﻨـﺴﺒﺔ ﺣـﻮﺍﱃ‬ ‫‪ ،%٦٠‬ﻭﻣﺎﺩﺓ ﺍﻟﻠﻴﻨﲔ ﺑﻨﺴﺒﺔ ﺣﻮﺍﱃ ‪ ،%٢٨‬ﻭﻣﻮﺍﺩ ﺁﺧﺮﻯ ﺳﻜﺮﻳﺔ ﻭﻣﺘﻨﻮﻋﺔ ﺑﻨﺴﺒﺔ ﺣـﻮﺍﱃ ‪.%١٢‬‬ ‫ﻭﻋﻤﻮﻣﺎ ﻓﺈﻥ ﺍﻷﺷﺠﺎﺭ ﻭﻫﻰ ﺍﳌﺼﺪﺭ ﺍﻷﺳﺎﺳﻰ ﻹﻧﺘﺎﺝ ﺍﻷﺧﺸﺎﺏ ﻭﺍﻟﱴ ﲢﺘﻮﻯ ﻋﻠﻰ ﻛـﻞ ﻣﻜﻮﻧﺎﺗـﻪ‪،‬‬ ‫ﻭﺗﻠﻚ ﺍﻷﺷﺠﺎﺭ ﺗﻨﻤﻮ ﺑﺈﻧﻘﺴﺎﻡ ﺍﳋﻼﻳﺎ ﰱ ﺍﻹﲡﺎﻩ ﺍﻟﻌﺮﺿﻰ ﻣﻜﻮﻧﻪ ﺣﻠﻘﺎﺕ ﺗﺰﻳـﺪ ﻣـﻦ ﲰـﻚ ﺟـﺬﻉ‬ ‫ﺍﻟﺸﺠﺮﺓ‪ ،‬ﻭﻛﺬﻟﻚ ﺃﻳﻀﺎ ﺗﻨﻘﺴﻢ ﰱ ﺍﻹﲡﺎﻩ ﺍﻟﻄﻮﱃ‪ .‬ﻭﻋﻤﻮﻣﺎ ﺗﺘﻜﻮﻥ ﺍﳊﻠﻘﺔ ﰱ ﻋﺎﻡ ﻛﺎﻣﻞ ﻭﻟﺬﻟﻚ ﲰﻴﺖ‬ ‫ﺑﺎﳊﻠﻘﺎﺕ ﺍﻟﺴﻨﻮﻳﺔ‪.‬‬ ‫‪@ @Zlb’þa@Éîä–m@ÝyaŠß@RMRMW‬‬ ‫ﲤﺮ ﺻﻨﺎﻋﺔ ﺍﻷﺧﺸﺎﺏ ﲟﺮﺣﻠﺘﲔ ﺃﺳﺎﺳﻴﺘﻨﲔ ﻭﳘﺎ ﺍﻟﺘﻘﻄﻴﻊ ﻭﺍﻟﺘﺠﻔﻴﻒ‪ ،‬ﻭﻗﺪ ﳝﺮ ﲟﺮﺣﻠﺔ ﺛﺎﻟﺜﺔ ﻭﻫﻰ ﻭﻗﺎﻳـﺔ‬ ‫ﺍﳋﺸﺐ ﻭﺣﻔﻈﻪ ﺇﺫﺍ ﺇﺣﺘﺠﻨﺎ ﻟﺬﻟﻚ‪ .‬ﻭﺗﻠﻚ ﺍﳌﺮﺍﺣﻞ ﺑﺎﻟﺘﺮﺗﻴﺐ ﻫﻰ‪:‬‬

‫)‪ (1‬‬ ‫ﻳﺘﻢ ﺗﻘﻄﻴﻊ ﺍﻷﺷﺠﺎﺭ ﺃﻭﻻ‪ ،‬ﰒ ﺗﻮﺿﻊ ﰱ ﻗﻨﻮﺍﺕ ﻣﺎﺋﻴﺔ ﻟﺘﺨﻔﻴﻒ ﻭﺇﺯﺍﻟﺔ ﺍﻟﻌﺼﺎﺭﺓ ﻣﻨﻬﺎ‪ ،‬ﰒ ﺗﻘﻄﻊ ﺍﻟﻜﺘـﻞ‬ ‫ﺍﳋﺸﺒﻴﺔ ﻣﻦ ﺗﻠﻚ ﺍﻷﺷﺠﺎﺭ ﻭﻫﻰ ﲝﺎﻟﺘﻬﺎ ﺍﳌﺒﺘﻠﺔ ﺑﻌﺪﺓ ﻃﺮﻕ ﳐﺘﻠﻔﺔ ﻭﺫﻟﻚ ﺑﺎﻟﺸﻜﻞ ﻭﺍﻷﺑﻌـﺎﺩ ﻭﺍﻟﻐـﺮﺽ‬ ‫ﺍﳌﺴﺘﻌﻤﻠﺔ ﻫﺬﻩ ﺍﻷﺧﺸﺎﺏ ﻣﻦ ﺃﺟﻠﻪ‪.‬‬

‫)‪: (2‬‬ ‫ﺍﳌﻘﺼﻮﺩ ﻣﻦ ﲡﻔﻴﻒ ﺍﻷﺧﺸﺎﺏ ﻫﻮ ﺗﻘﻠﻴﻞ ﺇﻧﻜﻤﺎﺵ ﺍﳋﺸﺐ ﰱ ﺣﺎﻟﺘﻪ ﺍﳌﺒﺘﻠﻪ ﻭﺍﻟﺬﻯ ﻳـﺴﻤﻰ ﺍﳋـﺸﺐ‬ ‫ﺍﻷﺧﻀﺮ‪ ،‬ﻭﻋﻤﻮﻣﺎ ﻳﻜﻮﻥ ﺍﻟﺘﺠﻔﻴﻒ ﻟﻸﺧﺸﺎﺏ ﺑﺈﺣﺪﻯ ﺍﻟﻄﺮﻕ ﺍﻵﺗﻴﺔ‪:‬‬ ‫• ﺍﻟﺘﺠﻔﻴﻒ ﺍﻟﻄﺒﻴﻌﻰ‪:‬‬ ‫ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺘﺠﻔﻴﻒ ﻳﺘﻢ ﰱ ﺍﳍﻮﺍﺀ ﺍﻟﻄﻠﻖ ﺣﻴﺚ ﺗﺮﺹ ﺍﻷﻟﻮﺍﺡ ﺍﳌﺒﺘﻠﺔ ﺍﳋﻀﺮﺍﺀ ﰱ ﺻﻔﻮﻑ ﺑﺘﺮﺗﻴﺐ‬ ‫ﻣﻨﺘﻈﻢ ﲝﻴﺚ ﻳﻜﻮﻥ ﺑﻴﻨﻬﻤﺎ ﻓﻮﺍﺻﻞ ﺗﺴﻤﺢ ﺑﺘﺨﻠﻞ ﻭﻣﺮﻭﺭ ﺍﳍﻮﺍﺀ ﺑﻜﻞ ﺳﻬﻮﻟﺔ ﺧﻼﳍﺎ ﻭﻓﻴﻤﺎ ﺑﻴﻨـﻬﺎ‪ .‬ﻭﺫﺩ‬ ‫ﺗﺼﻞ ﺇﱃ ﲡﻔﻴﻒ ﻃﺒﻴﻌﻰ ﻟﻠﺨﺸﺐ ﻭﺑﻪ ﺣﻮﺍﱃ ‪ %٢٠‬ﺭﻃﻮﺑﺔ ﰱ ﻣﺪﺓ ﺗﺘﺮﺍﻭﺡ ﻣﺎ ﺑﲔ ‪ ٤٠‬ﺇﱃ ‪ ٩٠‬ﻳﻮﻡ‪.‬‬ ‫‪١٢٠‬‬


‫• ﺍﻟﺘﺠﻔﻴﻒ ﺍﻟﺼﻨﺎﻋﻰ‪:‬‬ ‫ﻳﺘﻢ ﺍﻟﺘﺠﻔﻴﻒ ﺍﻟﺼﻨﺎﻋﻰ ﰱ ﺃﻓﺮﺍﻥ ﺧﺎﺻﺔ ﻟﺬﻟﻚ ﺣﻴﺚ ﺗﺮﺹ ﺍﻷﻟﻮﺍﺡ ﺍﳋﺸﺒﻴﺔ ﺍﳌﻄﻠﻮﺏ ﲡﻔﻴﻔﻬﺎ ﺩﺍﺧـﻞ‬ ‫ﻏﺮﻑ ﺧﺎﺻﺔ ﳍﺎ ﺩﺭﺟﺎﺕ ﺣﺮﺍﺭﺓ ﻭﺭﻃﻮﺑﺔ ﻣﻌﻴﻨﺔ‪ ،‬ﻭﻳﺘﻢ ﺍﻟﺘﺠﻔﻴﻒ ﻟﻸﺧﺸﺎﺏ ﻭﺑﻪ ﺭﻃﻮﺑﺔ ﻓﻘـﻂ ﺣـﻮﺍﱃ‬ ‫‪ %٦‬ﰱ ﻣﺪﺓ ﺗﺘﺮﺍﻭﺡ ﻣﻦ ‪ ٣‬ﺃﻳﺎﻡ ﺇﱃ ‪ ١٢‬ﻳﻮﻡ ﻃﺒﻘﺎ ﻟﻨﻮﻉ ﻭﺣﺎﻟﺔ ﻭﻣﻮﺻﻔﺎﺕ ﺍﳋﺸﺐ ﺍﳌﺴﺘﺨﺪﻡ‪.‬‬ ‫• ﺍﻟﺘﺠﻔﻴﻒ ﺍﻟﻄﺒﻴﻌﻰ ﻭﺍﻟﺼﻨﺎﻋﻰ ) ﺍﻟﺘﺠﻔﻴﻒ ﺍﳌﺸﺘﺮﻙ(‪:‬‬ ‫ﻭﻫﻮ ﺍﻟﺘﺠﻔﻴﻒ ﺍﻟﻄﺒﻴﻌﻰ ﺃﻭ ﹰﻻ ﻟﻔﺘﺮﻩ ﻣﻌﻴﻨﺔ ﰱ ﺍﳍﻮﺍﺀ ﺍﻟﻄﻠﻖ ﻳﻌﻘﺒﻬﺎ ﻓﺘﺮﺓ ﺁﺧﺮﻯ ﻣﻦ ﺍﻟﺘﺠﻔﻴﻒ ﺍﻟـﺼﻨﺎﻋﻰ‪،‬‬ ‫ﻭﺗﻠﻚ ﺍﻟﻄﺮﻳﻘﺔ ﲡﻤﻊ ﺑﲔ ﳑﻴﺰﺍﺕ ﺍﻟﺘﺠﻔﻴﻒ ﺍﻟﻄﺒﻴﻌﻰ ﻭﺍﻟﺘﺠﻔﻴﻒ ﺍﻟﺼﻨﺎﻋﻰ‪.‬‬

‫‪ ! "#! -3‬‬ ‫ﺍﳌﻘﺼﻮﺩ ﺍﻷﺧﺸﺎﺏ ﻫﻮ ﺍﶈﺎﻓﻈﺔ ﻋﻠﻴﻪ ﻣﻦ ﲣﻠﻞ ﺍﻟﺮﻃﻮﺑﺔ ﺇﻟﻴﻪ ﺃﻭ ﺳﻬﻮﻟﺔ ﺍﺳﺘﺨﺪﺍﻣﻪ ﻛﻤـﺴﻜﻦ ﻭﻣﺄﻛـﻞ‬ ‫ﻟﻠﺒﻜﺘﺮﻳﺎ ﻭﺍﳊﺸﺮﺍﺕ‪ .‬ﻭﻗﺪ ﺗﺴﺘﺨﺪﻡ ﻣﻮﺍﺩ ﻛﺜﲑﺓ ﻭﻣﺘﻌﺪﺩﺓ ﺑﻐﺮﺽ ﲪﺎﻳﺔ ﻭﻭﻗﺎﻳﺔ ﺍﻷﺧﺸﺎﺏ‪ ،‬ﻭﻫﺬﻩ ﺍﳌﻮﺍﺩ‬ ‫ﺇﻣﺎ ﻣﻮﺍﺩ ﻛﻴﻤﻴﺎﺋﻴﺔ‪ .‬ﻭﻣﻨﻬﺎ ﳏﺎﻟﻴﻞ ﺳﺎﺋﻠﺔ ﻣﺎﺋﻴﺔ ﻣﺜﻞ ﻛﻠﻮﺭﻳﺪ ﺍﻟﺰﻧﻚ ﻭﻓﻠﻮﺭﻳﺪ ﺍﻟﺼﻮﺩﻳﻮﻡ ﻭﻏﲑﻫﺎ‪ ،‬ﻭﻣﻨـﻬﺎ‬ ‫ﺃﻳﻀﺎ ﳏﺎﻟﻴﻞ ﻃﻴﺎﺭﻩ ﻣﺜﻞ ﺍﻟﻔﻴﻨﻮﻝ ﻭﺍﻟﻨﺎﻓﺘﺎﻩ ﻭﻏﲑﻫﺎ‪ .‬ﻭﻣﻦ ﻣﻮﺍﺩ ﺍﻟﻮﻗﺎﻳﺔ ﺃﻳﻀﺎ ﺍﳌﻮﺍﺩ ﺍﻟـﺼﻤﻐﻴﺔ ﺃﻭ ﻭﻗﺎﻳـﺔ‬ ‫ﺍﻷﺧﺸﺎﺏ ﺑﺎﳌﻮﺍﺩ ﻭﺳﺎﻟﻔﺔ ﺍﻟﺬﻛﺮ ﺑﺎﻟﻄﺮﻕ ﺍﻵﺗﻴﺔ‪:‬‬ ‫• ﺑﻐﻤﺮ ﺍﳋﺸﺐ ﰱ ﺍﳌﻮﺍﺩ ﺍﳌﺬﻛﻮﺭﺓ ﺍﻟﻘﺘﺮﺓ ﺍﳌﻨﺎﺳﺒﺔ ﻟﺘﺸﺒﻌﻪ‪.‬‬ ‫• ﺣﻘﻦ ﺍﳋﺸﺐ ﲟﻮﺍﺩ ﺍﻟﻮﻗﺎﻳﺔ ﺍﳌﻄﻠﻮﺑﺔ ﲢﺖ ﺿﻐﻂ ﻣﻌﲔ‪.‬‬ ‫• ﻃﻼﺀ ﺍﳋﺸﺐ ﺑﺎﻟﻔﺮﺷﺔ ﺍﻟﻌﺎﺩﻳﺔ ﻟﻠﺪﻫﺎﻧﺎﺕ‪.‬‬ ‫• ﺭﺵ ﺍﳋﺸﺐ ﲟﺎﻛﻴﻨﺔ ﻣﻌﻴﻨﺔ ﲤﻸ ﲟﺎﺩﺓ ﺍﻟﻮﻗﺎﻳﺔ ﻭﺗﺮﺵ ﺭﺫﺍﺫﹰﺍ ﻋﻠﻰ ﺍﳋﺸﺐ ﺣﱴ ﻭﻗﺎﻳﺘﻪ‪.‬‬ ‫‪@ @lb’þa@Êaìãc@SMRMW‬‬ ‫ﺃﻧﻮﺍﻉ ﺍﻷﺧﺸﺎﺏ ﻛﺜﲑﺓ ﻭﻣﺘﻌﺪﺩﺓ‪ ،‬ﻭﺗﺘﻨﻮﻉ ﺍﻷﺧﺸﺎﺏ ﻃﺒﻘﺎ ﳌﺼﺎﺩﺭﻫﺎ ﺍﻟﻄﺒﻴﻌﻴﺔ ﻭﻣﺼﺎﺩﺭ ﺍﳊﺼﻮﻝ ﻋﻠﻴﻬﺎ‬ ‫ﻭﲣﺘﻠﻒ ﻛﺬﻟﻚ ﻃﺒﻘﺎ ﻟﺸﻜﻞ ﺃﻟﻴﺎﻓﻬﺎ ﻭﻟﻮ‪‬ﺎ ﻭﺧﻮﺍﺻﻬﺎ ﺍﻟﻄﺒﻴﻌﻴﺔ ﻭﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ‪ .‬ﻭﻗﺪ ﲣﺘﻠـﻒ ﺩﺭﺟـﺎﺕ‬ ‫ﺍﺳﺘﺨﺪﺍﻡ ﺍﳋﺸﺐ ﺗﺒﻌﺎ ﳌﺪﻯ ﺍﻟﻌﻴﻮﺏ ﻭﺩﺭﺟﺔ ﺍﳉﻮﺩﺓ ﺍﳌﻮﺟﻮﺩﺓ ﺑﻪ ﻭﺫﻟﻚ ﻟﻠﻨﻮﻉ ﺍﻟﻮﺍﺣﺪ ﻣﻨـﻪ‪ .‬ﻭﻗـﺪ‬ ‫ﺗﺘﻨﻮﻉ ﺃﺷﻜﺎﻝ ﻭﺃﺑﻌﺎﺩ ﺍﳋﺸﺐ ﺍﳌﻨﺘﺞ ﻓﻤﻨﻪ ﻣﻦ ﻳﻘﻄﻊ ﻭ ﳚﻬﺰ ﺑﺄﺑﻌﺎﺩ ﻣﻌﻴﻨﺔ ﻗﻴﺎﺳﻴﺔ ﻣﻄﻠﻮﺑﺔ ﻋﻠـﻰ ﻫﻴﺌـﺔ‬ ‫ﺃﻟﻮﺍﺡ ﻃﻮﻟﻴﺔ ﺃﻭ ﺃﻋﻤﺪﺓ ﻣﺴﺘﻄﻴﻠﺔ ﺃﻭ ﻣﺮﺑﻌﺔ ﺍﳌﻘﻄﻊ ﻟﺬﻟﻚ ﻓﺈﻧﻪ ﻳﺴﻬﻞ ﻗﻴﺎﺳﻪ ﺑﺎﳌﺘﺮ ﺍﻟﻄﻮﱃ ﻣﺜﻞ ﺍﳋـﺸﺐ‬ ‫ﺍﻷﺑﻴﺾ ﻭﺍﳋﺸﺐ ﺍﳌﻮﺳﻜﻰ‪ ،‬ﻭﻣﻨﻪ ﻣﻦ ﻳﻜﻮﻥ ﻛﺘﻞ ﻻ ﳝﻜﻦ ﻗﻄﻌﻪ ﻭﲡﻬﻴﺰﻩ ﺑﺄﺑﻌﺎﺩ ﻗﻴﺎﺳﻴﺔ ﻣﻌﻴﻨـﺔ ﻓﺈﻧـﻪ‬ ‫ﻳﻘﺎﺱ ﺑﺎﳌﺘﺮ ﺍﳌﻜﻌﺐ ﻣﺜﻞ ﺍﳋﺸﺐ ﺍﻟﺰﺍﻥ ﻭﺍﳋﺸﺐ ﺍﻟﻘﺮﻭ‪ ،‬ﻭﻟﻜﻦ ﻋﻤﻮﻣﺎ ﻣﻌﻈﻢ ﺃﻧﻮﺍﻉ ﺍﻷﺧﺸﺎﺏ ﺗﻘـﺎﺱ‬ ‫ﺑﺎﳌﺘﺮ ﺍﳌﻜﻌﺐ‪ ،‬ﻣﺎﻋﺪﺍ ﺑﻌﺾ ﺍﻷﻧﻮﺍﻉ ﺍﻟﱴ ﻳﺪﺧﻞ ﰱ ﺗﺼﻨﻴﻌﻬﺎ ﺍﻷﺧﺸﺎﺏ ﻣﺜﻞ ﺍﳋﺸﺐ ﺍﳌﻀﻐﻮﻁ‬ ‫‪١٢١‬‬


‫ﻭﺍﳋﺸﺐ ﺍﳊﺒﻴﱯ ﻭﺍﻷﺑﻠﻜﺎﺝ ﻭﺍﻟﻘﺸﺮﺓ ﻓﺈ‪‬ﺎ ﺗﻘﺎﺱ ﺑﺎﻟﻌﺪﺩ ) ﺑﺎﻟﻠﻮﺡ(‪ .‬ﻭﻣﻦ ﺃﻫـﻢ ﺃﻧـﻮﺍﻉ ﺍﻷﺧـﺸﺎﺏ‬ ‫ﺍﳌﺘﺨﺪﻣﺔ ﻫﻰ‪:‬‬ ‫•‬

‫ﺍﳋﺸﺐ ﺍﻷﺑﻴﺾ‬

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‫ﺍﳋﺸﺐ ﺍﳌﻮﺳﻜﻰ )ﺍﻟﺼﻨﻮﺑﺮﻯ(‬

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‫ﺍﳋﺸﺐ ﺍﻟﻌﺰﻳﺰﻯ‬

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‫ﺍﳋﺸﺐ ﺍﻟﺰﺍﻥ‬

‫‪Beech‬‬

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‫ﺍﳋﺸﺐ ﺍﻷﺭﻭ‬

‫‪Oak‬‬

‫‪Spruee‬‬

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‫ﺍﳋﺸﺐ‬

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‫ﺍﳋﺸﺐ ﺍﻟﺒﻠﻮﻁ‬

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‫ﺍﳋﺸﺐ ﺍﳉﻮﺯ‬

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‫ﺍﳋﺸﺐ ﺍﻷﺑﻨﻮﺱ‬

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‫ﺍﳋﺸﺐ ﺍﻷﺭﺯ‬

‫•‬

‫ﺍﳋﺸﺐ ﺍﻟﺴﺮﻭ‬

‫‪Pitch Pines‬‬

‫ﺍﳌﺎﻫﻮﺟﻴﲎ ‪Mahogany‬‬ ‫‪Ash‬‬

‫‪Walnut‬‬ ‫‪Ebony‬‬

‫‪Cedar‬‬ ‫‪Cypress‬‬

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‫ﺍﳋﺸﺐ‬

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‫ﺍﳋﺸﺐ ﺍﳌﲑﺍﻧﱴ‬

‫•‬

‫ﺍﳋﺸﺐ ﺍﳌﺎﻛﻮﺭﻯ‬

‫‪Makore‬‬

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‫ﺍﳋﺸﺐ ﺍﻟﺴﺎﺑﻴﻠﻰ‬

‫‪Sapale‬‬

‫•‬

‫ﺍﳋﺸﺐ ﺍﻟﺒﻮﺗﻴﻠﻰ )ﺍﻟﺴﻴﺒﻮ(‬

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‫ﺍﳋﺸﺐ ﺍﻻﺩﳚﻮ‬

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‫ﺍﳋﺸﺐ ﺍﻻﻛﻮﻣﻴﺔ‬

‫•‬

‫ﺍﳋﺸﺐ ﺍﻟﺘﻴﻚ‬

‫•‬

‫ﺍﳋﺸﺐ ﺍﻟﻜﺴﻴﺒﻮ‬

‫‪Candollei‬‬

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‫ﺍﳋﺸﺐ ﺍﻟﺒﻮﺛﺠﺒﺎ‬

‫‪Tessmani‬‬

‫•‬

‫ﺍﳋﺸﺐ‬

‫‪Pines‬‬

‫ﺍﳉﻮﺍﺭﻳﺎ ‪Guarea‬‬ ‫‪Meranti‬‬

‫‪Utile‬‬

‫‪Idigdo‬‬ ‫‪Okoume‬‬

‫‪Teak‬‬

‫ﺍﻟﺴﻴﻜﻮﻣﻮﺭ ‪Sycamore‬‬

‫‪١٢٢‬‬


‫ ﻭﻗﺪ ﺗﺪﺧﻞ ﺗﻠﻚ ﺍﻷﻧﻮﺍﻉ ﺍﳌﺨﺘﻠﻔﺔ ﻣﻦ ﻫﺬﻩ ﺍﻷﺧﺸﺎﺏ ﰱ ﺻﻨﺎﻋﺔ ﺃﻧﻮﺍﻉ ﺃﺧﺮﻯ ﻣـﺼﻨﻌﺔ ﺑﻄـﺮﻕ‬‫ﻋﺪﻳﺪﺓ ﻷﻏﺮﺍﺽ ﳐﺘﻠﻔﺔ ﻭﻣﻦ ﺃﻣﺜﻠﺔ ﻫﺬﻩ ﺍﻷﻧﻮﺍﻉ ﺍﳌﺼﻨﻌﺔ ﻫﻰ ﺍﳋﺸﺐ ﺍﳌﻀﻐﻮﻁ ﻭﺍﳋﺸﺐ ﺍﳊﺒـﻴﱯ‬ ‫ﻭﺍﳋﺸﺐ ﺍﻟﺮﻗﺎﺋﻘﻰ )ﺍﻷﺑﻠﻜﺎﺝ( ﻭﺍﳋﺸﺐ ﺍﻟﻘﺸﺮﺓ ﻭﺳﻮﻑ ﻳﺘﻢ ﺍﻟﺘﻌﺮﻳﻒ ﻋﻠﻰ ﻛﻞ ﻧﻮﻉ ﻋﻠﻰ ﺣﺪﺓ‬ ‫*‬

‫ )‪.(Fibre Hard Board‬‬

‫ﻫﻰ ﺃﻟﻮﺍﺡ ﻣﺼﻨﻌﺔ ﻣﻦ ﺍﻷﻟﻴﺎﻑ ﺍﻟﻨﺒﺎﺗﻴﺔ ﺃﻭ ﺃﻯ ﻣﺎﺩﺓ ﳉﻨﻮﺳﻠﻴﻠﻮﺯﻳﺔ ﺃﺧﺮﻯ ﻣﺜﻞ ﻗﺸﺮ ﺍﻷﺭﺯ ﺃﻭ ﺍﻟﺒﻮﺹ ﺃﻭ‬ ‫ﻛﺴﺮ ﺃﻯ ﻧﻮﻉ ﻣﻦ ﺍﻷﺧﺸﺎﺏ‪ ،‬ﻣﻊ ﺭﺑﻄﻬﺎ ﺑﺎﻟﺮﺍﺗﻨﺠﺎﺕ ﺍﻟﺼﻨﺎﻋﻴﺔ ﻣﺜﻞ ﺍﻟﻔﻴﻨﻮﻝ ﻓﻮﺭﻣﺎﻟﺪﻫﻴـﺪ ﺑﺎﻟﻄﺮﻳﻘـﺔ‬ ‫ﺍﻟﺮﻃﺒﺔ ﻭﺇﺿﺎﻓﺔ ﺃﻳﻀﺎ ﴰﻊ ﺑﺮﺍﻓﲔ‪ ،‬ﻭﻳﺘﻢ ﻛﺴﺒﻬﺎ ﲢﺖ ﺿﻐﻂ ﻣﺮﺗﻔﻊ ﻭﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﻋﺎﻟﻴﺔ‪ ،‬ﰒ ﻳﺘﻢ ﺗﺼﻠﺪ‬ ‫ﺍﻷﻟﻮﺍﺡ ﺑﻌﺪ ﺫﻟﻚ ﰱ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﻭﺭﻃﻮﺑﺔ ﻣﺘﻨﺎﺳﺒﺘﲔ ﻋﻠﻰ ﺃﻥ ﺗﻜﻮﻥ ﺍﻷﻟﻮﺍﺡ ﺧﺎﻟﻴﺔ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﻟﻐﺮﻳﺒﺔ‬ ‫ﺍﻟﻀﺎﺭﺓ‪.‬‬ ‫*‬

‫ ‪.( Particle Bozrd) !"#‬‬

‫ﻫﻮ ﺃﻟﻮﺍﺡ ﻣﺼﻨﻌﺔ ﲢﺖ ﺿﻐﻂ ﻣﺮﺗﻔﻊ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﻋﺎﻟﻴﺔ ﻣﻦ ﺃﻯ ﻣﺎﺩﺓ ﳉﻨﻮﺳﻠﻴﻮﻟﻮﺯﻳﺔ ﻣﺜﻞ ﺣـﺬﺍﺫﺍﺕ‬ ‫ﺍﳋﺸﺐ ﺃﻭ ﺳﺎﺵ ﺍﻟﻜﺘﺎﻥ ﺃﻭ ﻣﺼﺎﺹ ﺍﻟﻘﺼﺐ ﺃﻭ ﻧﺸﺎﺭﺓ ﺍﳋﺸﺐ ﻣﻊ ﻣﺎﺩﺓ ﺭﺍﺗﻨﺠﻴﺔ ﺭﺍﺑﻄﺔ‪ ،‬ﻭﻗﺪ ﺗﻀﺎﻑ‬ ‫ﺑﻌﺾ ﺍﳌﻮﺍﺩ ﻣﺜﻞ ﴰﻊ ﺍﻟﱪﺍﻓﲔ ﻭﺫﻟﻚ ﻟﺘﺤﺴﲔ ﺑﻌﺾ ﺍﳋﻮﺍﺹ ﻣﺜﻞ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺘﺴﺮﺏ ﻭﺇﻣﺘﺼﺎﺹ ﺍﳌﺎﺀ‪.‬‬ ‫* ('&‪(*+, ) $%‬‬

‫)‪.(Plywood‬‬

‫ﻫﻮ ﻟﻮﺡ ﻣﻦ ﺍﳋﺸﺐ ﻳﺘﻜﻮﻥ ﻣﻦ ﳎﻤﻮﻋﺔ ﻣﻦ ﺍﻟﻄﺒﻘﺎﺕ ﺍﳌﺘﻤﺎﺳﻜﺔ ﻣﻊ ﺑﻌﻀﻬﺎ ﺃﻭ ﲨﻴﻌﻬﺎ ﻣـﻦ ﺃﻯ ﻧـﻮﻉ‬ ‫ﻣﻄﻠﻮﺏ ﻣﻦ ﺃﻧﻮﺍﻉ ﺍﳋﺸﺐ ﻭﺫﻟﻚ ﺑﺎﺳﺘﺨﺪﺍﻡ ﻣﺎﺩﺓ ﻏﺮﺍﺀ ﻻﺻﻘﺔ‪ ،‬ﻭﻋﺎﺩﺓ ﻣﺎ ﻳﻜﻮﻥ ﺇﲡـﺎﻩ ﺍﻷﻟﻴـﺎﻑ ﰱ‬ ‫ﺍﻟﻄﺒﻘﺎﺕ ﺍﳌﺘﺠﺎﻭﺭﺓ ﻣﺘﻌﺎﻣﺪﺍﹰ‪ ،‬ﻭﺗﻜﻮﻥ ﺍﻟﻄﺒﻘﺎﺕ ﺍﻟﺪﺍﺧﻠﻴﺔ ﻭﺍﳋﺎﺭﺟﻴﺔ ﻣﺘﻤﺎﺛﻠـﺔ ﻋﻠـﻰ ﺟﻬـﱴ ﺍﻟﻄﺒﻘـﺔ‬ ‫ﺍﻟﻮﺳﻄﻰ‪.‬‬ ‫ﻭﻣﻦ ﺍﻷﺑﻠﻜﺎﺝ ﺃﻧﻮﺍﻉ ﻛﺜﲑﺓ ﻭﻋﺪﻳﺪﺓ ﻭﻫﻰ‪:‬‬ ‫* ﺃﺑﻠﻜﺎﺝ ﺇﻧﺸﺎﺋﻰ‬

‫* ﺃﺑﻠﻜﺎﺝ ﺣﺸﻮ‬

‫* ﺃﺑﻠﻜﺎﺝ ﺧﺎﺹ‬

‫* ﺃﺑﻠﻜﺎﺝ ﺩﻳﻜﻮﺭ‬

‫* ﺃﺑﻠﻜﺎﺝ ﻗﺸﺮﺓ‬

‫* ﺃﺑﻠﻜﺎﺝ ﻣﺘﻌﺪﺩ ﺍﻟﻄﺒﻘﺎﺕ‬

‫* ﺃﺑﻠﻜﺎﺝ ﺑﻮﺻﻠﺔ ﻣﺎﺋﻠﺔ‬

‫* ﺃﺑﻠﻜﺎﺝ ﺑﻮﺻﻠﺔ ﻣﺼﺒﻌﺔ‬

‫* ﺃﺑﻠﻜﺎﺝ ﻏﲑ ﻣﺼﻨﻔﺮ‬

‫* ﺃﺑﻠﻜﺎﺝ ﺫﻭ ﺃﻟﻴﺎﻑ ﻃﻮﻟﻴﺔ‬

‫* ﺃﺑﻠﻜﺎﺝ ﺫﻭ ﺃﻟﻴﺎﻑ ﻋﺮﺿﻴﺔ‬

‫* ﺃﺑﻠﻜﺎﺝ ﻣﺘﺠﺎﻧﺲ‬

‫* ﺃﺑﻠﻜﺎﺝ ﺧﺸﻦ‬

‫* ﺃﺑﻠﻜﺎﺝ ﳐﻠﻂ‬

‫* ﺃﺑﻠﻜﺎﺝ ﻣﺮﻛﺐ‬

‫* ﺃﺑﻠﻜﺎﺝ ﻣﻄﺒﻮﻉ‬

‫* ﺃﺑﻠﻜﺎﺝ ﻣﻐﻠﻒ‬

‫* ﺃﺑﻠﻜﺎﺝ ﳑﺸﻂ‬

‫‪١٢٣‬‬


‫* ('‪:" .‬‬

‫ﻫﻰ ﺷﺮﳛﺔ ﺭﻗﻴﻘﺔ ﻣﻦ ﺍﳋﺸﺐ ﺗﺼﻨﻊ ﻣﻦ ﺃﻧﻮﺍﻉ ﳐﺘﻠﻔﺔ ﻣﻦ ﺍﻷﺧﺸﺎﺏ ﺑﻄﺮﻳﻘﺔ ﺍﻟﻜﺸﻂ ﳉﺬﻭﻉ ﺃﻭ ﺟﺬﻭﺭ‬ ‫ﺍﻷﺷﺠﺎﺭ‪ ،‬ﻭﺗﻮﺿﻊ ﺍﻟﻘﺸﺮﺓ ﻫﺬﻩ ﻋﻠﻰ ﺍﻷﺷﻄﺢ ﺍﳋﺎﺭﺟﻴﺔ ﻟﻠﻤﻨﺘﺠﺎﺕ ﺍﳋﺸﺒﻴﺔ‪ .‬ﻭﻣﻨﻬﺎ ﺃﻧـﻮﺍﻉ ﻋﺪﻳـﺪﺓ‬ ‫ﲣﺘﻠﻒ ﺑﺈﺧﺘﻼﻑ ﻧﻮﻉ ﺍﳋﺸﺐ ﺍﳌﺴﺘﺨﺪﻡ ﻭﻫﻰ‪:‬‬ ‫* ﺍﻟﻘﺸﺮﺓ ﺍﻟﺴﺎﺑﻴﻠﻰ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﳌﺎﻫﻮﺟﲎ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﻟﻴﺘﺎﻣﺎ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﻟﻜﻮﺳﻴﺒﻮ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﻟﺴﻴﻮ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﻟﺒﻮﻣﺜﺠﺎ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﳉﻮﺍﺭﻳﺎ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﳌﺎﻛﻮﺭﻯ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﻟﺒﻠﻮﻁ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﳉﻮﺯ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﻟﺰﺍﻥ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﻷﺭﻭ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﻟﺴﻴﻜﻮﻣﻮﺭ‬

‫* ﺍﻟﻘﺸﺮﺓ ﺍﻟﺘﻴﻚ‬

‫‪@ @Properties of Timber @lb’þa@ãì@TMRMW‬‬ ‫‪ -١‬ﺍﻟﻜﺜﺎﻓﺔ )‪ :(Density‬ﺗﻌﺘﱪ ﺍﻟﻜﺜﺎﻓﺔ ﻋﺎﻣﻞ ﻣﻬﻢ ﻟﻠﺤﻜﻢ ﻋﻠﻰ ﺟﻮﺩﺓ ﺍﳋﺸﺐ‪ ،‬ﻭﺣﻴﺚ ﺃﻥ ﺟـﻮﺩﺓ‬ ‫ﺍﳋﺸﺐ ﺗﺰﺩﺍﺩ ﺑﺰﻳﺎﺩﺓ ﻛﺜﺎﻓﺔ ﻭﺍﻟﻌﻜﺲ ﺻﺤﻴﺢ‪ .‬ﻭﻋﻤﻮﻣﺎ ﻛﺜﺎﻓﺔ ﺍﻷﺧﺸﺎﺏ ﺃﺧﻒ ﻣﻦ ﻛﺜﺎﻓﺔ ﺍﳌﺎﺀ‪ ،‬ﻭﻗـﺪ‬ ‫ﻳﺘﺮﻭﺍﺡ ﺍﻟﻮﺯﻥ ﺍﻟﻨﻮﻋﻰ ﻟﻠﺨﺸﺐ ﻣﺎ ﺑﲔ ‪ ٠,٩ – ٠,٣‬ﺣﺴﺐ ﻧﻮﻋﺎﳋﺸﺐ ﻭﻋﻤﺮ ﺍﻷﺷﺠﺎﺭ ﺍﳌﺼﻨﻊ ﻣﻨﻬﺎ‬ ‫ﺍﳋﺸﺐ ﻭﳏﺘﻮﻯ ﺍﻟﺮﻃﻮﺑﺔ ﺍﻟﺪﺍﺧﻠﻰ ‪‬ﺎ‬ ‫‪ -٢‬ﺍﻟﺮﻃﻮﺑﺔ )‪ :(Moisture‬ﻟﻠﺮﻃﻮﺑﺔ ﺗﺄﺛﲑ ﻓﻌﺎﻝ ﻋﻠﻰ ﻣﻘﺎﻭﻣﺔ ﺍﻷﺧﺸﺎﺏ ﻟﻸﲪﺎﻝ ﻟﺘﻨﺎﺳﺐ ﺍﻟﻌﻜﺲ ﻣﻊ‬ ‫ﺍﳌﻘﺎﻭﻣﺔ‪ ،‬ﻭﻛﺬﻟﻚ ﺗﺴﺎﻋﺪ ﻋﻠﻰ ﺳﺮﻋﺔ ﺗﻠﻒ ﺍﳋﺸﺐ ﺑﺎﻟﺘﺂﻛﻞ ﺑﺎﻟﺮﻃﻮﺑﺔ‪ .‬ﻭﻋﺎﺩﺓ ﳛﺘﻮﻯ ﺍﳋﺸﺐ ﻋﻠـﻰ‬ ‫ﺍﻟﺮﻃﻮﺑﺔ ﺧﻼﻝ ﺟﺪﺭﺍﻥ ﺧﻼﻳﺎ ﺍﳋﺸﺐ ﺍﻟﺪﺍﺧﻠﻴﺔ ﻭﺍﳋﺎﺭﺟﻴﺔ ‪ ،‬ﻭﺃﻳﻀﺎ ﺧﻼﻝ ﺍﻟﻔﺮﺍﻏﺎﺕ ﺍﻟﺪﺍﺧﻠﻴﺔ ﺑﺎﳋﻼﻳﺎ‬ ‫) ﺍﳌﺎﺀ ﺍﳊﺮ(‪ .‬ﻟﺬﻟﻚ ﻓﺈﻧﻪ ﳚﺐ ﻟﻠﺤﺼﻮﻝ ﻋﻠﻰ ﺧﺸﺐ ﻟﻪ ﺟﻮﺩﻩ ﻋﺎﻟﻴﺔ ﺃﻥ ﻳﺘﻢ ﲡﻔﻴﻒ ﺍﳋﺸﺐ ﺑـﺄﻋﻠﻰ‬ ‫ﻛﻔﺎﺀﺓ ﺍﻟﺮﻃﻮﺑﺔ ﺍﻟﱴ ﳚﺪ ﺃﻥ ﺍﳋﻼﻳﺎ ﻛﻠﻬﺎ ﻭﻟﻴﺲ ﻳﻌﺘﻤﺪ ﻋﻠﻰ ﺗﺒﺨﺮ ﺍﳌﺎﺀ ﺍﳊﺮ ﺃﻭ ﺑﻌﺾ ﻣﻦ ﺍﻟﺮﻃﻮﺑﺔ ﺍﻟـﱴ‬ ‫ﻋﻠﻰ ﺟﺪﺭﺍﻥ ﺍﳋﻼﻳﺎ‪ ،‬ﻭﺫﻟﻚ ﻷﳘﻴﺔ ﻃﺮﺩ ﺍﻟﺮﻃﻮﺑﺔ ﻣﻦ ﺍﳋﺸﺐ ﻭﻣﺘﺎﻧﺘﻪ‪.‬‬ ‫‪ -٣‬ﺍﳌﻘﺎﻭﻣﺔ )‪ :(Strength‬ﺇﻥ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻷﺳﺎﺳﻴﺔ ﻟﻠﺤﻜﻢ ﻋﻠﻰ ﺟﻮﺩﺓ ﻣﺘﺎﻧﺔ ﺍﻷﺧﺸﺎﺏ ﻫـﻰ ﻣﻘﺎﻭﻣـﺔ‬ ‫ﺍﻟﻀﻐﻂ ﻭﺫﻟﻚ ﰱ ﺇﲡﺎﻩ ﺍﻷﻟﻴﺎﻑ ﻟﻠﺨﺸﺎﺏ ﺃﻭ ﺍﻻﲡﺎﻩ ﺍﻟﻌﻤﻮﺩﻯ ﻋﻠﻴﻬﺎ ﻟﻜﻦ ﳚﺐ ﻣﻼﺣﻈﺔ ﺃﻥ ﺍﻷﺧﺸﺎﺏ‬ ‫ﺗﻘﺎﻭﻡ ﺑﺪﺭﺟﺔ ﻋﺎﻟﻴﺔ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﺸﺪ ﰱ ﺍﲡﺎﻩ ﺃﻟﻴﺎﻓﻬﺎ‪ ،‬ﺣﻴﺚ ﺃﻥ ﻣﻘﺎﻭﻣﺔ ﺍﻟـﺸﺪ ﻟﻸﺧـﺸﺎﺏ ﰱ ﺍﲡـﺎﻩ‬ ‫ﺍﻷﻟﻴﺎﻑ ﻗﺪ ﺗﺘﺮﺍﻭﺡ ﻣﺎﺑﲔ ‪ ٢٠٠٠ – ٧٠٠‬ﻛﺠﻢ‪/‬ﺳﻢ‪ ،٢‬ﻭﻟﻜﻦ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﰱ ﺍﻻﲡﺎﻩ ﺍﻟﻌﻤﻮﺩﻯ ﻋﻠﻰ‬ ‫ﺍﻷﻟﻴﺎﻑ ﺿﻌﻴﻔﺔ ﺟﺪﹰﺍ ﻧﺴﺒﻴﹰﺎ ﺇﺫﺍ ﻣﺎ ﻗﻮﺭﻧﺖ ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﻘﺺ ﺑﺈﺟﻬﺎﺩﺍﺕ ﺍﻻﳓﻨﺎﺀ ﳚﻌﻞ ﻣﻘﺎﻭﻣﺔ ﺍﳋـﺸﺐ‬ ‫‪١٢٤‬‬


‫ﺍﻟﻌﺎﻟﻴﺔ ﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﺸﺪ ﰱ ﺇﲡﺎﻩ ﺃﻟﻴﺎﻓﻪ ﻗﻠﻴﻞ ﺍﻟﻔﺎﺋﺪﺓ ﻣﻦ ﺗﻠﻚ ﺍﳌﻘﺎﻭﻣﺎﺕ‪ ،‬ﻭﻋﻠﻰ ﺫﻟﻚ ﻳﻜـﻮﻥ ﺍﳊﻜـﻢ‬ ‫ﺍﻷﺳﺎﺳﻰ ﻋﻠﻰ ﺍﳋﺸﺐ ﲟﻘﺎﻭﻣﺘﻪ ﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﻀﻐﻂ‪.‬‬ ‫‪ -٤‬ﺍﻟﻌﺰﻝ ﺍﳊﺮﺍﺭﻯ )‪ :(Heat Insulation‬ﻳﻌﺘﱪ ﺍﳋﺸﺐ ﻣﻦ ﺍﳌﻮﺍﺩ ﺫﺍﺕ ﺍﻟﻌﺰﻝ ﺍﳊﺮﺍﺭﻯ ﺍﳉﻴﺪ ﻭﻟﺬﺍ‬ ‫ﻓﺈﻧﻪ ﻳﺴﺘﺨﺪﻡ ﰱ ﺗﺒﻄﲔ ﺍﳊﻮﺍﺋﻂ ﺍﻟﺪﺍﺧﻠﻴﺔ ﻟﻠﺤﺠﺮﺍﺕ‪ ،‬ﻭﻣﻌﺎﻣﻞ ﺍﻟﺘﻮﺻﻴﻞ ﺍﳊﺮﺍﺭﻯ ﻟﻠﺨـﺸﺐ ﺣـﻮﺍﱃ‬ ‫‪ ٠,٩٦‬ﻭﻟﻜﻦ ﺍﻷﺧﺸﺎﺏ ﺳﺮﻳﻌﺔ ﺍﻻﺣﺘﺮﺍﻕ ﻭﺑﺎﻷﺧﺺ ﺍﻟﺘﺎﻡ ﺍﳉﻔﺎﻑ ﻣﻨﻬﺎ‪.‬‬ ‫‪ -٥‬ﺍﻟﻌﺰﻝ ﺍﻟﻜﻬﺮﺑﺎﺋﻰ )‪ :(Electrical Insulation‬ﺍﳋﺸﺐ ﺍﳉﺎﻑ ﻣﻦ ﺃﻫـﻢ ﺍﻟﻌـﻮﺍﺯﻝ ﺍﳉﻴـﺪﺓ‬ ‫ﻟﻠﻜﻬﺮﺑﺎﺀ‪ ،‬ﻭﻟﻜﻦ ﺗﻮﺍﺟﺪ ﺍﻟﺮﻃﻮﺑﺔ ﺑﻪ ﳚﻌﻠﻪ ﺟﻴﺪ ﺍﻟﺘﻮﺻﻴﻞ ﻟﻠﻜﻬﺮﺑﺎﺀ‪.‬‬ ‫‪@ @Methods Of Testing Timber@lb’þa@‰bîna@ÖŠ@UMRMW‬‬ ‫ﺗﺘﻀﻤﻦ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﳌﺼﺮﻳﺔ ﻃﺮﻕ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﻄﺒﻴﻌﻴﺔ ﻭﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻸﺧﺸﺎﺏ ﻟﻠﺤﻜﻢ ﻋﻠﻰ ﺧـﻮﺍﺹ‬ ‫ﺍﳋﺸﺐ ﻭﺍﻵﺗﻰ ﺑﻴﺎ‪‬ﺎ‪:‬‬ ‫‪ -١‬ﳏﺘﻮﻯ ﺍﻟﺮﻃﻮﺑﺔ‬ ‫‪ -٢‬ﺍﻻﻧﻀﻐﺎﻁ‬ ‫• ﰱ ﺍﲡﺎﻩ ﻣﻮﺍﺯﻯ ﻟﺘﺮﺗﻴﺐ ﺍﻷﻟﻴﺎﻑ‪.‬‬ ‫• ﰱ ﺍﲡﺎﻩ ﻋﻤﻮﺩﻯ ﻋﻠﻰ ﺗﺮﺗﻴﺐ ﺍﻷﻟﻴﺎﻑ‪.‬‬ ‫‪ -٣‬ﺍﻟﺸﺪ‬ ‫• ﰱ ﺍﲡﺎﻩ ﻣﻮﺍﺯﻯ ﻟﺘﺮﺗﻴﺐ ﺍﻷﻟﻴﺎﻑ‪.‬‬ ‫• ﰱ ﺍﲡﺎﻩ ﻋﻤﻮﺩﻯ ﻋﻠﻰ ﺗﺮﺗﻴﺐ ﺍﻷﻟﻴﺎﻑ‪.‬‬ ‫‪ -٤‬ﺍﻻﳓﻨﺎﺀ ) ﺍﺧﺘﺒﺎﺭ ﺍﻟﻜﻤﺮﺓ(‬ ‫‪ -٥‬ﺍﻟﺼﻼﺩﺓ‬ ‫‪ -٦‬ﺍﻟﻘﺺ‬ ‫‪ -٧‬ﺍﻟﺼﺪﻡ‬ ‫‪ -٨‬ﺍﻻﻧﻜﻤﺎﺵ ﺍﻟﻘﻄﺮﻯ ﻭﺍﳌﻤﺎﺱ‬ ‫‪ -٩‬ﺍﻟﺸﻘﻖ‬ ‫ﻭﻷﳘﻴﺔ ﺗﺄﺛﲑ ﺍﻟﺮﻃﻮﺑﺔ ﻭﻣﻘﺎﻭﻣﺔ ﺍﻟﻀﻐﻂ ﻟﻠﺤﻜﻢ ﻋﻠﻰ ﺟﻮﺩﺓ ﻭﻣﺘﺎﻧﺔ ﺍﳋﺸﺐ ﻓﺈﻧﻪ ﺳﻮﻑ ﻳﺘﻢ ﺳﺮﺩ ﻃﺮﻕ‬ ‫ﺍﺧﺘﻴﺎﺭ ﻫﺎﺗﲔ ﺍﳋﺎﺻﺘﲔ ﻓﻘﻂ ﻛﻤﺎ ﻳﻠﻰ‪:‬‬ ‫‪١٢٥‬‬


‫• ﳏﺘﻮﻯ ﺍﻟﺮﻃﻮﺑﺔ‬ ‫ ﲡﻬﺰ ﻭﺗﻘﻄﻊ ﻗﻄﻌﺔ ﻣﻦ ﺍﳋﺸﺐ ﻣﻦ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﺑﻌﺪ ﺇﺟﺮﺍﺀ ﺃﻯ ﺍﺧﺘﺒﺎﺭ ﻣﻴﻜﺎﻧﻴﻜﻰ ﻋﻠﻴﻬﺎ ﻣﺒﺎﺷـﺮﺓ‬‫ﲝﻴﺚ ﺗﻜﻮﻥ ﺍﻟﻌﻴﻨﺔ ﻋﻠﻰ ﻫﻴﺌﺔ ﺷﺮﳛﺔ ﻣﺴﺘﻌﺮﺿﺔ ﺑﺴﻤﻚ ﺣﻮﺍﱃ ‪٢٥‬ﺳﻢ ﺑﺎﻟﻘﺮﺏ ﻣﻦ ﻣﻨﻄﻘﺔ ﺍﻟﻜﺴﺮ‬ ‫ﻭﻋﻠﻰ ﻣﺴﺎﻓﺔ ﻻ ﺗﻘﻞ ﻋﻦ ﳎﻤﻮﻉ ﻛﻼ ﻣﻦ ﻋﻤﻖ ﻭﻋﺮﺽ ﺍﳌﻘﻄﻊ ﺍﳌﺴﺘﻌﺮﺽ ﻟﻌﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻣﻦ ﺃﺣﺪ‬ ‫ﻃﺮﻓﻴﻬﺎ‪.‬‬ ‫‪-‬‬

‫ﺗﻮﺯﻥ ﺍﻟﻌﻴﻨﺔ ﻭﻟﻴﻜﻦ ﻭﺯ‪‬ﺎ )ﻭ( ﻭﲡﻔﻒ ﰱ ﻓﺮﻥ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺗﻪ ﻣﻦ ‪ ١٥٠ – ١٠٠‬ﻡﻩ ﺣﱴ ﻳﺜﺒـﺖ‬ ‫ﻭﺯﻥ ﺍﻟﻌﻴﻨﺔ ﻭﻟﻴﻜﻦ )ﻭ‪.(١‬‬

‫ ﲢﺴﺐ ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﶈﺘﻮﻯ ﺍﻟﺮﻃﻮﺑﺔ ﻣﻦ ﺍﻟﻌﻼﻗﺔ ﺍﻵﺗﻴﺔ‪:‬‬‫ﻭ – ﻭ‪١‬‬ ‫ﻡ=‬ ‫ﻭ‪١‬‬

‫‪١٠٠ X‬‬

‫ﺣﻴﺚ ﺃﻥ‪:‬‬ ‫ﻭ‪ :‬ﻭﺯﻥ ﺍﻟﻌﻴﻨﺔ ﻗﺒﻞ ﺍﻟﺘﺠﻔﻴﻒ‪.‬‬ ‫ﻭ‪ :١‬ﻭﺯﻥ ﺍﻟﻌﻴﻨﺔ ﺑﻌﺪ ﺍﻟﺘﺠﻔﻴﻒ‪.‬‬ ‫ﻡ‪ :‬ﺍﻟﻨﺴﺒﺔ ﺍﳌﺌﻮﻳﺔ ﳊﻤﺘﻮﻯ ﺍﻟﺮﻃﻮﺑﺔ‪.‬‬ ‫ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻀﻐﻂ‬‫ﺗﻌﲔ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻀﻐﻂ ﻟﻸﺧﺸﺎﺏ ﰱ ﺍﻻﲡﺎﻩ ﺍﳌﻮﺍﺯﺍﻯ ﻟﺘﺮﺗﻴﺐ ﺍﻷﻟﻴﺎﻑ‪ ،‬ﻭﻋﻤﻮﻣﺎ ﻳﻜﻮﻥ ﺍﻟـﻀﻐﻂ ﻋﻠـﻰ‬ ‫ﺍﻟﻮﺟﻪ ﺍﻟﻘﻄﺮﻯ ﻟﻌﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ‪ ،‬ﻭﻳﺒﲔ ﺍﻟﺸﻜﻞ ﺍﲡﺎﻫﺎﺕ ﺍﺧﺘﺒﺎﺭ ﻋﻴﻨﺔ ﺍﳋﺸﺐ‪.‬‬ ‫ﺃ‪ -‬ﻣﻘﺎﻭﻣﺔ ﺍﻟﻀﻐﻂ ﰱ ﺍﲡﺎﻩ ﻣﻮﺍﺯﻯ ﻟﺘﺮﺗﻴﺐ ﺍﻷﻟﻴﺎﻑ‬ ‫* ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ‪ :‬ﺗﻜﻮﻥ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻠﻰ ﺷﻜﻞ ﻣﻨﺸﻮﺭ ﺃﺑﻌﺎﺩﻩ ﺃﻣﺎ ﺃﻥ ﺗﻜﻮﻥ‪:‬‬ ‫‪٢٠ × ٥ × ٥‬ﺳﻢ‬

‫ﺃﻭ‬

‫‪ ٦ × ٢ × ٢‬ﺳﻢ‬

‫ ﻣﻦ ﺍﻟﻀﺮﻭﺭﻯ ﺃﻥ ﺗﻜﻮﻥ ‪‬ﺎﻳﺘﺎ ﻗﻄﻌﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻧﺎﻋﻤﺔ ﻭﻣﺘﻮﺍﺯﻳﺔ ﻭﻋﻤﻮﺩﻳﺔ ﻋﻠﻰ ﳏﻮﺭ ﺍﻟﻌﻴﻨﺔ‪.‬‬‫‪ -‬ﻭﳚﺐ ﺃﻥ ﻻ ﺗﻘﻞ ﺩﻗﺔ ﻗﻴﺎﺱ ﺃﺑﻌﺎﺩ ﻋﻴﻨﺎﺕ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻦ ‪ %٠,٣ +‬ﻣﻦ ﺃﺑﻌﺎﺩﻫﺎ ﺍﻷﺻﻠﻴﺔ‪.‬‬

‫‪١٢٦‬‬


‫* ﻃﺮﻳﻘﺔ ﺍﻟﻌﻤﻞ‪:‬‬ ‫ﳚﺮﻯ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻠﻰ ﺃﻯ ﻋﻴﻨﺔ ﻗﻴﺎﺳﻴﺔ ﻣﻄﻠﻮﺑﺔ ﻣﻦ ﺍﻟﻌﻴﻨﺎﺕ ﺍﻟﺴﺎﺑﻘﺔ ﻭﺫﻟﻚ ﺑﺘﺜﺒﻴﺘﻬﺎ ﰱ ﻣﺎﻛﻴﻨـﺔ ﺍﺧﺘﺒـﺎﺭ‬ ‫ﺍﻟﻀﻐﻂ ﲝﻴﺚ ﺗﻀﻤﻦ ﺗﻮﺍﺯﻯ ﻟﻮﺣﻰ ﻓﻜﻰ ﺍﻟﺘﺤﻤﻴﻞ ﺍﻟﻠﺬﻳﻦ ﺗﻮﺿﻊ ﺑﻴﻨﻬﻤﺎ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻭﲢﻤﻞ ﺍﻟﻌﻴﻨـﺔ‬ ‫ﲝﻴﺚ ﻳﻜﻮﻥ ﻣﻌﺪﻝ ﺍﻟﺘﺤﻤﻴﻞ ﺛﺎﺑﺘﺎ ﻋﻠﻰ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻭﻳﺘﻤﺎﺷﻰ ﻣﻊ ﻣﻌﺪﻝ ﺍﻟﺘﺸﻜﻴﻞ ﺍﻟﺬﻯ ﻗﻴﻤﺘﻪ ﺣﻮﺍﱃ‬ ‫‪ ٠,٠٦٣٥‬ﺳﻢ‪/‬ﺍﻟﺪﻗﻴﻘﺔ‪.‬‬ ‫* ﺍﻟﻨﺘﺎﺋﺞ ﻭﺍﳋﻮﺍﺹ ﺍﳌﻄﻠﻮﺑﺔ‪:‬‬ ‫ﻧﺮﺻﺪ ﻧﺘﺎﺋﺞ ﺍﻷﲪﺎﻝ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻭﻋﻨﺪ ﺍﻟﻜﺴﺮ ﻭﻛﺬﻟﻚ ﻧﺘﺎﺋﺞ ﺍﻟﺘﺸﻜﻞ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻭﻋﻨﺪ‬ ‫ﺍﻟﻜﺴﺮ ﻭﻟﻜﻦ ﳚﺐ ﺃﻥ ﻳﻜﻮﻥ ﺍﻟﻄﻮﻝ ﺍﳌﻘﺎﺱ ﻟﺘﻌﻴﲔ ﺍﻟﺘﺸﻜﻞ ﻣﻦ ﺍﺭﺗﻔﺎﻉ ﺍﻟﻌﻴﻨﺔ ﻻ ﻳﺰﻳﺪ ﻋﻦ ‪ %٧٥‬ﻣﻦ‬ ‫ﺍﺭﺗﻔﺎﻋﻬﺎ‪.‬‬ ‫ﻭﺗﻌﻴﲔ ﺍﳋﻮﺍﺹ ﺍﳌﻄﻠﻮﺑﺔ ﻣﻦ ﺍﻟﻌﻼﻗﺎﺕ ﺍﻵﺗﻴﺔ‪:‬‬ ‫ ﺇﺟﻬﺎﺩ ﺍﻟﻀﻐﻂ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ =‬‫‪ -‬ﺍﻻﻧﻔﻌﺎﻝ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ =‬

‫ﺍﳊﻤﻞ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ‬ ‫ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ‬

‫ﺍﻟﺘﺸﻜﻞ‬ ‫ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ‬

‫ﲪﻞ ﺍﻻ‪‬ﻴﺎﺭ‬ ‫ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻜﺴﺮ ﻋﻨﺪ ﺃﻗﺼﻰ ﲪﻞ =‬‫ﻣﺴﺎﺣﺔ ﺍﳌﻘﻄﻊ‬

‫‪ -‬ﻣﻌﺎﻳﺮ ﺍﳌﺮﻭﻧﺔ =‬

‫ﺇﺟﻬﺎﺩ ﺍﻟﻀﻐﻂ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ‬ ‫ﺍﻻﻧﻔﻌﺎﻝ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ‬

‫ﻛﺠﻢ‪/‬ﺳﻢ‬

‫‪٢‬‬

‫ﻣﻢ ‪/‬ﻣﻢ‬ ‫ﻛﺠﻢ‪/‬ﺳﻢ‬ ‫ﻛﺠﻢ‪/‬ﺳﻢ‬

‫‪٢‬‬

‫‪٢‬‬

‫ﺏ‪ .‬ﻣﻘﺎﻭﻣﺔ ﺍﻟﻀﻐﻂ ﰱ ﺍﲡﺎﻩ ﻋﻤﻮﺩﻯ ﻋﻠﻰ ﺗﺮﺗﻴﺐ ﺍﻷﻟﻴﺎﻑ‪.‬‬ ‫• ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ‪:‬‬ ‫ﺗﻜﻮﻥ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻠﻰ ﻣﻜﻌﺐ ﻃﻮﻟﻪ ‪٥‬ﺳﻢ ﻭﺑﻨﻔﺶ ﺍﻟﺸﺮﻭﻁ ﻭﺍﻷﺻـﻮﻝ ﺍﻟـﺴﺎﺑﻘﺔ ﰱ ﺍﻻﺧﺘﺒـﺎﺭ‬ ‫ﺍﻟﺴﺎﺑﻖ‪.‬‬

‫‪١٢٧‬‬


‫• ﻃﺮﻳﻘﺔ ﺍﻻﺧﺘﺒﺎﺭ‪:‬‬ ‫ﳚﺮﻯ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﺍﳌﻜﻌﺒﺔ ﺍﻟﺸﻜﻞ ﺑﻄﺮﻳﻘﺔ ﳑﺎﺛﻠﺔ ﻟﻄﺮﻳﻘﺔ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺗﻌﻴﲔ ﻣﻘﺎﻭﻣﺔ ﺍﻟﻀﻐﻂ ﰱ‬ ‫ﺍﲡﺎﻩ ﻣﻮﺍﺯﻯ ﻟﺘﺮﺗﻴﺐ ﺍﻷﻟﻴﺎﻑ‪.‬‬ ‫• ﺍﻟﻨﺘﺎﺋﺞ ﻭﺍﳋﻮﺍﺹ ﺍﳌﻄﻠﻮﺑﺔ‪:‬‬ ‫ﻧﺮﺻﺪ ﻧﺘﺎﺋﺞ ﺍﻷﲪﺎﻝ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ ﻭﻋﻨﺪ ﺍﻧﻀﻐﺎﻁ ﻗﻴﻤﺘﻪ ‪٠,٢٥‬ﺳﻢ ﻭﻋﻨﺪ ﺍﻻ‪‬ﻴﺎﺭ‪.‬‬ ‫ﻭﺗﻌﲔ ﺍﳋﻮﺍﺹ ﺍﳌﻄﻠﻮﺑﺔ ﻣﻦ ﺍﻟﻌﻼﻗﺎﺕ ﺍﻵﺗﻴﺔ‪:‬‬ ‫‪ -‬ﺇﺟﻬﺎﺩ ﺍﻟﻀﻐﻂ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ =‬

‫ﺡ‬ ‫ﻡ‬

‫ ﺇﺟﻬﺎﺩ ﺍﻟﻀﻐﻂ ﻋﻨﺪ ﺗﺸﻜﻞ ﻗﻴﻤﺘﻪ ‪٠,٢٥‬ﺳﻢ =‬‫‪ -‬ﺇﺟﻬﺎﺩ ﺍﻟﻀﻐﻂ ﻋﻨﺪ ﺍﻟﻜﺴﺮ =‬

‫ﺡ‪١‬‬

‫ﻡ‬

‫ﺡ‪٢‬‬

‫ﻡ‬

‫ﺣﻴﺚ ﺃﻥ ‪:‬‬ ‫ﻡ‪ :‬ﻣﺴﺎﺣﺔ ﻣﻘﻄﻊ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ‪.‬‬ ‫ﺡ‪ :‬ﲪﻞ ﺍﻟﻀﻐﻂ ﻋﻨﺪ ﺣﺪ ﺍﻟﺘﻨﺎﺳﺐ‪.‬‬ ‫ﺡ‪ :١‬ﲪﻞ ﺍﻟﻀﻐﻂ ﻋﻨﺪ ﺗﺸﻜﻞ ﻗﻴﻤﺘﻪ ‪٠,٢٥‬ﺳﻢ‪.‬‬ ‫ﺡ‪ :٢‬ﲪﻞ ﺍﻟﻀﻐﻂ ﻋﻨﺪ ﺍﻻ‪‬ﻴﺎﺭ‪.‬‬

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‫‪1+23( 45 3-7‬‬

‫‪@ @òß†Ôß@QMSMW‬‬ ‫ﻣﻦ ﺍﳌﻌﺮﻭﻑ ﺃﻥ ﲢﻤﻞ ﺍﳋﺮﺳﺎﻧﺔ ﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﻀﻐﻂ ﻋﺎﻟﻴﺔ ﻭﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﺸﺪ ﺿﻌﻴﻔﺔ ﺟﺪﹰﺍ ﻟﻜﻮ‪‬ﺎ ﻣﺎﺩﺓ‬ ‫ﻗﺼﻔﺔ ﻭﻏﲑ ﻣﺘﺠﺎﻧﺴﺔ ﲤﺎﻣﺎﹰ‪ ،‬ﻟﺬﻟﻚ ﺃﺳﺘﻠﺰﻡ ﻭﺿﻊ ﺍﻟﺼﻠﺐ ﺩﺍﺧﻞ ﺍﳋﺮﺳﺎﻧﺔ ﰱ ﺍﻷﻣﺎﻛﺎﻥ ﺍﻟﱴ ﻳﺘﻮﻟﺪ ﻓﻴﻬﺎ‬ ‫ﺇﺟﻬﺎﺩﺍﺕ ﺍﻟﺸﺪ ﻟﻴﺘﻮﱃ ﻋﻨﻬﺎ ﲢﻤﻞ ﻫﺬﻩ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺑﺎﻹﺿﺎﻓﺔ ﺃﻳﻀﺎ ﺇﱃ ﻭﺿﻌﻪ ﰱ ﻣﻨﺎﻃﻖ ﺍﻟﻀﻐﻂ ﻣﺜـﻞ‬ ‫ﺍﻷﻋﻤﺪﺓ ﺍﳋﺮﺳﺎﻧﻴﺔ ﻭﺫﻟﻚ ﺑﻐﺮﺽ ﺯﻳﺎﺩﺓ ﻗﺪﺭﺓ ﲢﻤﻞ ﻫﺬﻩ ﺍﻟﻌﻨﺎﺻﺮ ﻟﻸﲪﺎﻝ ﺍﳋﺎﺭﺟﻴﺔ ﻭﻟﺘﻘﻠﻴﻞ ﺍﻧﻜﻤـﺎﺵ‬ ‫ﺍﳋﺮﺳﺎﻧﺔ‪ .‬ﻭﻋﻤﻮﻣﺎ ﻳﺴﻤﻰ ﺍﻟﺼﻠﺐ ﺍﳌﺴﺘﺨﺪﻡ ﺩﺍﺧﻞ ﺍﳋﺮﺳﺎﻧﺔ ﲝﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﻭﺗﺴﻤﻰ ﺗﻠﻚ ﺍﳋﺮﺳـﺎﻧﺔ‬ ‫ﺑﺎﳋﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ‪.‬‬ ‫ﻭﻗﺪ ﺗﻄﻮﺭ ﺍﺳﺘﺨﺪﺍﻡ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﲟﺮﺍﺣﻞ ﻋﺪﻳﺪﺓ‪ ،‬ﻓﻘﺪ ﺑﺪﺃ ﺍﺳﺘﺨﺪﺍﻣﻪ ﰱ ﺍﻟﻌﺎﱂ ﻋﺎﻡ ‪١٨٥٤‬ﺣﻴـﺚ‬ ‫ﺣﺼﻞ ﺑﻼﺗﻼﻧﺪ ﻭﻳﻠﻜﻨﺶ ﻋﻠﻰ ﺑﺮﺍﺀﺓ ﺍﺧﺘﺮﺍﻉ ﳊﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ‪ ،‬ﻭﰱ ﻋﺎﻡ ‪ ١٩٨٦٥‬ﰎ ﺗﺸﻴﻴﺪ ﺃﻭﻝ ﻣﺒﲎ‬ ‫ﻣﻦ ﺍﳋﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ ﻭﺍﳌﺴﺘﺨﺪﻡ ﺣﺒﺎﻝ ﻣﱪﻭﻣﺔ ﻣﻦ ﺍﻟﺼﻠﺐ ﻣﻮﺿﻮﻋﺔ ﰱ ﻗﺎﻉ ﻛﻤﺮﺍﺕ ﺍﳌﺒﲎ‪ .‬ﻭﻣﻨـﺬ‬ ‫ﺍﺳﺘﺨﺪﺍﻡ ﺍﳋﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ ﰱ ﺃﻭﺍﺋﻞ ﺍﻟﻘﺮﻥ ﺍﻟﻌﺸﺮﻳﻦ ﻭﺿﻌﺖ ﻣﻮﺍﺻﻔﺎﺕ ﺍﻻﺟﻬﺎﺩﺍﺕ ﺍﳌـﺴﻤﻮﺡ ‪‬ـﺎ‬ ‫ﻷﺳﻴﺎﺥ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﻋﻠﻰ ﺃﺳﺎﺱ ﺃﻥ ﺇﺟﻬﺎﺩ ﺍﻟﺘﺸﻐﻴﻞ ﻻ ﻳﺘﻌﺪﻯ ﻟﻨﺼﻒ ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ‪ ،‬ﻭﻛـﺎﻥ ﰱ‬ ‫ﺗﻠﻚ ﺍﻵﻭﻧﺔ ﻛﺎﻥ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﺍﳌﺴﺘﺨﺪﻡ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﻟﻄﺮﻯ ﺍﻟﻌﺎﺩﻯ ﺍﳌﻌﺮﻭﻑ ﺑﺎﳊﺪﻳـﺪ ‪٢٤ / ٣٧‬‬ ‫)ﺃﻯ ﺃﻥ ﻣﻘﺎﻭﻣﺔ ﻟﻠﺸﺪ ‪٣٧‬ﻛﺠﻢ‪/‬ﺳﻢ‪ ٢‬ﻭﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﻟﻪ ‪٢٤‬ﻛﺠﻢ‪/‬ﺳﻢ‪ .٢‬ﰒ ﺑﺪﺃ ﺑﻌﺪ ﺫﻟﻚ ﻇﻬـﻮﺭ‬ ‫ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﻋﻠﻰ ﺍﳌﻘﺎﻭﻣﺔ ﰱ ﺃﻣﺮﻳﻜﺎ ﰒ ﻋﻤﻢ ﺇﻧﺘﺎﺟﻪ ﰱ ﺃﻭﺭﺑﺎ ﻓﺄﻧﺘﺠﺖ ﺍﳒﻠﺘﺮﺍ ﻭﻓﺮﻧﺴﺎ ﺍﳊﺪﻳـﺪ ‪٤٨‬‬ ‫ﻭﺃﳌﺎﻧﻴﺎ ﺍﳊﺪﻳﺪ ‪ ،٥٢‬ﻭﻛﺎﻥ ﺍﻟﻐﺮﺽ ﺍﻷﺳﺎﺳﻰ ﻣﻦ ﺍﻧﺘﺎﺝ ﺫﻩ ﺍﳊﺪﻳﺪ ﻭﺍﺳﺘﺨﺪﺍﻣﻪ ﰱ ﺍﳋﺮﺳﺎﻧﺔ ﻫﻮ ﺗـﻮﻓﲑ‬ ‫ﻛﻤﻴﺔ ﺍﳊﺪﻳﺪ ﺍﳌﺴﺘﺨﺪﻣﺔ ﻭﻣﺎ ﻳﺘﺒﻌﻪ ﻣﻦ ﺗﻘﻠﻴﻞ ﺃﺑﻌﺎﺩ ﻗﻄﺎﻋﺎﺕ ﺍﳋﺮﺳﺎﻧﺔ‪.‬‬ ‫ﻭﻟﻜﻦ ﻣﺼﺮ ﻗﺒﻞ ﺍﳊﺮﺏ ﺍﻟﻌﺎﳌﻴﺔ ﺍﻟﺜﺎﻧﻴﺔ ﻛﺎﻧﺖ ﺗﺴﺘﻮﺭﺩ ﲨﻴﻊ ﺍﺣﺘﻴﺎﺟﺎ‪‬ﺎ ﻣﻦ ﺫﻟﻚ ﺍﳊﺪﻳﺪ ﻣﻦ ﺩﻭﻝ ﺃﻭﺭﺑﺎ‬ ‫ﻭﺑﺎﻷﺧﺺ ﺍﳒﻠﺘﺮﺍ‪ ،‬ﻭﻗﺪ ﺑﺪﺃ ﺇﻧﺘﺎﺟﻪ ﳏﻠﻴﹰﺎ ﰱ ﻣﺼﺮ ﻣﻦ ﺍﳊﺪﻳﺪ ﺍﳋﺮﺩﺓ ﺍﳌﺘﻮﻓﺮ ﻣﻦ ﳐﻠﻔﺎﺕ ﺍﳊﺮﻭﺏ ﺑﻌـﺪ‬ ‫ﺍﳊﺮﺏ ﺍﻟﻌﺎﳌﻴﺔ ﺍﻟﺜﺎﻧﻴﺔ‪ .‬ﻭﳌﺎ ﻛﺎﻥ ﺍﳊﺪﻳﺪ ﺍﳋﺮﺩﺓ ﰱ ﺳﻴﺒﻠﻪ ﺇﱃ ﺍﻟﻨﻔﺎﺫ‪ ،‬ﻓﻘﺪ ﰎ ﺍﻟﺘﻮﺟـﻪ ﺇﱃ ﺍﺳـﺘﺨﻼﺹ‬ ‫ﺍﳊﺪﻳﺪ ﻣﻦ ﺧﺎﻣﺘﻪ ﺍﳌﺘﻮﻓﺮﺓ ﳏﻠﻴﹰﺎ ﰱ ﺍﻟﺒﻼﺩ ﺣﻴﺚ ﰎ ﺇﻧﺸﺎﺀ ﻣﺼﻨﻊ ﺍﳊﺪﻳﺪ ﻭﺍﻟﺼﻠﺐ ﲝﻠﻮﺍﻥ ﺑﻌـﺪ ﺛـﻮﺭﺓ‬ ‫ﻳﻮﻟﻴﻮ ﻋﺎﻡ ‪١٩٥٢‬ﻡ‪ ،‬ﰒ ﺑﺪﺃ ﺇﻧﺸﺎﺀ ﻣﺼﺎﻧﻊ ﺃﺧﺮﻯ ﻣﺜﻞ ﻣﺼﻨﻊ ﺷﺮﻛﺔ ﺍﻟﺪﻟﺘﺎ ﻭﻣﺼﻨﻊ ﺷـﺮﻛﺔ ﺍﻟﻨﺤـﺎﺱ‬ ‫ﺍﳌﺼﺮﻳﺔ ﻭﻣﺼﻨﻊ ﺍﻟﺪﺧﻴﻠﺔ ﻭﺣﺎﻟﻴﺎ ﻣﺼﻨﻊ ﺍﻟﻌﺰ‪.‬‬

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‫‪@ @(Types of Steel Bars Cross-Section)@|îÜnÛa@†í†y@pbÇbĐÓ@ÞbØ‘c@RMSMW‬‬ ‫ﻳﺘﻢ ﺍﻧﺘﺎﺝ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﺑﺎﻟﻘﻄﺎﻋﺎﺕ ﻭﺍﻷﺷﻜﺎﻝ ﺍﻟﺘﺎﻟﻴﺔ ﻭﺍﻟﱴ ﳝﻜﻦ ﺗﻘﺴﻴﻤﻬﺎ ﺇﱃ ‪:‬‬ ‫‪@ @(Plain Bars)@ÉĐÔ½a@ñŠí†nß@õbÜß@„bîc@Mc‬‬ ‫ﻭﻫﻰ ﺃﺳﻴﺎﺥ ﻣﺴﺘﺪﻳﺮﺓ ﺍﳌﻘﻄﻊ ﺗﻨﺘﺞ ﻋﻠﻰ ﺻﻮﺭﺓ ﻟﻔﺎﺋﻒ ﺑﺄﻗﻄﺎﺭ ﻣﻦ ‪٥‬ﻣﻢ ﺇﱃ ‪١٣‬ﻣﻢ‪ ،‬ﺃﻭ ﻋﻠـﻰ ﺻـﻮﺭﺓ‬ ‫ﺃﺳﻴﺎﺥ ﻃﻮﻟﻴﺔ ﻣﺴﺘﻘﻴﻤﺔ ﺑﺄﻃﻮﺍﻝ ﻻ ﺗﺘﻌﺪﻯ ‪١٢‬ﻡ ﻃﻮﱃ ﻭﺫﻟﻚ ﻟﻸﻗﻄﺎﺭ ﺍﻷﻛﱪ ﻣﻦ ‪١٣‬ﻣﻢ ﻭﺣﱴ ﺣﻮﺍﱃ‬ ‫‪٥٠‬ﻣﻢ‪ ،‬ﺃﻭ ﺗﻨﺘﺞ ﺑﺄﻃﻮﺍﻝ ﻭﺃﻗﻄﺎﺭ ﺧﺎﺻﺔ ﺣﺴﺐ ﺍﻟﻄﻠﺐ ﻣﻦ ﺍﳌﺼﻨﻊ ﺍﳌﻨﺘﺞ ﻭﻫﺬﻩ ﺍﻷﺳﻴﺎﺥ ﻫﻰ ﺍﻷﻛﺜـﺮ‬ ‫ﺷﻴﻮﻋﹰﺎ ﰱ ﺍﻻﺳﺘﺨﺪﺍﻡ ﻛﺤﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﰱ ﺇﻧﺘﺎﺝ ﺍﳋﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ ﳉﻤﻴﻊ ﺍﻟﻌﻨﺎﺻﺮ ﺍﻹﻧﺸﺎﺋﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ‪.‬‬ ‫‪@ @@ÉĐÔ½a@òÈiŠß@õbÜß@„bîc@Ml‬‬

‫ﻭﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻷﺳﻴﺎﺥ ﺍﳌﺮﺑﻌﺔ ﺍﳌﻘﻄﻊ ﳏﺪﻭﺩ ﺍﻻﺳﺘﺨﺪﺍﻡ ﰱ ﺃﻋﻤﺎﻝ ﺍﳋﺮﺳﺎﻧﺎﺕ ‪.‬‬ ‫‪@ @ôëbšîi@ëc@Ší†nß@ÉĐÔß@ë‡@kÜ–Ûa@åß@õbÜß@Úýc@M;u‬‬

‫ﻭﻫﻰ ﺃﺳﻼﻙ ﺑﻘﻄﺮ ﻣﻦ ‪ ١‬ﺇﱃ ‪١٠‬ﻣﻢ ﻭﺗﺴﺘﺨﺪﻡ ﰱ ﺃﻋﻤﺎﻝ ﺍﳋﺮﺳﺎﻧﺎﺕ ﺳﺎﺑﻘﺔ ﺍﻻﺟﻬﺎﺩ‪.‬‬ ‫‪(Deformed Bars) paûnã@pa‡@„bîc@Mõ‬‬

‫ﻭﻫﺬﻩ ﺍﻷﺳﻴﺎﺥ ﻣﺴﺘﺪﻳﺮﺓ ﺍﳌﻘﻄﻊ ﻭﻳﻮﺟﺪ ‪‬ﺎ ﻧﺘﺆﺍﺕ ﻋﺮﺿﻴﺔ ﺃﻭ ﻋﺮﺿﻴﺔ ﻭﻃﻮﻟﻴﺔ ﻣﻌﹰﺎ ﻭﻋﻠﻰ ﻛﺎﻣﻞ ﻃﻮﺏ‬ ‫ﺍﻷﺳﻴﺎﺥ ﻭﻫﺬﻩ ﺍﻟﻨﺘﺆﺍﺕ ﺫﺍﺕ ﺃﺑﻌﺎﺩ ﻭﺃﺷﻜﺎﻝ ﳐﺘﻠﻔﺔ ﺑﻐﺮﺽ ﺯﻳﺎﺩﺓ ﺍﻟﺘﻤﺎﺳﻚ ﻣﻊ ﺍﳋﺮﺳﺎﻧﺔ‪ .‬ﻭﻗـﺪ ﻳـﺘﻢ‬ ‫ﺇﻧﺘﺎﺝ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻷﺳﻴﺎﺥ ﺑﺄﻗﻄﺎﺭ ﺗﺘﺮﺍﻭﺡ ﻣﺎ ﺑﲔ ‪ ٥٠ ، ٨‬ﻣﻢ ﻭﺫﻟﻚ ﻋﻠﻰ ﺻﻮﺭﺓ ﺃﺳﻴﺎﺥ ﻣﺴﺘﻘﻴﻤﺔ‬ ‫ﺑﺄﻃﻮﺍﻝ ﻻ ﺗﺰﻳﺪ ﻋﻦ ‪١٢‬ﻡ ﺃﻭ ﺑﺎﻃﻮﺍﻝ ﺧﺎﺻﺔ ﻣﻄﻠﻮﺑﺔ ﻣﻦ ﺍﳌﺼﻨﻊ‪ ،‬ﻭﺗﺴﺘﺨﺪﻡ ﺃﻳﻀﺎ ﰱ ﺗـﺴﻠﻴﺢ ﻣﻌﻈـﻢ‬ ‫ﺍﻟﻌﻨﺎﺻﺮ ﻭﺍﳍﻴﺎﻛﻞ ﺍﻹﻧﺸﺎﺋﻴﺔ ﺍﳌﺨﺘﻠﻔﺔ ﰱ ﺍﻧﺘﺎﺝ ﺍﳋﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ‪.‬‬ ‫‪(Mesh) òØj‘@M;ç‬‬

‫ﻭﻫﺬﻩ ﺍﻟﺸﺒﻜﺔ ﻋﺒﺎﺭﺓ ﻋﻦ ﺃﺳﻴﺎﺥ ﺃﻭ ﺃﺳﻼﻙ ﻣﻦ ﺍﻟﺼﻠﺐ ﻣﻠﺤﻮﻣﺔ ﻣﻌﺎ‪ ،‬ﻭﺗﻜﻮﻥ ﺗﻠﻚ ﺍﻟﺸﺒﻜﺔ ﺇﻣﺎ ﻣﺮﺑﻌـﺔ‬ ‫ﺃﻭ ﻣﻌﻴﻨﺔ ﺍﻟﻔﺘﺤﺎﺕ ﻭﻳﺘﻢ ﺇﻧﺘﺎﺟﻬﺎ ﰱ ﺻﻮﺭﺓ ﺣﺼﲑﺓ ﺍﻭ ﻟﻔﺔ ﺣﻴﺚ ﺗﺴﺘﺨﺪﻡ ﻟﺘﺴﻠﻴﺢ ﺑﻼﻃﺎﺕ ﺍﻷﺳـﻘﻒ‬ ‫ﻭﺍﻟﻄﺮﻕ ﻭﺑﻼﻃﺎﺕ ﺍﻷﺭﺿﻴﺎﺕ‪.‬‬ ‫‪(Rolled Steel Section) òäÐÛ†½a@kÜ–Ûa@pbÇbĐÓ@Më‬‬

‫ﻭﻫﺬﻩ ﺍﻟﻘﻄﺎﻋﺎﺕ ﻣﻦ ﺍﻟﺼﻠﺐ ﺗﻜﻮﻥ ﻋﻠﻰ ﺃﺷﻜﺎﻝ ﳐﺘﻠﻔﺔ ﻣﺜﻞ ﺷﻜﻞ ‪ I‬ﺃﻭ ﺷﻜﻞ [ ﻭﻫﻰ ﺗﺴﺘﺨﺪﻡ ﻋﻠﻰ‬ ‫ﻫﻴﺌﺔ ﻛﻤﺮﺍﺕ ﺣﺪﻳﺪﻳﺔ ﺃﻭ ﺃﻋﻤﺪﺓ ﻃﺒﻘﺎ ﳌﺘﻄﻠﺒﺎﺕ ﺍﻟﺘﺼﻤﻴﻢ ﻭﺫﻟﻚ ﰱ ﺣﺎﻓﺔ ﺍﻷﲪﺎﻝ ﺍﻟﺜﻘﻴﻠﺔ ﻣﺜﻞ ﺍﻟﻜﺒﺎﺭﻯ‬ ‫ﻛﻤﺎ ﺗﺴﺘﺨﺪﻡ ﰱ ﺍﻟﻘﻄﺎﻋﺎﺕ ﺍﳌﺮﻛﺒﺔ )‪ (Composite Section‬ﺃﻭ ﻛﻘﻀﺒﺎﻥ ﻟﻠﺴﻚ ﺍﳊﺪﻳﺪﻳﺔ‪.‬‬ ‫‪١٣٠‬‬


‫‪@ @@(Types of Steel Bars)@|îÜnÛa@†í†y@Êaìãc@SMSMW‬‬ ‫ﺣﻴﺚ ﺃﻧﻪ ﳝﻜﻦ ﺗﻘﺴﻴﻢ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﻣﻦ ﺣﻴﺚ ﺍﳌﻘﺎﻭﻣﺔ ﺇﱃ ﺍﻷﻧﻮﺍﻉ ﺍﻟﺮﺋﻴﺴﻴﺔ ﺍﻟﺘﺎﻟﻴﺔ ‪:‬‬ ‫‪Ordinary Mild Steel ô…bÈÛa@ôŠĐÛa@kÜ–Ûa@Mc‬‬

‫ﻭﻫﻮ ﻳﺼﻨﻊ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﻟﻜﺮﺑﻮﱐ ﺣﻴﺚ ﳚﺐ ﺃﻻ ﺗﺰﻳﺪ ﻧﺴﺒﺔ ﺍﻟﻜﺮﺑﻮﻥ ﻓﻴـﻪ ﻋـﻦ ‪ ،%٠,٢‬ﻭﻧـﺴﺒﺔ‬ ‫ﺍﻟﻔﻮﺳﻔﻮﺭ ﻭﺍﻟﻜﱪﻳﺖ ﻣﻌﺎ ﻋﻦ ‪ ،%٠,١٣‬ﻭﻻ ﺗﻘﻞ ﻣﻘﺎﻭﻣﺘﻪ ﻟﻠﺸﺪ ﻋﻦ ‪ ٣٥‬ﻛﺠﻢ‪/‬ﻣـﻢ‪ ، ٢‬ﻭﻳـﺘﻢ‬ ‫ﺍﻧﺘﺎﺟﻪ ﲜﻤﻴﻊ ﺃﺷﻜﺎﻝ ﺍﻟﻘﻄﺎﻋﺎﺕ ﺍﻟﺴﺎﺑﻖ ﺫﻛﺮﻫﺎ‪ .‬ﻭﻋﺎﺩﺓ ﻳﺴﺘﺨﺪﻡ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟـﺼﻠﺐ ﺍﻟﻄـﺮﻯ‬ ‫ﺍﻟﻌﺎﺩﻯ ﻛﺤﺪﻳﺪ ﺗﺴﻠﻴﺢ ﻟﻠﺨﺮﺳﺎﻧﺎﺕ ﺍﻟﱵ ﺗﺰﻳﺪ ﻣﻘﺎﻭﻣﺘـﻬﺎ ﻟﻠـﻀﻐﻂ ﺑﻌـﺪ ‪ ٢٨‬ﻳـﻮﻡ ﻋـﻦ ‪١٧٥‬‬ ‫ﻛﺠﻢ‪/‬ﺳﻢ‪.٢‬‬ ‫‪(High Tensile Steel) òßëbÔ½a@µbÈÛa@kÜ–Ûa@Ml‬‬

‫ﻭﻳﻨﺘﺞ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻋﻠﻰ ﻫﻴﺌﺔ ﺃﺳﻴﺎﺥ ﻣﺼﻨﻌﺔ ﻣﻠﺴﺎﺀ ﺃﻭ ﺫﺍﺕ ﻧﺘﺆﺍﺕ ﻭﺇﻥ ﻛﺎﻧﺖ ﺍﻷﺳﻴﺎﺥ ﺫﺍﺕ ﺍﻟﻨﺘﺆﺍﺕ‬ ‫ﻫﻰ ﺍﻟﻐﺎﻟﺒﺔ ﰱ ﺍﻻﻧﺘﺎﺝ ﰱ ﺍﻷﺳﻮﺍﻕ ﺍﳌﺼﺮﻳﺔ ﻭﺫﻟﻚ ﻟﻐﺮﺽ ﲢﺴﲔ ﺧﺎﺻﻴﺔ ﺍﻟﺘﻤﺎﺳﻚ ﺑﻴﻨﻬﺎ ﻭﺑﲔ ﺍﳋﺮﺳﺎﻧﺔ‬ ‫ﺍﳌﺪﻓﻮﻥ ﳍﺎ‪ .‬ﻭﻫﻮ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﻟﻜﺮﺑﻮﱏ ﺣﻴﺚ ﳚﺐ ﺃﻻ ﺗﺰﻳﺪ ﻧﺴﺒﺔ ﺍﻟﻜﺮﺑﻮﻥ ﻓﻴﻪ ﻋﻦ ‪ %٠,٣‬ﻭﻧـﺴﺒﺔ‬ ‫ﺍﻟﻔﻮﺳﻔﻮﺭ ﻋﻦ ‪ %٠,٠٥‬ﻭﻧﺴﺒﺔ ﺍﻟﻜﱪﻳﺖ ﻋﻦ ‪ %٠,٠٥‬ﻭﻳﺘﻢ ﺇﻧﺘﺎﺝ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﻟﻌـﺎﱃ‬ ‫ﺍﳌﻘﺎﻭﻣﺔ ﰱ ﺍﻟﺼﻮﺭ ﺍﻵﺗﻴﺔ‪:‬‬ ‫• ﺻﻠﺐ ﻋﺎﱃ ﺍﳌﻘﺎﻭﻣﺔ ﺭﺗﺒﺔ )‪ : (٥٢‬ﻭﻫﻮ ﺻﻠﺐ ﻛﺮﺑﻮﱏ ﻻ ﺗﺰﻳﺪ ﻧﺴﺒﺔ ﺍﻟﻜﺮﺑـﻮﻥ ﻓﻴـﻪ ‪، %٠,٣‬‬ ‫ﻭﻣﻘﺎﻭﻣﺘﻪ ﻟﻠﺸﺪ ﻻ ﺗﻘﻞ ﻋﻦ ‪ ٥٢‬ﻛﺠﻢ‪/‬ﻣﻢ‪.٢‬‬ ‫• ﺻﻠﺐ ﻣﻌﺎﰿ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ )‪ : (Cold Worked Steel‬ﻭﻫﻮ ﺻﻠﺐ ﻛﺮﺑﻮﱏ ﻋﺒﺎﺭﺓ ﻋـﻦ ﺻـﻠﺐ‬ ‫ﻃﺮﻯ ﺗﻌﺮﺽ ﻟﻌﻤﻠﻴﺎﺕ ﺍﻟﺘﺸﻐﻴﻞ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﺃﻭ ﺍﻟﻠﻰ ﺃﻭ ﻛﻠﻴﻬﻤﺎ ﻛﻰ ﻳﻜﺘﺴﺐ ﻫﺬﺍ ﺍﳊﺪﻳﺪ ﺑﺘﻠـﻚ‬ ‫ﺍﻟﻌﻤﻠﻴﺎﺕ ﻣﻘﺎﻭﻣﺔ ﻋﺎﻟﻴﺔ ﰱ ﺍﻟﺸﺪ ﻻ ﺗﻘﻞ ﻋﻦ ‪٥٠‬ﻛﺠﻢ‪/‬ﻣﻢ‪.٢‬‬ ‫ﻭﳚﺐ ﺍﻷﺧﺬ ﰱ ﺍﻻﻋﺘﺒﺎﺭ ﺃﻥ ﻳﺴﺘﺨﺪﻡ ﺍﻟﺼﻠﺐ ﺍﻟﻌﺎﱃ ﺍﳌﻘﺎﻭﻣﺔ ﰱ ﺗﺴﻠﻴﺢ ﺍﳋﺮﺳـﺎﻧﺎﺕ ﺫﺍﺕ ﻣﻘﺎﻭﻣـﺔ‬ ‫ﻟﻠﻀﻐﻂ ﻻ ﺗﻘﻞ ﻋﻦ ‪٢٠٠‬ﻛﺠﻢ‪/‬ﺳﻢ‪ ٢‬ﺑﻌﺪ ‪ ٢٨‬ﻳﻮﻡ‪ ،‬ﺣﱴ ﺗﺘﻤﺎﺷﻰ ﻭﺗﺘﻨﺎﺳﺐ ﺍﻻﺟﻬـﺎﺩﺍﺕ ﺍﳌﺮﺗﻔﻌـﺔ‬ ‫ﻟﻠﺼﻠﺐ ﻣﻊ ﺍﺟﻬﺎﺩﺍﺕ ﺍﻟﻀﻐﻂ ﻟﻠﺨﺮﺳﺎﻧﺔ ﻭﺯﻳﺎﺩﺓ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺘﻤﺎﺳﻚ‪ .‬ﻭﺃﻳﻀﺎ ﳚﺐ ﻣﻌﺮﻓﺔ ﺃﻥ ﺍﻷﺳـﻼﻙ‬ ‫ﺫﺍﺕ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻌﺎﻟﻴﺔ ﺍﻟﺼﻠﺒﺔ ﺗﺴﺘﺨﺪﻡ ﻓىﺎﳋﺮﺳﺎﻧﺔ ﺳﺎﺑﻘﺔ ﺍﻻﺟﻬﺎﺩ ﻭﻫﻰ ﺃﺳﻼﻙ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﳌﺴﺤﻮﺏ‬ ‫ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ‪.‬‬ ‫‪١٣١‬‬


‫‪@ @@(Manufacturing of Steel Bars)@|îÜnÛa@†í†y@òÇbä•@TMSMW‬‬ ‫ﲣﺘﻠﻒ ﻃﺮﻕ ﺗﺼﻨﻴﻊ ﺍﳊﺪﻳﺪ ﻃﺒﻘﺎ ﻟﻨﻮﻉ ﻭﺍﻟﺸﻜﻞ ﺍﳌﻄﻠﻮﺏ‪.‬‬ ‫‪@ @@ôŠĐÛa@kÜ–Ûa@@Ma‬‬

‫ﺇﻥ ﺻﻨﺎﻋﺔ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﻟﻄﺮﻯ ﺍﻟﻌﺎﺩﻯ ﲤﺮ ﺑﻌﺪﻩ ﻣﺮﺍﺣﻞ ﻫﻰ ﻛﺎﻵﰐ ‪:‬‬ ‫‪ -١‬ﻳﺘﻢ ﺍﺳﺘﺨﻼﺹ ﺍﳊﺪﻳﺪ ﺍﳋﺎﻡ ﻣﻦ ﺍﻟﺮﻛﺎﺯ ﺑﺎﻟﻔﺮﻥ ﺍﻟﻌﺎﱃ‪.‬‬ ‫‪ -٢‬ﻳﺘﻢ ﺍﻧﺘﺎﺝ ﺍﻟﺼﻠﺐ ﺍﻟﻄﺮﻯ ﻣﻦ ﺍﳊﺪﻳﺪ ﺍﳋﺎﻡ ﺑﻮﺍﺳﻄﺔ ﳏﻮﻻﺕ ﺑﺴﻤﺮ ﺃﻭ ﺑـﺄﻓﺮﺍﻥ ﺳـﻴﻤﱰ‬ ‫)ﺍﻷﻓﺮﺍﻥ ﺍﳌﻔﺘﻮﺣﺔ( ﺃﻭ ﺍﻷﻓﺮﺍﻥ ﺍﻟﻜﻬﺮﺑﺎﺋﻴﺔ‪.‬‬ ‫‪ -٣‬ﻳﺘﻢ ﺩﻟﻔﻨﺔ ﺍﳊﺪﻳﺪ ﺍﻟﺼﻠﺐ ﻋﻠﻰ ﺍﻟﺴﺎﺧﻦ ﻋﻠﻰ ﻫﻴﺌﺔ ﺃﺳﻴﺎﺥ ﺑﻘﻄﺎﻋـﺎﺕ ﻭﺃﻗﻄـﺎﺭ ﳐﺘﻠﻔـﺔ‬ ‫ﺗﺸﻜﻞ ﻋﻠﻰ ﻫﻴﺌﺔ ﻟﻔﺎﺋﻒ ﺃﻭ ﺃﺳﻴﺎﺥ ﻣﺴﺘﻘﻴﻤﺔ ﺗﻘﻄﻊ ﺣﱴ ﺃﻃﻮﺍﻝ ‪١٢‬ﻡ‪.‬‬ ‫ﺗﺴﺘﺨﺪﻡ ﺑﻌﺾ ﻣﻦ ﻣﺼﺎﻧﻊ ﺍﻧﺘﺎﺝ ﺃﺳﻴﺎﺥ ﺍﻟﺼﻠﺐ ﺍﻟﻄﺮﻯ ﻃﺮﻳﻘﺔ ﺗﻮﻣﺎﺱ ﻣﺜﻞ ﺷﺮﻛﺔ ﺍﳊﺪﻳﺪ ﻭﺍﻟـﺼﻠﺐ‬ ‫ﲝﻠﻮﻥ ‪ ،‬ﺣﻴﺚ ﺍ‪‬ﺎ ﺗﻘﻮﻡ ﺗﻨﻘﻴﺘﻪ ﺍﳊﺪﻳﺪ ﺍﳋﺎﻡ ﺑﻨﻔﺦ ﺍﳍﻮﺍﺀ ﺍﻟﺴﺎﺧﻦ ﺧﻼﻟﻪ ﻭﻳﺴﺘﻤﺮ ﺫﻟـﻚ ﺣـﻮﺍﱃ ‪١٦‬‬ ‫ﺩﻗﻴﻘﺔ ﻟﺘﺤﺘﺮﻕ ﺍﻟﺸﻮﺍﺋﺐ ﻭﻣﺎ ﳛﻴﻮﻩ ﺍﳋﺎﻡ ﻣﻦ ﺍﻟﻜﺮﺑﻮﻥ ﺍﻟﺬﻯ ﳚﺮﻯ ﺗﻌﻮﻳﻀﻪ ﺑﺎﻟﻨﺴﺒﺔ ﺍﳌﻄﻠﻮﺑﺔ ﺑﺈﺿـﺎﻓﺔ‬ ‫ﻣﻮﺍﺩ ﺣﺎﻭﻳﺔ ﻟﻪ ﺑﻌﺪ ﺍﻧﺘﻬﺎﺀ ﺍﻟﻌﻤﻠﻴﺔ ﰒ ﳚﺮﻯ ﺻﺐ ﺍﳊﺪﻳﺪ ﺍﳌﻨﺼﻬﺮ ﰱ ﺍﻟﻘﻮﺍﻟـﺐ ﻟﻠﺘﺠﻤـﺪ ﰒ ﻳـﺼﲑ‬ ‫ﺗﺴﺨﻴﻨﻬﺎ ﻭﺩﻟﻔﻨﺘﻬﺎ ﺑﻘﻄﺎﻋﺎﺕ ﺍﻷﺳﻴﺎﺥ ﺍﳌﻄﻠﻮﺑﺔ‪ .‬ﻭﻳﺴﺘﺨﺪﻡ ﺑﻌﺾ ﺷﺮﻛﺎﺕ ﺍﻻﻧﺘﺎﺝ ﳊﺪﻳـﺪ ﺍﻟﺘـﺴﻠﻴﺢ‬ ‫ﻃﺮﻗﹰﺎ ﺃﺧﺮﻯ ﻛﺎﻷﻓﺮﺍﻥ ﺍﳌﻔﺘﻮﺣﺔ ﻣﺜﻞ ﺷﺮﻛﺔ ﺍﻟﻨﺤﺎﺱ ﺍﳌﺼﺮﻳﺔ ﻭﻃﺮﻳﻘﺔ ﺍﻷﻓﺮﺍﻥ ﺍﻟﻜﻬﺮﺑﺎﺋﻴﺔ ﻣﺜﻞ ﺷـﺮﻛﺔ‬ ‫ﻣﺼﺎﻧﻊ ﺍﻟﺪﻟﺘﺎ ﻟﻠﺤﺪﻳﺪ ﺍﻟﺼﻠﺐ‪.‬‬ ‫‪@ @@@òßëbÔ½a@µbÇ@k–Ûa@@Ml‬‬

‫ﻏﺎﻟﺒﺎﹰ ﻳﺘﻢ ﺗﺼﻨﻴﻊ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺼﻠﺐ ﺑﻄﺮﻳﻘﺔ ﲰﻴﱰ "ﺍﻷﻓﺮﺍﻥ ﺍﳌﻔﺘﻮﺣـﺔ" ﺃﻭﺍﻷﻓـﺮﺍﻥ ﺍﻟﻜﻬﺮﺑﺎﺋﻴـﺔ‪،‬‬ ‫ﻭﻳﺴﺘﻠﺰﻡ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺼﻠﺐ ﺇﱃ ﻋﻤﻞ ﺗﻌﺪﻳﻞ ﻟﻪ ﻭﺫﻟﻚ ﺑﺈﺿﺎﻓﺔ ﺑﻌﺾ ﺍﶈـﺴﻨﺎﺕ ﺍﳌﻌﺮﻭﻓـﺔ ﻣﺜـﻞ‬ ‫ﺍﻟﻜﺮﻭﻡ ﻭﺍﳌﻨﺠﻨﻴﺰ ﻭﺍﻟﺴﻠﻴﻜﺎ ﻭﺫﻟﻚ ﺑﻨﺴﺐ ﻣﻌﻴﻨﺔ ﺑﻐﺮﺽ ﺭﻓﻊ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﺍﳌﺼﻨﻊ ﻭﺫﻟﻚ ﻣﻊ ﻣﺮﺍﻋﺎﺓ‬ ‫ﺇﻧﺘﺎﺝ ﺃﺳﻴﺎﺥ ﻫﺬﺍ ﺍﻟﺼﻠﺐ ﻋﻨﺪ ﺩﻟﻔﻨﺘﻬﺎ ﻟﺘﻜﻮﻥ ﺫﺍﺕ ﻧﺘﺆﺍﺕ ﻭﻳﺘﻢ ﻣﻌﺮﻓﺔ ﺭﺗﺒﺔ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﺑـﺮﻗﻤﻦ‬ ‫ﻣﺜﻼ )‪ (٥٢/٣٦‬ﺍﻟﺮﻗﻢ ﺍﻻﻭﻝ ﻳﻌﱪ ﻋﻦ ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ ﻭﺍﻟﺜﺎﱏ ﻋﻠﻰ ﺇﺟﻬﺎﺩ ﺍﻟﺸﺪ ) ﺑﺎﻟﻜﺠﻢ‪/‬ﻣﻢ‪.(٢‬‬ ‫‪…‰bjÛa@óÜÇ@bÈ½a@kÜ–Ûa@M;u‬‬

‫ﻳﺘﻢ ﲡﻬﻴﺰ ﻫﺬﺍ ﺍﻟﺼﻠﺐ ﺑﺈﺟﻬﺎﺩ ﺍﻟﺼﻠﺐ ﺍﻟﻌﺎﺩﻯ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﺇﱃ ﻣﺎ ﺑﻌﺪ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﻟﺘﺤﺴﲔ ﺍﳌﻘﺎﻭﻣـﺔ‬ ‫ﺍﳌﺮﻧﺔ ﻭﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻜﻠﻴﺔ ﻟﻠﺼﺐ‪ ،‬ﻭﺗﻌﻤﻞ ﺍﳌﻌﺎﳉﺔ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﺇﻣﺎ ﺑﺎﻟﺸﺪ ﺍﻟﻄﻮﱃ ﻭﺫﻟﻚ ﺇﺫﺍ ﺃﻣﻜﻦ ﺿـﻤﺎﻥ‬ ‫ﺍﻧﺘﻈﺎﻡ ﺗﻮﺯﻳﻊ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻋﻠﻰ ﻃﻮﻝ ﺃﺟﺰﺍﺀ ﺍﻟﺴﻴﺦ ﺃﻭ ﺍﻟﻠﻰ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻟﻸﺳﻴﺎﺥ ﻭﻫـﻰ ﺃﻓـﻀﻞ ﻣـﻦ‬ ‫‪١٣٢‬‬


‫ﺍﻟﻄﺮﻳﻘﺔ ﺑﺎﻟﺸﺪ ﺍﻟﻄﻮﱃ ﺣﻴﺚ ﺃﻥ ﻋﻤﻠﻴﺔ ﺍﻟﻠﻰ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻭﻟﻜﻦ ﳏﺪﺩﺓ ﺍﳋﻄﻮﺓ ﲟﺎ ﻻ ﻳﻘﻞ ﻋﻦ ‪ ٨‬ﻣﺮﺍﺕ‬ ‫ﻗﻄﺮ ﺍﻟﺴﻴﺦ ﻭﺗﻌﺘﱪ ﺍﺧﺘﺒﺎﺭ ﻟﻸﺳﻴﺎﺥ ﻧﻔﺴﻬﺎ ﻭﺗﻨﻈﻴﻢ ﻟﺮﻓﻊ ﺍﳌﻘﺎﻭﻣﺔ ﻋﻠﻰ ﻃﻮﻝ ﺍﻟﺴﻴﺦ‪.‬‬ ‫‪…bèu⁄a@òÔib@òãbŠ‚ÜÛ@òîÛbÈÛa@òßëbÔ½a@pa‡@Úýþa@Mõ‬‬

‫ﻭﻳﺘﻢ ﺇﻧﺘﺎﺝ ﻫﺬﻩ ﺍﻷﺳﻼﻙ ﺑﺮﻓﻊ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺼﻠﺐ ﺑﻜﻞ ﺍﻟﻄﺮﻕ ﻣﻦ ﺇﺿﺎﻓﺔ ﳏﺴﻨﺎﺕ ﺃﻭ ﻣﻌﺎﳉﺔ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ‬ ‫‪ ،‬ﻭﺗﻨﺘﺞ ﻫﺬﻩ ﺍﻻﺳﻼﻙ ﺑﻘﻄﺎﻋﺎﺕ ﻣﺴﺘﺪﻳﺮﺓ ﺍﻭ ﺑﻴﻀﺎﻭﻳﺔ ﻭﺗﻌﺮﻑ ﺩﺍﺋﻤﺎ ﺑﺮﻗﻤﲔ ﺍﻷﻭﻝ ﻳﺪﻝ ﻋﻠـﻰ ﺣـﺪ‬ ‫ﺍﳌﺮﻭﻧﺔ ﻭﺍﻟﺜﺎﱏ ﻋﻠﻰ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ )ﺑﺎﻟﻜﺠﻢ‪/‬ﻣﻢ‪.(٢‬‬ ‫ﻼ ﺻﻠﺐ )‪ (١٦٠-١٣٠‬ﺗﻌﲎ ﺣﺪ ﺍﳌﺮﻭﻧﺔ ﺗﺴﺎﻭﻯ ‪ ١٣٠‬ﻛﺠﻢ‪/‬ﻣﻢ‪ ٢‬ﻭﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻟﻠـﺸﺪ‬ ‫ﻓﻤﺜ ﹰ‬ ‫ﺗﺴﺎﻭﻯ ‪ ١٦٠‬ﻛﺠﻢ‪/‬ﻣﻢ‪.٢‬‬ ‫‪@ @@|îÜnÛa@†í†y@âb§@UMSMW‬‬ ‫ﳚﻮﺯ ﻭﺻﻞ ﺍﺳﻴﺎﺥ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﺇﺫﺍ ﻛﺎﻥ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﻟﻌﺎﺩﻯ ﺃﻭ ﻋﺎﱃ ﺍﳌﻘﺎﻭﻣﺔ ﻭﺫﻟﻚ ﺑﺎﻟﻠﺤﺎﻡ ﺣﻴﺚ‬ ‫ﺃﻧﻪ ﻫﻨﺎﻙ ﻋﺪﺓ ﻃﺮﻕ ﻣﺴﺘﻌﻤﻠﺔ ﻟﻠﺤﺎﻡ ﺃﳘﻬﺎ ‪:‬‬ ‫@‪@ @‹bÌÛbi@âbzÜÛa@J‬‬ ‫@@‬ ‫@@‬ ‫@‪@@ @@óiŠèØÛa@âbzÜÛa@J‬‬ ‫@‬ ‫ﻣﻊ ﺍﻷﺧﺬ ﰱ ﺍﻻﻋﺘﺒﺎﺭ ﺃﻥ ﻋﻤﻠﻴﺔ ﺍﻟﻠﺤﺎﻡ ﻳﻨﺒﻐﻰ ﺃﻻ ﺗﺆﺛﺮ ﻋﻠﻰ ﻣﻌﺪﻥ ﺍﻟﺴﻴﺦ ﺃﻭ ﺃ‪‬ﺎ ﻻ ﺗﻐﲑ ﻣﻦ ﺍﺳـﺘﻘﺎﻣﺔ‬ ‫ﳏﻮﺭ ﺍﻟﺴﻴﺦ ﺃﻭ ﻣﻦ ﺍﻟﻮﺿﻊ ﺍﳌﻄﻠﻮﺏ ﻟﻠﻘﻀﺒﺎﻥ ﻋﻨﺪ ﺍﻟﻮﺻﻠﺔ‪ ،‬ﺃﻣﺎ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﺼﻠﺐ ﻋﺎﱃ ﺍﳌﻘﺎﻭﻣﺔ ﻭﺍﳌﻌﺎﰿ‬ ‫ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻓﻼ ﻳﺴﻤﺢ ﻏﺎﻟﺒﺎ ﺑﻠﺤﺎﻣﻪ ﺇﻻ ﰱ ﺍﳊﺎﻻﺕ ﺍﳋﺎﺻﺔ ﲝﻴﺚ ﺗﺴﺘﺨﺪﻡ ﺣﺮﺍﺭﺓ ﳊﺎﻡ ﻏﲑ ﻣﺮﺗﻔﻌـﺔ‬ ‫ﻣﻊ ﺿﺮﻭﺭﺓ ﻣﻌﺎﳉﺔ ﺍﳌﻮﺍﺿﻊ ﺍﳌﻠﺤﻮﻣﺔ ﺑﻌﺪ ﺇﺟﺮﺍﺀ ﻋﻤﻠﻴﺔ ﺍﻟﻠﺤﺎﻡ‪.‬‬ ‫ﻭﺗﺒﲔ ﺍﻷﺷﻜﺎﻝ ﺍﻵﺗﻴﺔ ﻛﻴﻔﻴﺔ ﻭﺻﻞ "ﺃﺳﻴﺎﺥ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﺍﳌﺨﺘﻠﻔﺔ"‪.‬‬

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‫‪@ @@|îÜnÛa@†í†y@åíŒ¥@VMSMW‬‬ ‫ﳚﺐ ﺃﻥ ﺗﺘﻮﺍﻓﺮ ﺍﻟﺸﺮﻭﻁ ﺍﻟﺘﺎﻟﻴﺔ ﰱ ﲣﺰﻳﻦ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ‪:‬‬ ‫* ﻳﺘﻢ ﲣﺰﻳﻦ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﺃﻓﻘﻴﺎ‪.‬‬ ‫* ﻳﺘﻢ ﲣﺰﻳﻦ ﻛﻞ ﻗﻄﺮ ﻣﻦ ﺃﻗﻄﺎﺭ ﺍﳊﺪﻳﺪ ﻋﻠﻰ ﺣﺪﻩ‪.‬‬ ‫* ﻳﺘﻢ ﲣﺰﻳﻦ ﺍﳊﺪﻳﺪ ﰱ ﺭﺻﺎﺕ ﻋﻠﻰ ﻋﻮﺍﺭﺽ ﺧﺸﺒﻴﺔ ﻟﺮﻓﻌﻬﺎ ﻋﻦ ﺍﻷﺭﺽ ﺍﻟﻄﺒﻴﻌﻴﺔ‬

‫ﻟـﻀﻤﺎﻥ‬

‫ﻋﺪﻡ ﺗﺄﺛﲑ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﺑﺎﻟﺮﻃﻮﺑﺔ ﺃﻭ ﺃﻯ ﻣﻴﺎﻩ ﺃﻣﻄﺎﺭ ﺃﻭ ﳎﺎﺭﻯ‪.‬‬ ‫* ﻣﻦ ﺍﻟﻀﺮﻭﺭﻯ ﺗﻐﻄﻴﺔ ﺍﳊﺪﻳﺪ ﺍﳌﺨﺰﻥ ﰱ ﺍﳌﻨﺎﻃﻖ ﺷﺪﻳﺪﺓ ﺍﻟﺮﻃﻮﺑﺔ‪.‬‬ ‫* ﻳﺘﻢ ﺭﺹ ﺍﳊﺪﻳﺪ ﺑﺄﺳﻠﻮﺏ ﻳﺴﻬﻞ ﻋﻠﻰ ﺍﳌﻨﻔﺬ ﺭﻓﻊ ﺍﻟﻜﻤﻴﺎﺕ ﻭﺍﻷﻗﻄﺎﺭ ﺍﳌﻄﻠﻮﺑﺔ ﻃﺒﻘﹰﺎ ﻷﻭﻟﻮﻳـﺔ‬ ‫ﺍﻟﺘﻨﻔﻴﺬ‪.‬‬ ‫* ﳚﺐ ﺃﻥ ﺗﻜﻮﻥ ﺃﻣﺎﻛﻦ ﺍﻟﺘﺨﺰﻳﻦ ﺑﻌﻴﺪﺓ ﻋﻦ ﺃﻯ ﺷﺤﻮﻡ ﺃﻭ ﺯﻳﻮﺕ‪.‬‬ ‫* ﳚﺐ ﺗﻮﺍﻓﺮ ﺃﻣﺎﻛﻦ ﺧﺎﻟﻴﺔ ﻭﳑﺮﺍﺕ ﺑﲔ ﺭﺻﺎﺕ ﺍﳊﺪﻳﺪ ﻟﺘﺴﻬﻴﻞ ﻋﻤﻠﻴﺎﺕ ﺭﻓﻊ ﻭﺗﱰﻳﻞ ﺍﳊﺪﻳﺪ‪.‬‬

‫‪@ @NòzÜ½a@òãbŠä@ÞbàÇc@óÏ@|îÜnÛa@„bîc@kÜ•@âa†‚na@òîyý•@pba‘a@WMSMW‬‬ ‫ﻗﺪ ﻧﺼﺖ ﺍﳌﻮﺻﻔﺎﺕ ﺍﻟﻘﻴﺎﺳﻴﺔ ﻷﺳﻴﺎﺥ ﺍﻟﺼﻠﺐ ﻟﺘﺴﻠﻴﺢ ﺍﳋﺮﺳﺎﻧﺔ ﻋﻠﻰ ﺍﻻﻫﺘﻤﺎﻡ ﲜﻮﺩﺓ ﺗﺼﻨﻴﻊ ﺍﻷﺳﻴﺎﺥ‬ ‫ﻋﻠﻰ ﺃﻥ ﺗﻜﻮﻥ ﲨﻴﻊ ﺍﻷﺳﻴﺎﺥ ﺳﻠﻴﻤﺔ ﻭﺧﺎﻟﻴﺔ ﻣﻦ ﺍﻟﺘﺸﻘﻘﺎﺕ ﻭﺍﻟﻌﻴﻮﺏ ﺍﻟﺴﻄﺤﻴﺔ ﻭﺍﻟﻘﺸﻮﺭ ﻭﻏﲑ ﺫﻟـﻚ‬ ‫ﻣﻦ ﺍﻟﻌﻴﻮﺏ ﺍﻟﻀﺎﺭﺓ ﰱ ﺍﻻﺳﺘﻌﻤﺎﻝ‪ ،‬ﻭﺫﻟﻚ ﻷﺳﻴﺎﺥ ﺍﻟﺼﻠﺐ ﺍﻟﻜﺮﺑﻮﱏ ﺍﳌﺼﻨﻮﻋﺔ ﺑﻄﺮﻳﻘـﺔ ﺑـﺴﻤﺮ ﺃﻭ‬ ‫ﺑﺎﻟﻄﺮﻳﻘﺔ ﺍﻟﻜﻬﺮﺑﺎﺋﻴﺔ ﺃﻭ ﺑﻄﺮﻳﻘﺔ ﺍﻟﻔﺮﻥ ﺍﳌﻔﺘﻮﺡ )ﲰﱰ ﻣﺎﺭﺗﻦ( ﺃﻭ ﺑﺄﻯ ﻃﺮﻳﻘﺔ ﺃﺧﺮﻯ ﻳﺘﻔﻖ ﻋﻠﻴﻬـﺎ ﻋﻨـﺪ‬ ‫ﺍﻟﺘﻌﺎﻗﺪ ﻟﻠﺘﺼﻨﻴﻊ‪ .‬ﻭﻳﻜﻮﻥ ﺍﻟﺼﻠﺐ ﺍﻟﺬﻯ ﺗﺼﻨﻊ ﻣﻨﻪ ﺍﻷﺳﻴﺎﺥ ﺇﻣﺎ ﻣﻦ ﻟﻔﻦ ﻋﻠﻰ ﺍﻟﺴﺎﺧﻦ ﻣﺜﻞ ﺍﻟـﺼﻠﺐ‬ ‫ﺍﻟﻄﺮﻯ ﺍﻟﻌﺎﺩﻯ ﺍﻷﻣﻠﺲ ﻭﺍﻟﺼﻠﺐ ﻋﺎﱃ ﺍﳌﻘﺎﻭﻣﺔ ﺫﻭ ﻧﺘﺆﺍﺕ‪ ،‬ﺃﻭ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﳌﻌﺎﰿ ﻋﻠﻰ ﺍﻟﺒـﺎﺭﺩ ﻣﺜـﻞ‬ ‫ﺍﻷﺳﻼﻙ ﺫﺍﺕ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻌﺎﻟﻴﺔ ﺍﳌﺴﺘﺨﺪﻣﺔ ﰱ ﺍﳋﺮﺳﺎﻧﺔ ﺳﺎﺑﻘﺔ ﺍﻹﺟﻬﺎﺩ‪ .‬ﻭﺳﻮﻑ ﻳﺘﻢ ﺫﻛﺮ ﺇﺷـﺘﺮﺍﻃﺎﺕ‬ ‫ﺻﻼﺣﻴﺔ ﻛﻞ ﻣﻨﻬﺎ ﻋﻠﻰ ﺣﺪﻩ ﻭﺫﻟﻚ ﺑﺎﻟﻨـﺴﺒﺔ ﻟﻠﺨـﻮﺍﺹ ﺍﻟﻜﻴﻤﻴﺎﺋﻴـﺔ ﻭﺍﳌﻴﻜﺎﻧﻴﻜﻴـﺔ ﻭﺍﻟﺘﺠـﺎﻭﺯﺍﺕ‬ ‫ﻭﺍﻟﺜﻘﺎﻭﻣﺎﺕ ﺍﳌﺴﻤﻮﺡ ‪‬ﺎ ﰱ ﺃﺑﻌﺎﺩ ﻭﺃﻭﺍﺯﺍﻥ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ‪.‬‬

‫‪١٣٥‬‬


‫‪ ١-٧-٣-٧‬ا‪ %‬ا‪$‬ت "! أخ ا ا ا ا ‬ ‫أ‪ -‬ا آ وا )اص ا'&‪:‬‬ ‫ﻳﺒﲔ ﺟﺪﻭﻝ )‪(١-٧‬ﺣﺪﻭﺩ ﺍﳌﻮﺍﺻﻔﺎﺕ ﻟﻠﺘﺮﻛﻴﺐ ﻭﺍﳋﻮﺍﺹ ﺍﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﻟﺮﺗﺐ ﻭﻧﻮﻋﻴﻪ ﺃﺳﻴﺎﺥ ﺍﻟـﺼﻠﺐ‬ ‫ﺍﳌﺪﻟﻔﻨﻪ ﻋﻠﻰ ﺍﻟﺴﺎﺧﻦ‪.‬‬ ‫‪@ @|îÜnÛa@kÜ–Û@òîöbîàîØÛa@ãìäë@kî×ÜÛ@pbÐ•aì½a@…ë†yHQMWI@Þë†u‬‬

‫‪@ @pbÐ•aì½a@…ë†y‬‬

‫‪@ @òî•bä‬‬

‫‪@ @òÐÜn‚½a@†í†§a@kmŠÛ@Hó–Óc@†yI@òíì÷½a@òjäÛa‬‬ ‫‪@ @Š–äÈÛa‬‬

‫•‪@ë‡@òßëbÔ½a@µbÇ@kÜ‬‬ ‫•‪@ @Üßc@ô…bÇ@ôŠ@kÜ‬‬ ‫‪@ @paûnã‬‬

‫‪٣٥/٢٤‬‬ ‫‪٤٥/٢٨‬‬

‫‪٥٢/٢٦‬‬ ‫‪٦٠/٤٠‬‬

‫×‪@ @æìiŠ‬‬

‫‪٠,٢٥‬‬

‫‪٠,٤٠‬‬

‫×‪@ @oí‬‬

‫‪٠,٠٥٥‬‬

‫‪٠,٠٥٥‬‬

‫‪@ @‰ìÐìÏ‬‬

‫‪٠,٠٥٥‬‬

‫‪٠,٠٥٥‬‬

‫×‪@ @æìiŠ‬‬

‫‪٠,٣٠‬‬

‫‪٠,٤٥‬‬

‫×‪@ @oí‬‬

‫‪٠,٠٦٠‬‬

‫‪٠,٦٠‬‬

‫‪@ @‰ìÐìÏ‬‬

‫‪٠,٠٦٠‬‬

‫‪٠,٠٦٠‬‬

‫‪@kÜ–ÜÛ@óöbîàîØÛa@kî×Ûa‬‬ ‫‪@ @Hòj–Ûa@I@ÝöbÛa‬‬

‫‪@wnäàÜÛ@óöbîàîØÛa@kî×Ûa‬‬ ‫‪@ @H„bîþaI@óöbèäÛa‬‬

‫ب‪ -‬ا )اص ا'' ‪-:.‬‬ ‫ﻳﺒﲔ ﺟﺪﻭﻝ )‪ (٢-٧‬ﺍﳊﺪ ﺍﻷﺩﱏ ﻟﻠﺨﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻟﻠﺸﺪ ﺍﻻﺳﺘﺎﺗﻴﻜﻰ ﻭﺍﻟﺜﲎ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻟـﺼﻠﺐ‬ ‫ﺍﻟﺘﺴﻠﻴﺢ ﻭﺍﻟﱴ ﺇﺳﺘﻴﻔﺎﺋﻬﺎ ﻋﻨﺪ ﺍﻻﺳﺘﺨﺪﺍﻡ‪.‬‬ ‫ ﳚﺮﻯ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺸﺪ ﻋﻠﻰ ﻋﻴﻨﺔ ﺍﺧﺘﺒﺎﺭ ﻣﻦ ﺍﻷﺳﻴﺎﺥ ﺍﳌﻌﺪﺓ ﻟﻼﺳﺘﻌﻤﺎﻝ ﺑﺪﻭﻥ ﺃﻥ ﺗﺘﻌﺮﺽ ﻷﻳﺔ ﻣﻌﺎﳉﺔ‬ ‫ﺣﺮﺍﺭﻳﺔ ﻭﳚﻮﺯ ﺍﺳﺘﻌﺪﺍﻝ ﺍﻟﻌﻴﻨﺔ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﰱ ﺣﺎﻟﺔ ﺍﻻﻋﻮﺟﺎﺝ ﺍﻟﺒﺴﻴﻂ ﻋﻠﻰ ﺃﻥ ﺗﺸﻜﻞ ﺍﻟﻌﻴﻨـﺎﺕ‬ ‫ﻃﺒﻘﺎ ﻟﺸﻜﻠﻬﺎ ﻭﺃﺑﻌﺎﺩﻫﺎ ﺍﻟﻘﻴﺎﺳﻴﺔ‪.‬‬ ‫ ﳚﺮﻯ ﺍﺧﺘﺒﺎﺭ ﺷﺪ ﻭﺍﺣﺪ ﻋﻠﻰ ﺍﻷﻗﻞ ﻟﻜﻞ ﳎﻤﻮﻋﺔ ﻣﻦ ﺍﻷﺳﻴﺎﺥ ﺗﺰﻥ ‪ ١٠‬ﻃﻦ ﺃﻭ ﺃﻗـﻞ ﻭﰱ ﺣﺎﻟـﺔ‬ ‫ﺗﻌﺪﺩ ﻣﻘﺎﺳﺎﺕ ﻣﻘﺎﻃﻊ ﺍﻷﺳﻴﺎﺥ ﰱ ﺍ‪‬ﻤﻮﻋﺔ ﳚﺮﻯ ﺍﺧﺘﺒﺎﺭ ﺷﺪ ﻭﺍﺣﺪ ﻋﻠﻰ ﺍﻷﻗﻞ ﻟﻜﻞ ﻣﻘﺎﺱ ﻣﻨﻬﺎ‪.‬‬

‫‪١٣٦‬‬


‫‪@ @|îÜnÛa@kÜ–Û@…‰bjÛa@óÜÇ@óärÛaë@óØîmbnüa@†’ÜÛ@òîØîãbØî½a@ãì‚ÜÛ@óã…þa@†§a@HRMWI@Þë†u‬‬ ‫‪@ @òî•bä‬‬ ‫‪@ãìä‬‬ ‫‪@ @òîØîãbØî½a‬‬

‫‪@ @pbÐ•ì½a@…ë†y‬‬ ‫ﺇﺟﻬﺎﺩ ﺍﳋﻀﻮﻉ‬ ‫ﺍﻟﺮﺗﺒﺔ‬

‫) ﺇﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ(‬

‫ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﺍﻟﻘﺼﻮﻯ‬

‫ﻛﺠﻢ‪/‬ﻣﻢ‪) ٢‬ﺣﺪ ﺃﺩﱏ(‬ ‫‪٣٥/٢٤‬‬

‫ﻛﺠﻢ‪/‬ﻣﻢ‪٢‬‬

‫‪٢٤‬‬


‫ﻩ‬

‫ﺍﻟﺜﲎ ﺍﳌﻔﺮﺩ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ )‪( ١٨٠‬‬

‫)ﺣﺪ ﺃﺩﱏ (‬

‫ﺍﻟﻘﻄﺮ ﻣﻢ‬

‫ﻗﻄﺮ ﺍﻟﺪﻭﺭﺍﻥ‬

‫> ‪٢٥‬‬

‫‪٢‬ﻕ‬

‫< ‪٢٥‬‬

‫‪٣‬ﻕ‬

‫> ‪٢٥‬‬

‫‪٢‬ﻕ‬

‫< ‪٢٥‬‬

‫‪٣‬ﻕ‬

‫> ‪٢٠‬‬

‫‪٤‬ﻕ‬

‫<‪٣٦>٢٠‬‬

‫‪٥‬ﻕ‬

‫< ‪٣٦‬‬

‫‪--‬‬

‫> ‪٢٠‬‬

‫‪٤‬ﻕ‬

‫<‪٢٥>٢٠‬‬

‫‪٥‬ﻕ‬

‫<‪٣٦>٢٥‬‬

‫‪٦‬ﻕ‬

‫< ‪٣٦‬‬

‫‪--‬‬

‫ﻝ = ‪ ١٠‬ﻕ‬ ‫‪٢٠‬‬

‫‪٣٥‬‬

‫•‪@ôŠ@kÜ‬‬ ‫‪٤٥/٢٨ @ @Üßc@ô…bÇ‬‬

‫‪٢٨‬‬

‫‪٤٥‬‬

‫‪١٨‬‬

‫‪٥٢/٣٦‬‬

‫‪٣٦‬‬

‫‪٥٢‬‬

‫‪١٢‬‬

‫•‪@µbÇ@kÜ‬‬ ‫‪@ë‡@òßëbÔ½a‬‬

‫‪٦٠/٤٠‬‬

‫‪٤٠‬‬

‫‪١٠‬‬

‫‪٦٠‬‬

‫‪@ @paûnã‬‬

‫ﺣﻴﺚ ﻝ = ﻃﻮﻝ ﺍﻟﻘﻴﺎﺱ )ﻣﻢ(‬

‫ﻕ = ﻗﻄﺮ ﻋﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ )ﻣﻢ(‬

‫‪0‬ـ‪ -‬أ‪23‬د ا‪6‬ات ا‪ 2‬ا‪5‬و‪4‬‬ ‫ﻳﺒﲔ ﺍﳉﺪﻭﻝ )‪ (٣-٧‬ﺣﺪﻭﺩ ﺍﳌﻮﺻﻔﺎﺕ ﻷﺑﻌﺎﺩ ﺍﻟﻨﺘﺆﺍﺕ ﻟﻠﺼﻠﺐ ﺍﻟﻌﺎﱃ ﺍﳌﻘﺎﻭﻣﺔ ﻭﺃﺑﻌـﺎﺩ ﺍﻟﻨﺘـﺆﺍﺕ ﰱ‬ ‫ﺍﻻﲡﺎﻩ ﺍﻟﻄﻮﱃ ﻭﺍﻟﻌﺮﺿﻰ ﻟﻠﺴﻴﺦ‪.‬‬ ‫‪@ @paûnäÛa@…bÈiþ@pbÐ•ì½a@Þë†u@HSMWI@Þë†u‬‬ ‫‪@ @pbÐ•aì½a@Þë†u‬‬

‫‪@ @òî•bä‬‬

‫ﻻ ﺗﺰﻳﺪ ﺯﺍﻭﻳﺔ ﻣﻴﻞ ﺍﻟﻨﺘﺆ ﺍﻟﻄﻮﱃ ﻋﻠﻰ ﺍﶈﻮﺭ ﺍﻟﺮﺃﺳﻰ ﻟﻠﺴﻴﺦ ﻋﻠﻰ ‪ ٤٥‬ﺩﺭﺟﺔ‪.‬‬ ‫‪ @ @paûnäÛa@pba‘a‬ﻻ ﺗﺰﻳﺪ ﺍﳌﺴﺎﻓﺔ ﺑﲔ ﺃﻯ ﻧﺘﺆ ﺑﲔ ﻋﺮﺿﲔ ﻋﻠﻰ ‪ %٧٠‬ﻣﻦ ﺍﻟﻘﻄﺮ ﺍﳌﻜﺎﻓﺊ ﺍﻻﲰـﻰ‬ ‫ﻟﻠﺴﻴﺦ‪.‬‬ ‫ﻻ ﻳﻘﻞ ﺍﺭﺗﻔﺎﻉ )ﻉ( ﻋﻦ ‪ %٥‬ﻣﻦ ﺍﻟﻘﻄﺮ ﺍﳌﻜﺎﻓﺊ ﺍﻻﲰﻰ ﻟﻠﺴﻴﺦ ﻭﺫﻟﻚ ﻟﻸﺳﻴﺎﺥ‬ ‫ﺫﺍﺕ ﻗﻄﺮ ﻣﻜﺎﻓﺊ ﺍﲰﻰ ﻻ ﻳﺰﻳﺪ ﻋﻠﻰ ‪١٦‬ﻣﻢ ﺃﻣﺎ ﰱ ﺣﺎﻟﺔ ﺍﻷﺳﻴﺎﺥ ﺍﻟﱴ ﻳﺰﻳﺪ ﻗﻄﺮﻫﺎ‬ ‫‪@ @paûnäÛa@pba‘a‬‬

‫ﺍﳌﻜﺎﻓﺊ ﺍﻻﲰﻰ ﻋﻠﻰ ‪ ١٦‬ﻣﻢ ﻓﲑﺍﻋﻰ ﺃﻻ ﺗﻘﻞ ﺍﺭﺗﻔﺎﻉ ﺍﻟﻨﺘﺆ )ﻉ( ﻋـﻦ ‪ %٦‬ﻣـﻦ‬ ‫ﺍﻟﻘﻄﺮ ﺍﳌﻜﺎﻓﺊ ﺍﻻﲰﻰ‪.‬‬ ‫ﻻ ﻳﺰﻳﺪ ﳎﻤﻮﻉ ﺍﳌﺴﺎﻓﺎﺕ ﺍﳋﺎﻟﻴﺔ ﻣﻦ ﺍﻟﻨﺘﺆﺍﺕ ﻋﻠﻰ ‪ %٢٥‬ﻣﻦ ﺍﶈـﻴﻂ ﺍﻻﲰـﻰ‬ ‫ﻟﻠﺴﻴﺦ ﰱ ﲨﻴﻊ ﺍﳊﺎﻻﺕ‪.‬‬ ‫‪١٣٧‬‬


‫د‪ -‬ا;وزان و‪ 4‬ا‪85‬ع‬ ‫ﻳﺒﲔ ﺍﳉﺪﻭﻝ ﺍﻟﺘﺎﱃ )‪ (٤-٧‬ﲨﻴﻊ ﺃﻗﻄﺎﺭ ﻭﺃﻭﺯﺍﻥ ﻭﻣﺴﺎﺣﺔ ﻣﻘﻄﻊ ﺣﺪﻳﺪ ﺍﻟﺼﻠﺐ ﺍﳌﺴﺘﻌﻤﻞ ﰱ ﺍﳋﺮﺳﺎﻧﺔ‬ ‫ﺍﳌﺴﻠﺤﺔ ﰱ ﻣﺼﺮ ﻭﻋﺪﺓ ﺩﻭﻝ ﺃﺧﺮﻯ ﻣﻦ ﺍﻟﻌﺎﱂ‪.‬‬ ‫‪@ @|îÜnÛa@†í†y@ÉĐÔß@òybßë@æa‹ëcë@‰bĐÓc@HTMWI@Þë†u‬‬ ‫‪Area of Cross – section in cm2‬‬

‫‪Weight‬‬

‫‪Φ‬‬

‫‪Kg/m‬‬

‫‪mm‬‬ ‫‪5‬‬

‫‪10‬‬

‫‪9‬‬

‫‪8‬‬

‫‪7‬‬

‫‪6‬‬

‫‪5‬‬

‫‪4‬‬

‫‪3‬‬

‫‪2‬‬

‫‪1‬‬

‫‪1.96‬‬

‫‪1.77‬‬

‫‪1.57‬‬

‫‪1.37‬‬

‫‪1.18‬‬

‫‪0.982‬‬

‫‪0.785‬‬

‫‪0.589‬‬

‫‪0.393‬‬

‫‪0.196‬‬

‫‪0.154‬‬

‫‪2.83‬‬

‫‪2.54‬‬

‫‪2.26‬‬

‫‪1.98‬‬

‫‪1.70‬‬

‫‪1.41‬‬

‫‪1.13‬‬

‫‪0.848‬‬

‫‪0.566‬‬

‫‪0.283‬‬

‫‪0.222‬‬

‫‪6‬‬

‫‪3.85‬‬

‫‪3.46‬‬

‫‪3.08‬‬

‫‪2.69‬‬

‫‪2.31‬‬

‫‪1.93‬‬

‫‪1.54‬‬

‫‪1.15‬‬

‫‪0.770‬‬

‫‪0.385‬‬

‫‪0.302‬‬

‫‪7‬‬

‫‪5.03‬‬

‫‪4.52‬‬

‫‪4.02‬‬

‫‪3.52‬‬

‫‪3.02‬‬

‫‪2.51‬‬

‫‪2.01‬‬

‫‪1.51‬‬

‫‪1.01‬‬

‫‪0.503‬‬

‫‪0.395‬‬

‫‪8‬‬

‫‪7.85‬‬

‫‪7.07‬‬

‫‪6.28‬‬

‫‪5.50‬‬

‫‪4.71‬‬

‫‪3.93‬‬

‫‪3.14‬‬

‫‪2.36‬‬

‫‪1.57‬‬

‫‪0.785‬‬

‫‪0.617‬‬

‫‪9‬‬

‫‪11.30‬‬

‫‪1.02‬‬

‫‪9.05‬‬

‫‪7.92‬‬

‫‪6.79‬‬

‫‪5.65‬‬

‫‪4.52‬‬

‫‪3.39‬‬

‫‪2.26‬‬

‫‪1.13‬‬

‫‪0.888‬‬

‫‪10‬‬

‫‪13.30‬‬

‫‪11.9‬‬

‫‪10.6‬‬

‫‪9.29‬‬

‫‪7.96‬‬

‫‪6.64‬‬

‫‪5.31‬‬

‫‪3.98‬‬

‫‪2.66‬‬

‫‪1.33‬‬

‫‪1.04‬‬

‫‪12‬‬

‫‪15.4‬‬

‫‪13.9‬‬

‫‪12.3‬‬

‫‪10.8‬‬

‫‪4.24‬‬

‫‪7.70‬‬

‫‪6.16‬‬

‫‪4.62‬‬

‫‪3.08‬‬

‫‪1.54‬‬

‫‪1.21‬‬

‫‪13‬‬

‫‪20.1‬‬

‫‪18.1‬‬

‫‪16.1‬‬

‫‪14.1‬‬

‫‪12.1‬‬

‫‪10.1‬‬

‫‪8.04‬‬

‫‪6.03‬‬

‫‪4.02‬‬

‫‪2.01‬‬

‫‪1.58‬‬

‫‪14‬‬

‫‪25.4‬‬

‫‪22.9‬‬

‫‪20.4‬‬

‫‪17.8‬‬

‫‪15.3‬‬

‫‪12.70‬‬

‫‪10.2‬‬

‫‪7.63‬‬

‫‪5.09‬‬

‫‪2.54‬‬

‫‪2.00‬‬

‫‪16‬‬

‫‪28.4‬‬

‫‪25.5‬‬

‫‪22.7‬‬

‫‪19.9‬‬

‫‪17.0‬‬

‫‪14.2‬‬

‫‪11.30‬‬

‫‪8.50‬‬

‫‪5.67‬‬

‫‪2.835‬‬

‫‪2.23‬‬

‫‪18‬‬

‫‪31.4‬‬

‫‪28.3‬‬

‫‪25.1‬‬

‫‪22.0‬‬

‫‪18.8‬‬

‫‪15.7‬‬

‫‪12.6‬‬

‫‪9.42‬‬

‫‪6.28‬‬

‫‪3.14‬‬

‫‪2.47‬‬

‫‪20‬‬

‫‪38.0‬‬

‫‪34.2‬‬

‫‪30.4‬‬

‫‪26.6‬‬

‫‪22.8‬‬

‫‪19.0‬‬

‫‪15.2‬‬

‫‪11.4‬‬

‫‪7.60‬‬

‫‪3.80‬‬

‫‪2.98‬‬

‫‪22‬‬

‫‪45.2‬‬

‫‪40.7‬‬

‫‪36.2‬‬

‫‪31.7‬‬

‫‪27.0‬‬

‫‪22.6‬‬

‫‪18.1‬‬

‫‪13.6‬‬

‫‪9.04‬‬

‫‪4.52‬‬

‫‪3.55‬‬

‫‪24‬‬

‫‪49.1‬‬

‫‪44.2‬‬

‫‪39.3‬‬

‫‪34.4‬‬

‫‪29.5‬‬

‫‪24.5‬‬

‫‪19.6‬‬

‫‪14.7‬‬

‫‪9.82‬‬

‫‪4.91‬‬

‫‪3.85‬‬

‫‪25‬‬

‫‪53.1‬‬

‫‪47.0‬‬

‫‪42.5‬‬

‫‪37.2‬‬

‫‪31.9‬‬

‫‪26.5‬‬

‫‪21.2‬‬

‫‪15.9‬‬

‫‪10.6‬‬

‫‪5.31‬‬

‫‪4.17‬‬

‫‪26‬‬

‫‪61.6‬‬

‫‪55.4‬‬

‫‪49.3‬‬

‫‪43.1‬‬

‫‪37.0‬‬

‫‪30.8‬‬

‫‪24.6‬‬

‫‪18.5‬‬

‫‪12.3‬‬

‫‪6.16‬‬

‫‪4.83‬‬

‫‪28‬‬

‫‪70.7‬‬

‫‪63.6‬‬

‫‪56.6‬‬

‫‪49.5‬‬

‫‪42.4‬‬

‫‪35.3‬‬

‫‪28.3‬‬

‫‪21.2‬‬

‫‪14.1‬‬

‫‪7.07‬‬

‫‪5.55‬‬

‫‪30‬‬

‫‪80.4‬‬

‫‪72.4‬‬

‫‪64.3‬‬

‫‪56.3‬‬

‫‪48.3‬‬

‫‪40.2‬‬

‫‪32.2‬‬

‫‪24.1‬‬

‫‪16.1‬‬

‫‪8.04‬‬

‫‪6.31‬‬

‫‪32‬‬

‫‪90.8‬‬

‫‪81.7‬‬

‫‪72.6‬‬

‫‪53.6‬‬

‫‪54.5‬‬

‫‪45.4‬‬

‫‪36.3‬‬

‫‪27.2‬‬

‫‪18.20‬‬

‫‪9.08‬‬

‫‪7.13‬‬

‫‪34‬‬

‫‪102‬‬

‫‪91.8‬‬

‫‪81.6‬‬

‫‪71.4‬‬

‫‪61.2‬‬

‫‪50.7‬‬

‫‪40.8‬‬

‫‪30.6‬‬

‫‪20.4‬‬

‫‪10.02‬‬

‫‪7.99‬‬

‫‪36‬‬

‫‪113‬‬

‫‪102‬‬

‫‪90.4‬‬

‫‪79.1‬‬

‫‪67.8‬‬

‫‪56.5‬‬

‫‪45.2‬‬

‫‪33.9‬‬

‫‪22.6‬‬

‫‪11.3‬‬

‫‪8.90‬‬

‫‪38‬‬

‫‪١٣٨‬‬


‫هـ‪ -‬ا‪B‬وزات واوت ا)ح ‪ @ 3‬أ‪23‬د وأ‪)$‬ل ووزن > ا‪:‬‬ ‫ﻳﺒﲔ ﺍﳉﺪﻭﻝ )‪ (٥-٧‬ﺍﳊﺪﻭﺩ ﺍﳌﺴﻤﻮﺡ ‪‬ﺎ ﻟﻠﺘﺠﺎﻭﺯﺍﺕ ﰱ ﺃﺑﻌﺎﺩ ﻭﺃﻃﻮﺍﻝ ﻭﻭﺯﻥ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ‪.‬‬ ‫‪@ @|îÜnÛa@†í†y@æ‹ëë@Þaìcë@…bÈic@óÏ@pa‹ëbvnÜÛ@bèi@ìà½a@…ë†§a@HUMWI@Þë†u‬‬

‫‪@ @pbÐ•ì½a@…ë†y‬‬

‫‪@ @òî•bä‬‬

‫ﻻ ﻳﺰﻳﺪ ﺍﻟﻔﺮﻕ ﺑﲔ ﻃﻮﱃ ﺃﻯ ﻗﻄﺮﻳﻦ ﻣﺘﻌﺎﻣﺪﻳﻦ ﻣﻘﺎﺳﲔ ﻋﻨﺪ ﻧﻔﺲ ﺍﳌﻘﻄﻊ ﻋﻦ ‪ %٨‬ﻣﻦ‬ ‫‪@óÏ@bèi@ìà½a@pa‹ëbvnÛa‬‬

‫ﺍﻟﻘﻴﻤﺔ ﺍﻷﲰﻴﺔ ﻟﻠﻘﻄﺮ‪.‬‬

‫‪@ @ÉĐÔàÜÛ@òÐÜn‚½a@…bÈiþa‬‬

‫ﻻ ﻳﺰﻳﺪ ﺍﻟﺘﺠﺎﻭﺯ ﰱ ﻣﻘﺎﺱ ﺍﻟﻘﻄﺮ ‪٠,٥ +‬ﻣﻢ ﻭﺫﻟﻚ ﻟﻸﻗﻄﺎﺭ ﺍﻷﲰﻴﺔ ﺣﱴ ‪٢٥‬ﻣﻢ ‪+‬‬ ‫‪١,٠٠‬ﻣﻢ ﻟﻸﻗﻄﺎﺭ ﺍﻷﲰﻴﺔ ﺍﻷﻛﱪ ﻣﻦ ‪٢٥‬ﻣﻢ‪.‬‬ ‫ﺍﻟﺘﺠﺎﻭﺯﺍﺕ ﰱ ﻭﺯﻥ ﺍﳌﺘﺮ ﺍﻟﻄﻮﱃ ) ‪( %‬‬

‫ﺍﻟﻘﻄﺮ ﺍﻷﲰﻰ‬ ‫‪@óÏ@bèi@ìà½a@pa‹ëbvnÛa‬‬

‫)ﻣﻢ(‬

‫ﺍﻟﺮﺳﺎﻟﺔ‬

‫ﺍﻟﺴﻴﺦ ﺍﳌﻔﺮﺩ‬

‫‪@ @æa‹ëþa‬‬

‫‪٦‬‬

‫‪٦+‬‬

‫‪٨-‬‬

‫‪١٠ ، ٨‬‬

‫‪٤,٥٠ +‬‬

‫‪٦-‬‬

‫‪ ١٢‬ﻓﺄﻛﺜﺮ‬

‫‪٢,٥ +‬‬

‫‪٤-‬‬

‫ﻳﺴﻤﺢ ﺑﺘﺠﺎﻭﺯ ﰱ ﻃﻮﻝ ﺍﻟﺴﻴﺦ ﻗﺪﺭﺓ ‪ - ،٤٠ +‬ﺻﻔﺮ ﻭﺫﻟﻚ ﻟﻸﺳﻴﺎﺥ ﺍﻟﱴ ﻻ ﻳﺰﻳﺪ ﻃﻮﳍﺎ‬ ‫‪@óÏ@bèi@ìà½a@pa‹ëbvnÛa‬‬ ‫‪@ @Þaìþa‬‬

‫ﻋﻠﻰ ‪ ٦‬ﻣﺘﺮ‪.‬‬ ‫ﻳﺴﻤﺢ ﺑﺘﺎﺟﻮﺯ ﺃﻛﱪ ﻟﻸﺳﻴﺎﺥ ﺍﻟﱴ ﻳﺰﻳﺪ ﻃﻮﳍﺎ ﻋﻠﻰ ‪ ٦‬ﻣﺘﺮ ﲝﻴﺚ ﻳﻀﺎﻑ ﻟﻠﺘﺠﺎﻭﺯ ﺍﻟﺴﺎﺑﻖ‬ ‫‪٥‬ﻣﻢ ﻟﻜﻞ ﻣﺘﺮ ﺯﻳﺎﺩﺓ ﰱ ﺍﻟﻄﻮﻝ ﻋﻦ ‪ ٦‬ﻣﺘﺮ ﻋﻠﻰ ﺃﻻ ﻳﺰﻳﺪ ﺍﻟﺘﺠﺎﻭﺯ ﺍﻟﻜﻠﻰ ﻋﻠﻰ ‪ ١٢٠‬ﻣﻢ‬ ‫ﻣﻬﻤﺎ ﻛﺎﻥ ﻃﻮﻝ ﺍﻟﺴﻴﺦ‪.‬‬

‫‪ ٢-٧-٣-٧‬ا‪ DDDD%‬ا‪$‬ت "‪ !DDDD‬ا‪!DDDDG‬ك ذات ا‪5‬و‪ DDDD4‬ا‪ DDDD2‬ا‪DDDD@ 4 DDDD‬‬ ‫ا ‪ 53‬ا‪H0I‬د‪-:‬‬ ‫ ﺗﻌﺮﻳﻒ‪:‬‬ ‫ﺍﻟﺴﻠﻚ ﺫﻭ ﻣﻘﺎﻭﻣﺔ ﻋﺎﻟﻴﺔ ﻹﺟﻬﺎﺩ ﺍﻟﺸﺪ ﻫﻮ ﺳﻠﻚ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﳌﺴﺤﻮﺏ ﻋﻠـﻰ ﺍﻟﺒـﺎﺭﺩ ﻭﺫﻭ‬ ‫ﻣﻘﻄﻊ ﻣﺴﺘﺪﻳﺮ ﻭﺫﻟﻚ ﻟﻼﺳﺘﺨﺪﺍﻡ ﰱ ﺍﳋﺮﺳﺎﻧﺔ ﺳﺎﺑﻘﺔ ﺍﻻﺟﻬﺎﺩ‪.‬‬ ‫ ﻃﺮﻳﻘﺔ ﺍﻟﺼﻨﺎﻋﺔ‪:‬‬ ‫ﺗﺼﻨﻊ ﺍﻷﺳﻼﻙ ﻋﺎﻟﻴﺔ ﺍﳌﻘﺎﻭﻣﺔ ﺑﺴﺤﺒﻬﺎ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻣﻦ ﺍﻟﺼﻠﺐ ﻭﳚﺐ ﻋﻨـﺪ ﺍﺟـﺮﺍﺀ ﲢﻠﻴـﻞ‬ ‫ﻛﻤﻴﺎﺋﻰ ﳍﺬﻩ ﺍﻷﺳﻼﻙ ﺃﻻ ﻳﺰﻳﺪ ﻧﺴﺒﺔ ﺍﻟﻜﱪﻳﺖ ﻋـﻦ ‪ %٠,٠٥‬ﻭﻧـﺴﺒﺔ ﺍﻟﻔﻮﺳـﻔﻮﺭ ﻋـﻦ‬ ‫‪ %٠,٠٥‬ﻭﺃﻻ ﺗﺰﻳﺪ ﳎﻤﻮﻉ ﻧﺴﺒﱴ ﺍﻟﻜﱪﻳﺖ ﻭﺍﻟﻔﺴﻔﻮﺭ ﻋﻦ ‪.%٠,٠٩‬‬ ‫‪١٣٩‬‬


‫ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﻭﺇﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ ﻟﻠﺴﻠﻚ ﻋﺎﱃ ﺍﳌﻘﺎﻭﻣﺔ‬ ‫ﻳﺒﲔ ﺍﳉﺪﻭﻝ ﺍﻟﺘﺎﱃ )‪ (٦-٧‬ﺍﳌﻘﻮﻣﺔ ﺍﻟﻘﺼﻮﻯ ﻟﻠﺸﺪ ﻭﺇﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ ﻟﻜﻞ ﻗﻄﺮ ﻋﻠﻰ ﺣﺪﺓ‪.‬‬ ‫‪@ @òßëbÔ½a@µbÈÛa@ÙÜÜÛ@æbàšÛa@…bèugë@ôì–ÔÛa@òßìÔ½a@HVMWI@Þë†u‬‬

‫ﻗﻄﺮ ﺍﻟﺴﻠﻚ )ﻣﻢ(‬

‫ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ‬ ‫)ﻛﺠﻢ‪/‬ﻣﻢ‪(٢‬‬

‫‪ ٠,٠١‬ﺇﺟﻬﺎﺩ ﺍﻟﻀﻤﺎﻥ‬ ‫)ﻛﺠﻢ‪/‬ﻣﻢ‪(٢‬‬

‫‪٨‬‬

‫‪١٣٥‬‬

‫‪٩٥‬‬

‫‪٧‬‬

‫‪١٤٠‬‬

‫‪١٠٠‬‬

‫‪٦‬‬

‫‪١٤٥‬‬

‫‪١٠٥‬‬

‫‪٥‬‬

‫‪١٦٠‬‬

‫‪١١٥‬‬

‫‪٤‬‬

‫‪١٧٥‬‬

‫‪١٢٥‬‬

‫‪٣‬‬

‫‪١٩٠‬‬

‫‪١٣٥‬‬

‫‪٢‬‬

‫‪٢٠٥‬‬

‫‪١٤٥‬‬

‫‪١٤٠‬‬


‫‪Polymers 7'8( "( 4-7‬‬

‫‪@ @@òß†Ôß@QMTMW‬‬ ‫ ﺇﻥ ﻛﻠﻤﺔ ﺑﻮﻟﻴﻤﺮ ﻻﺗﻨﻴﺔ ﺍﻷﺻﻞ ﻭﻫﻰ ﻣﺮﻛﺒﺔ ﻣﻦ ﻣﻘﻄﻌﲔ ﳘﺎ‪:‬‬‫ ﺑﻮﱃ ) ‪ (poly‬ﻭﺗﻌﲎ ﻣﺘﻌﺪﺩ‪.‬‬‫ ﻣـﺮ )‪ (mer‬ﻭﺗﻌﲏ ﻭﺣﺪﺓ ﺃﻭ ﺟﺰﺀ‪.‬‬‫ﻟﺬﻟﻚ ﻓﺈﻥ ﺍﻟﺒﻮﻟﻴﻤﺮ )‪ (polymer‬ﺗﻌﲎ ﻣﺘﻌﺪﺩ ﺍﻟﻮﺣﺪﺍﺕ ﺃﻭ ﻣﺘﻌﺪﺩ ﺍﻷﺟﺰﺍﺀ‪ ،‬ﻭﻫﻮ ﻣﺮﻛـﺐ ﻛﻤﻴـﺎﺋﻰ‬ ‫ﺃﺳﺎﺳﻪ ﺍﻟﻜﺮﺑﻮﻥ ﻭﺍﻷﻛﺴﺠﲔ ﻭﺍﳍﻴﺪﺭﻭﺟﲔ ﻭﺍﻟﻨﻴﺘﺮﻭﺟﲔ ﻭﺍﳌﻮﺟﻮﺩﺓ ﰱ ﺍﳌﺎﺀ ﻭﺍﳍﻮﺍﺀ ﻭﺍﳌﺼﺎﺩﺭ ﺍﻟﻨﺒﺎﺗﻴـﺔ‬ ‫ﻭﺍﳊﻴﻮﺍﻧﻴﺔ ﻭﺍﻟﻔﺤﻢ ﺍﻟﺒﺘﺮﻭﻝ‪.‬‬ ‫ ﻭﻋﺮﻑ ﺍﻹﻧﺴﺎﻥ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﻣﻨﺬ ﺍﻟﻘﺪﻡ ﻭﺍﺳﺘﺨﺪﺍﻡ ﺍﳌﻨﺘﺠﺎﺕ ﺍﻟﻨﺒﺎﺗﻴﺔ ﻭﺍﳊﻴﻮﺍﻧﻴﺔ ﺍﻟﺒﺔﳌﲑﻳﺔ ﻷﻏﺮﺍﺽ‬‫ﳐﺘﻠﻔﺔ ﰱ ﺣﻴﺎﺗﻪ ﺍﻟﻴﻮﻣﻴﺔ‪ ،‬ﻓﻘﺪ ﺍﺳﺘﺨﺪﻡ ﺍﻹﻧﺴﺎﻥ ﺍﻟﻘﺎﺭ ﻭﺍﻟﺮﺍﺗﻨﺠﺎﺕ )‪ (resin‬ﺍﻟﻨﺒﺎﺗﻴﺔ ﻓﻌﺮﻑ ﺍﻟﺼﻤﻎ‬ ‫ﻭﺍﳌﻄﺎﻁ ﻣﻨﺬ ﺁﻻﻑ ﺍﻟﺴﻨﲔ‪ .‬ﻭﺍﻵﻥ ﺗﻌﺪ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﻟﻌﻀﻮﻳﺔ ﺫﺍﺕ ﺃﳘﻴﺔ ﺑﺎﻟﻐﺔ ﰱ ﺣﻴﺎﺓ ﺍﻻﻧﺴﺎﻥ ﺇﺫ‬ ‫ﺗﺪﺧﻞ ﰱ ﺍﻟﻮﻗﺖ ﺍﳊﺎﺿﺮ ﰱ ﻣﻜﻮﻧﺎﺕ ﻏﺬﺍﺋﻪ ﻭﻛﺴﺎﺋﻪ ﻭﻣﺴﻜﻨﻪ‪ ،‬ﻓﻴﻨﺘﺞ ﻣﻦ ﺍﻟﻨﺸﻮﻳﺎﺕ ﻭﺍﻟﺴﻜﺮﻳﺎﺕ‬ ‫ﻭﺍﻟﱪﻭﺗﻴﻨﺎﺕ ﰱ ﺍﻟﻐﺬﺍﺀ‪ ،‬ﻭﻳﺴﺘﺨﺪﻡ ﺍﻟﻘﻄﻦ ﻭﺍﻟﺼﻮﻑ ﻭﺍﳊﺮﻳﺮ ﻭﺟﻠﻮﺩ ﺍﳊﻴﻮﺍﻧﺎﺕ ﰱ ﺻﻨﻊ ﺍﳌﻼﺑﺲ‪،‬‬ ‫ﻛﻤﺎ ﻳﺴﺘﻔﺎﺩ ﻣﻦ ﺍﳋﺸﺐ ﰱ ﺗﺸﻴﻴﺪ ﺍﳌﺒﺎﱏ ﻭﺍﳌﻨﺸﺂﺕ ﻭﺍﻵﺛﺎﺛﺎﺕ ﻭﻳﺴﺘﺨﺪﻡ ﺍﳌﻄﺎﻁ ﻭﺍﻟﺼﻤﻎ ﻭﻏﲑﻫﺎ‬ ‫ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﻟﺒﻮﻟﻴﻤﺮﻳﺔ ﺍﻟﱴ ﲣﺺ ﰱ ﺃﻏﺮﺍﺽ ﺷﱴ ﻣﺘﻌﺪﺩﺓ‪.‬‬ ‫ ﻭﻗﺪ ﺣﻠﺖ ﺑﻌﺾ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﶈﻀﺮﺓ ﺻﻨﺎﻋﻴﺎ ﰱ ﺍﻵﻭﻧﺔ ﺍﻷﺧﲑﺓ ﻣﻜﺎﻥ ﺍﳌﻮﺍﺩ ﺍﻟﻄﺒﻴﻌﻴﺔ ﻭﻫﺬﺍ ﻧـﺎﺗﺞ‬‫ﻋﻦ ﺍﻟﺘﻄﻮﺭ ﺍﳍﺎﺋﻞ ﺍﻟﺬﻯ ﺣﺪﺙ ﰱ ﺍﻟﺼﻨﺎﻋﺎﺕ ﺍﻟﻜﻤﻴﺎﻭﻳﺔ ﻭﺍﳌﻌﺘﻤﺪﺓ ﻋﻠﻰ ﺍﻟﻨﻔﻂ ﻭﻣﺸﺘﻘﺎﺗﻪ‪ ،‬ﻭﻫـﺬﻩ‬ ‫ﲤﻴﺰ ﺑﺼﻔﺎﺕ ﻣﻴﻜﺎﻧﻴﻜﻴﺔ ﺟﻴﺪﺓ ﻛﻤﺎ ﺗﺘﻤﻴﺰ ﺑﺮﺧﺺ ﺍﻟﺜﻤﻦ ﻭﺗﻮﻓﺮﻫـﺎ ﻭﺑـﺸﻜﻞ ﻛـﺒﲑ‪ ،‬ﻭﻗـﺪ ﰎ‬ ‫ﺇﺳﺘﺨﺪﺍﻣﻬﺎ ﰱ ﺻﻨﺎﻋﺔ ﺍﻷﺩﻭﺍﺕ ﺍﳌﱰﻟﻴﺔ ﻭﺍﻟﺼﻨﺎﻋﺎﺕ ﺍﳊﺮﺑﻴﺔ ﻭﺍﳌﺪﻧﻴﺔ ﻛﺎﻟـﺴﻴﺎﺭﺍﺕ ﻭﺍﻟﻄـﺎﺋﺮﺍﺕ‬ ‫ﻭﺍﻟﻐﻮﺻﺎﺕ ﻭﺍﻷﺟﻬﺰﺓ ﺍﻟﻜﻬﺮﺑﻴﺔ‪ .‬ﻭﰱ ﳎﺎﻝ ﺍﳌﻨﺸﺂﺕ ﺍﳋﺮﺳﺎﻧﻴﺔ ﻭﺍﻵﻥ ﳓﻦ ﺃﻣﺎﻡ ﺛـﻮﺭﺓ ﺻـﻨﺎﻋﻴﺔ‬ ‫ﺿﺨﻤﺔ ﻭﻫﺎﺋﻠﺔ ﺣﻴﺚ ﺃﻧﻪ ﺑﺎﻹﺿﺎﻓﺔ ﺇﱃ ﺍ‪‬ﺎﻻﺕ ﺍﻟﺴﺎﺑﻘﺔ ﲤﻜﻦ ﺍﻟﻌﻠﻤﺎﺀ ﻣﻦ ﻭﺿﻊ ﺁﻟﻴﺔ ﲤﻜـﻦ ﻣـﻦ‬ ‫ﺍﻻﺳﺘﻔﺎﺩﺓ ﻣﻦ ﺍﻟﺒﻮﻟﻴﻤﲑﺍﺕ ﰱ ﳎﺎﻝ ﺍﻟﺘﻮﺻﻴﻞ ﺍﻟﻜﻬﺮﺑﺎﺋﻰ ﻭﺑﺎﻷﺧﺺ ﰱ ﳎﺎﻝ ﺗـﺼﻨﻴﻊ ﺍﻟﺒﻄﺮﻳـﺎﺕ‬ ‫ﺍﻟﻜﻬﺮﺑﺎﺋﻴﺔ‪.‬‬

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‫ ﺑﺄﻧﻪ ﺟﺰﺉ ﳌﺮﻛﺐ ﻛﻴﻤﻴﺎﺋﻰ ﻳﺘﻤﺜﻞ ﺑﻮﺯﻥ ﺟﺰﻳﺌﻰ ﻋﺎﱃ ﻭﻣﺮﺗﻔﻊ ﻗﺪ ﻳﺘﺮﻭﺍﺡ ﻣـﺎ ﺑـﲔ‬ ‫‪@ àîÛì;jÛa@ÒŠÈí‬‬ ‫ﻋﺸﺮﺓ ﺍﻵﻻﻑ ﺇﱃ ﻋﺸﺮﺓ ﻣﻼﻳﲔ‪ ،‬ﻟﺬﻟﻚ ﻗﺪ ﻳﺴﻤﻰ ﺍﻟﺒﻮﻟﻴﻤﺮ ﰱ ﺑﻌﺾ ﺍﻷﺣﻴـﺎﻥ ﺑـﺎﳉﺰﺉ ﺍﻟﻌﻤـﻼﻕ‬ ‫)‪ .(Macromolecule‬ﻭﺟﺰﺉ ﺍﻟﺒﻮﻟﻴﻤﲑ ﻫﺬﺍ ﻳﻜﻮﻥ ﻋﻠﻰ ﺷﻜﻞ ﺳﻠﺴﻠﺔ ﺣﻠﻘﺎ‪‬ﺎ ﻋﺒﺎﺭﺓ ﻋﻦ ﺟﺰﻳﺌـﺎﺕ‬ ‫ﳌﺮﻛﺐ ﻛﻤﻴﺎﺋﻰ ﺑﺴﻴﻂ ﻳﺴﻤﻰ ﻣﻮﳕﺮ )‪ (Monomer‬ﺫﻭ ﻭﺯﻥ ﺟﺰﻳﺌﻰ ﺿﻐﲑ ﻳﺘﻤﻴﺰ ﺑﺘﺮﻛﻴـﺐ ﺧـﺎﺹ‬ ‫ﺣﻴﺚ ﳝﻜﻨﻪ ﺍﻟﺘﻔﺎﻋﻞ ﻣﻊ ﺟﺰﺉ ﺁﺧﺮ ﻣﻦ ﻧﻮﻋﻪ ﺃﻭ ﻣﻊ ﺟﺰﺉ ﻣﺮﻛﺐ ﺁﺧﺮ ﻭﲢﺖ ﻇﺮﻭﻑ ﻣﻨﺎﺳﺒﺔ ﺑﺮﻭﺍﺑﻂ‬ ‫ﺗﺴﺎﳘﻴﺔ )‪ (Covalent Bond‬ﻟﺘﻜﻮﻳﻦ ﺳﻠﺴﻠﺔ ﺍﻟﺒـﻮﻟﻴﻤﺮ‪ .‬ﻭﻣـﻦ ﻫﻨـﺎ ﳝﻜـﻦ ﺃﻥ ﻧﺘﻮﺻـﻞ ﺇﱃ ﺃﻥ‬ ‫ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺃﻭ ﺍﻟﺮﺍﺗﻨﺠﺎﺕ ﻫﻮ ﺍﺳﻢ ﻭﺍﺣﺪ ﳌﻮﺍﺩ ﻋﻀﻮﻳﺔ ﺫﺍﺕ ﻭﺯﻥ ﺟﺰﺋﻲ ﻭﺃﻥ ﺍﳉﺰﺀ ﺍﻟﻮﺍﺣـﺪ ﻣﻨـﻬﺎ‬ ‫ﻳﺴﻤﻰ ﻣﻮﳕﺮ‪.‬‬ ‫‪@ @@paŠàîÛìjÛa@‰…b–ß@RMTMW‬‬ ‫ﳝﻜﻦ ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﺍﻟﺒﻮﻟﻴﻤﲑﺍﺕ ﻣﻦ ﻣﺼﺪﺭﻳﻦ ﺃﺳﺎﺳﻴﻴﲔ ﳘﺎ‪:‬‬ ‫‪@ @Natural Polymers@@@òîÈîjĐÛa@paŠàîÛìjÛa@MQ‬‬ ‫ﻭﻫﺬﻩ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﻣﺮﻛﺒﺎﺕ ﻣﺼﺪﺭﻫﺎ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﻟﻄﺒﻴﻌﻴﺔ ﺇﻣﺎ ﻣﻮﺍﺩ ﻧﺒﺎﺗﻴﺔ ﺃﻭ ﻣﻮﺍﺩ ﺣﻴﻮﺍﻧﻴﺔ‪ ،‬ﻣﺜﻞ ﻫـﺬﻩ‬ ‫ﺍﳌﻮﺍﺩ ﺍﳋﺸﺐ ﻭﺍﻟﻘﻄﻦ ﻭﺍﳌﻄﺎﻁ ﺍﻟﻄﺒﻴﻌﻰ ﻭﺍﻷﺻﻤﺎﻍ ﺍﻟﻨﺒﺎﺗﻴﺔ ﻭﻫﺬﻩ ﻣﻦ ﺍﳌﺼﺎﺩﺭ ﺍﻟﻨﺒﺎﺗﻴﺔ ﺍﻟﻄﺒﻴﻌﻴﺔ‪ ،‬ﻭﺃﻳﻀﺎ‬ ‫ﻣﻦ ﺍﳌﺼﺎﺩﺭ ﺍﳊﻴﻮﺍﻧﻴﺔ ﺍﻟﻄﺒﻴﻌﻴﺔ ﻳﻮﺟﺪ ﺍﻟﺼﻮﻑ ﻭﺍﳉﻠﻮﺩ ﻭﺍﻟﺸﻌﺮ ﻭﺍﻟﻮﺑﺮ ﻭﺍﳊﺮﻳﺮ‪ ،‬ﻭﻣﻦ ﺍﳌﻮﺍﺩ ﺍﻟﻐﺬﺍﺋﻴـﺔ‬ ‫ﺍﻟﻄﺒﻴﻌﻴﺔ ﺍﻟﻨﺸﺎ ﻭﺍﻟﺴﻠﻮﻟﻮﺯ ﻭﺍﻟﱪﻭﺗﲔ‪ ،‬ﻭﲨﻴﻌﻬﺎ ﺗﻜﻮﻥ ﻣﺼﺪﺭﹰﺍ ﳌﺮﻛﺒﺎﺕ ﺑﻮﻟﻴﻤﺮﻳﺔ ﻃﺒﻴﻌﻴﺔ ﺿﺮﻭﺭﻳﺔ ﳊﻴﺎﺗﻨﺎ‬ ‫ﺍﻟﻴﻮﻣﻴﺔ‪.‬‬ ‫‪Synthetic Polymers@HòîÇbäĐ•üaI@ñŠša@paŠàîÛìjÛa@MR‬‬

‫ﻭﻫﺬﻩ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﶈﻀﺮﺓ ﻭﺍﳌﺼﻨﻌﺔ‪ ،‬ﻭﻫﻰ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﻟﱴ ﻋﺮﻑ ﺍﻷﺳﻮﺍﻕ ﺍﻟﻌﺎﳌﻴـﺔ ﺑـﺸﻜﻞ‬ ‫ﻓﻌﺎﻝ ﰱ ﳎﺎﻝ ﻋﺪﻳﺪﺓ‪ .‬ﻭﻣﻨﻬﺎ ﺍﳌﻮﺍﺩ ﺍﻟﺒﻼﺳﺘﻴﻜﻴﺔ ﻭﺍﳌﻄﺎﻁ ﻭﺍﳉﻠﻮﺩ ﺍﻟﺼﻨﺎﻋﻴﺔ ﻭﺃﻗﻤﺸﺔ ﺍﻟﻨﺎﻳﻠﻮﻥ ﻭﺍﻟﺒـﻮﱃ‬ ‫ﺃﺳﺘﺮ ﻭﺑﻌﺾ ﺍﻟﺼﺒﺎﻍ ﻭﺃﻧﻮﺍﻉ ﻣﻦ ﺍﻟﻄﻼﺀ ﺍﻟﻮﺍﻗﻰ ﻭﻏﲑﻫﺎ‪ .‬ﻭﻣﻦ ﻫﺬﺍ ﻳﺘﻀﺢ ﻣـﺪﻯ ﺃﳘﻴـﺔ ﺍﺳـﺘﺨﺪﺍﻡ‬ ‫ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﰱ ﺣﻘﻮﻝ ﺍﻟﻜﻤﻴﺎﺀ ﻣﺼﻬﻮﺭﺓ ﻣﺒﺎﺷﺮﺓ ﺃﻭ ﻏﲑ ﻣﺒﺎﺷﺮﺓ ﻭﻣﺪﻯ ﺗﺄﺛﲑﻫﺎ ﻋﻠﻰ ﺗﻄﻮﺭ ﻭﺍﺯﺩﻫـﺎﺭ‬ ‫ﺍﻟﺘﻨﻤﻴﺔ ﺍﻟﺼﻨﺎﻋﻴﺔ ﰱ ﻫﺬﺍ ﺍ‪‬ﺎﻝ‪ .‬ﻛﻤﺎ ﻇﻬﺮﺕ ﰱ ﺍﻵﻭﻧﺔ ﺍﻷﺧﲑﺓ ﺩﺧﻮﻝ ﺻﻨﺎﻋﺔ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺑﻘﻮﺓ ﰱ ﻋﺎﱂ‬ ‫ﺍﻻﻟﻜﺘﺮﻭﻧﻴﺎﺕ ﺣﱴ ﺩﺧﻠﺖ ﰱ ﺗﺼﻨﻴﻊ ﻣﺼﺎﺩﺭ ﺍﻟﻄﺎﻗﺔ ﻟﻸﺟﻬﺰﺓ ﺍﻻﻟﻜﺘﺮﻭﻧﻴﺔ ﺍﶈﻤﻮﻟﺔ ﻧﻈﺮﹰﺍ ﳊﻈﺔ ﻭﺯ‪‬ـﺎ‪.‬‬ ‫ﻭﺗﻌﺘﱪ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﻻﺻﻄﻨﺎﻋﻴﺔ ﺑﺴﻴﻄﺔ ﻧﺴﺒﻴﹰﺎ ﺇﺫﺍ ﻣﺎ ﻗﻮﺭﻧﺖ ﺑﺎﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﻟﻄﺒﻴﻌﻴـﺔ ﻭﺃﻗـﻞ ﻣﻨـﻬﺎ ﰱ‬ ‫ﺍﻟﺘﻜﻠﻔﺔ‪.‬‬ ‫‪١٤٢‬‬


‫‪@ @paŠàîÛìjÛa@ãì@SMTMW‬‬ ‫ﻣﻦ ﺃﻫﻢ ﺧﻮﺍﺹ ﺍﳌﻤﻴﺰﺓ ﻟﻠﺒﻮﻟﻴﻤﺮﺍﺕ ﻫﻰ‪:‬‬ ‫• ﺍﻟﻮﺯﻥ ﺍﳉﺰﻳﺌﻰ‬ ‫• ﺍﳋﻮﺍﺹ ﺍﻟﻔﻴﺰﻳﺎﺋﻴﺔ‬ ‫‪@ @ó÷íŒ¦a@æ‹ìÛa@MQ‬‬ ‫ﺗﺘﻤﻴﺰ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺑﻮﺯ‪‬ﺎ ﺍﳉﺰﻳﺌﻰ ﺍﳌﺮﺗﻔﻊ ﻷ‪‬ﺎ ﻣﺮﻛﺒﺎﺕ ﻛﻴﻤﻴﺎﺋﻴﺔ ﺃﺳﺎﺳﻬﺎ ﺍﻷﻛـﺴﺠﲔ ﻭﺍﻟﻨـﺘﲑﻭﺟﲔ‬ ‫ﻭﺍﻟﻜﺮﺑﻮﻥ ﻭﻫﻰ ﻋﻨﺎﺻﺮ ﺃﻭﺯﺍ‪‬ﺎ ﺍﳉﺰﻳﺌﻴﺔ ﻋﺎﻟﻴﺔ ﺟﺪﺍﹰ‪ ،‬ﻟﺬﻟﻚ ﻓـﺈﻥ ﻣﺮﻛﺒـﺎﺕ ﺍﳉﺰﻳﺌـﺎﺕ ﺍﻻﻟـﻀﺨﻤﺔ‬ ‫ﻟﻠﺒﻮﻟﻴﻤﺮﺍﺕ ﻻ ﺗﻮﺟﺪ ﺇﻻ ﰱ ﺣﺎﻟﺘﲔ ﻓﻘﻂ ﺳﺎﺋﻠﺔ ﺃﻭ ﺻﻠﺒﺔ ﻷﻥ ﺿﻐﻂ ﺃﲞﺮﺓ ﺍﳌﺮﻛﺒﺎﺕ ﻳـﻨﻘﺺ ﺑﺰﻳـﺎﺩﺓ‬ ‫ﺍﻟﻮﺯﻥ ﺍﳉﺰﻳﺌﻰ ﻭﻗﺪ ﻳﻬﺒﻂ ﺇﱃ ﺍﻟﺼﻔﺮ ﻗﺒﻞ ﺃﻥ ﻳﺼﻞ ﺍﳉﺰﺉ ﺍﻟﻀﺨﻢ ﺇﱃ ﻗﻴﻤﺘﻪ ﺍﳌﻤﻴﺰﺓ‪.‬‬ ‫‪@ @òîöbíŒîÐÛa@ãìä@MR‬‬ ‫ﳝﻜﻦ ﺗﺼﻨﻴﻒ ﻣﺮﻛﺒﺎﺕ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﻣﻦ ﺣﻴﺚ ﺣﺎﻟﺘﻬﺎ ﺍﻟﻔﻴﺰﻳﺎﺋﻴﺔ ﺇﱃ ﺛﻼﺙ ﺣﺎﻻﺕ‪:‬‬ ‫ ‪@ @@ñ‰ìÜjnß‬‬‫ ‪@ @@ñ‰ìÜjnß@Ë‬‬‫ ‘‪@ @@HpaŠàÜjÛaI@ñ‰ìÜjnß@òj‬‬‫ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﳌﺘﺒﻠﻮﺭﺓ‪ :‬ﻫﻰ ﺍﻟﺒﻠﻮﺭﺍﺕ ﺍﳌﻜﻮﻧﺔ ﺗﺮﺍﻛﻴﺐ ﻣﻨﺘﻈﻤﺔ‪ ،‬ﻭﻧﺎﺩﺭﹰﺍ ﻣﺎ ﺗﻜﻮﻥ ﺑﻠﻮﺭﺍﺕ ﻣﻨﻔـﺮﺩﺓ‬ ‫ﺫﺍﺕ ﺃﺷﻜﺎﻝ ﻫﻨﺪﺳﻴﺔ ﺛﺎﺑﺘﺔ‪ ،‬ﻛﻤﺎ ﰱ ﺍﳌﺮﻛﺒﺎﺕ ﺍﻟﻌﻀﻮﻳﺔ ﺍﻟﺒﺴﻴﻄﺔ ﻭﺍﳌﺮﻛﺒﺎﺕ ﺍﻟﻼﻋﻀﻮﻳﺔ‪ .‬ﻭﻋﻤﻮﻣﹰﺎ‬ ‫ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﳌﺘﺒﻠﻮﺭﺓ ﺗﻜﻮﻥ ﻣﺎﺩﺓ ﺻﻠﺒﺔ‪.‬‬ ‫ ﺃﻣﺎ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﻏﲑ ﺍﳌﺘﺒﻠﻮﺭﺓ‪ :‬ﻓﺘﻜﻮﻥ ﻓﻴﻬﺎ ﺳﻼﺳﻞ ﺍﳉﺰﺋﻴﺎﺕ ﺍﻟﺒﻮﻟﻴﻤﺮﻳﺔ ﻣﻨﺘﺸﺮﺓ ﺑـﺸﻜﻞ ﻏـﲑ‬ ‫ﻣﻨﺘﻈﻢ‪ .‬ﻭﺗﻌﺪ ﻫﺬﻩ ﺍﻷﻧﻈﻤﺔ ﺳﻮﺍﺋﻞ ﻣﻦ ﺍﻟﻨﺎﺣﻴﺔ ﺍﻟﻔﻴﺰﻳﺎﺋﻴﺔ ﻭﺗﺴﻤﻰ ﺑﺎﻟﺴﻮﺍﺋﻞ ﺍﳌﺘﺠﻤﺪﺓ ﻭﻛﻤـﺎ ﻫـﻮ‬ ‫ﺍﳊﺎﻝ ﰱ ﺍﻟﺰﺟﺎﺝ ﺍﻻﻋﺘﻴﺎﺩﻱ‪ .‬ﻭﻋﺎﺩﺓ ﺗﻜﻮﻥ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﻏﲑ ﺍﳌﺘﺒﻠﻮﺭﺓ ﺷـﻔﺎﻓﺔ ﻛﺎﻟﺰﺟـﺎﺝ ﻭﺫﺍﺕ‬ ‫ﻣﺮﻭﻧﺔ ﺃﻛﺜﺮ ﻧﺴﺒﻴﺎ ﻣﻦ ﺍﳌﺘﺒﻠﻮﺭﺓ ﻭﻋﻤﻮﻣﹰﺎ ﺗﻜﻮﻥ ﺍﳌﻨﺎﻃﻖ ﺍﳌﺘﺒﻠﻮﺭﺓ ﰱ ﺍﻟﺒﻮﻟﻴﻤﺮ ﻣﻨﺘﻈﻤـﺔ ﺃﻣـﺎ ﺑـﺎﻗﻰ‬ ‫ﺍﻟﺴﻼﺳﻞ ﺍﻟﺒﻮﻟﻴﻤﺮﻳﺔ ﻓﺘﺒﻘﻰ ﻣﻮﺯﻋﺔ ﺑﺸﻜﻞ ﻏﲑ ﻣﻨﺘﻈﻢ ﻭﺗﻜﻮﻥ ﰱ ﺍﳊﺎﻟﺔ ﺍﻟﺰﺟﺎﺟﻴﺔ‪ ،‬ﻭﺍﻟﻨﺴﺒﺔ ﺑـﲔ‬ ‫ﺍﳌﻨﺎﻃﻖ ﺍﳌﻨﺘﻈﻤﺔ ﺍﳌﺘﺒﻠﻮﺭﺓ ﻭﻏﲑ ﺍﳌﻨﺘﻈﻤﺔ ﺗﺪﻋﻰ ﺑﺪﺭﺟﺔ ﺍﻟﺘﺒﻠﻮﺭ‪.‬‬ ‫ﻭﺗﻌﺘﻤﺪ ﺩﺭﺟﺔ ﺍﻟﺘﺒﻠﻮﺭ ﻋﻠﻰ ﻋﺪﺓ ﻋﻮﺍﻣﻞ ﻣﻨﻬﺎ‪:‬‬ ‫ ﻃﺒﻴﻌﻴﺔ ﺍ‪‬ﺎﻣﻴﻊ ﺍﻟﻔﻌﺎﻟﺔ ﺍﳌﺴﺘﺒﺪﻟﺔ ﺍﳌﻮﺟﻮﺩﺓ ﻋﻠﻰ ﺍﻟﺴﻠﺴﻠﺔ ﺍﻟﺒﻮﻟﻴﻤﺮﻳﺔ‬‫ ﺣﺠﻤﻬﺎ ﻭﻣﺪﻯ ﺗﻄﺒﻴﺘﻬﺎ‪.‬‬‫ ﺩﺭﺟﺔ ﺗﻔﺮﻉ ﺍﻟﺴﻼﺳﻞ ﻭﺍﻻﻧﺘﻈﺎﻡ ﺍﻟﻔﺮﺍﻏﻰ ﳍﺎ‪.‬‬‫ ﻭﻛﻠﻤﺎ ﻗﻠﺖ ﺩﺭﺟﺔ ﺍﻟﺘﻔﺮﻉ ﻭﻛﺎﻧﺖ ﺍﻟﺴﻼﺳﻞ ﻣﺘﺎﺟﻨﺴﺔ ﻭﻣﻨﺘﻈﻤﺔ ﻛﻠﻤﺎ ﺯﺍﺩﺕ ﺍﻟﻘﺪﺭﺓ ﻋﻠﻰ ﺍﻟﺘﺒﻠﻮﺭ‬‫ﻭﺍﻟﻌﻜﺲ ﺑﺴﺒﺐ ﺇﺯﺩﻳﺎﺩ ﺍﻟﻘﻮﻯ ﺍﻟﺒﻴﻨﻴﺔ ﻟﻠﺠﺰﺋﻴﺎﺕ‪.‬‬ ‫‪١٤٣‬‬


‫‪@ @paŠàîÛìjÛa@áîÔm@ÖŠ@TMTMW‬‬ ‫ﻣﻦ ﺃﻫﻢ ﻃﺮﻕ ﻟﻠﺘﻘﺴﻴﻢ ﻫﻮ ﺗﻘﺴﻴﻢ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺗﺒﻌﹰﺎ ﻟـ‪:‬‬ ‫* ﻃﺮﻳﻘﺔ ﺍﻟﺘﺼﻨﻴﻊ‬ ‫* ﻃﺮﻳﻘﺔ ﺍﻻﺳﺘﺨﺪﺍﻡ‬ ‫‪@ @Éîä–nÛa@òÔíŠĐÛ@bÔj@paŠàîÛìjÛa@áîÔm‬‬ ‫ﻓﺘﻨﻘﺴﻢ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺗﺒﻌﺎ ﻟﻄﺮﻕ ﺍﻟﺘﺼﻨﻴﻊ ﺇﱃ‪:‬‬ ‫‪(Thermoplastics)@pbØînýiìßŠrÛa@MQ‬‬ ‫ﻭﻫﻰ ﻣﻦ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﻟﺼﻨﺎﻋﻴﺔ ﺍﻟﺼﻠﺒﺔ ﺍﻟﱴ ﺗﻠﲔ ﺑﺈﺭﺗﻔﺎﻉ ﺩﺭﺟﺔ ﺍﳊﺮﺍﺭﺓ ﰒ ﺗﻌﻮﺩ ﻟـﺼﻼﺑﺘﻬﺎ ﺑﺎﻟﺘﱪﻳـﺪ‬ ‫ﺩﻭﻥ ﺣﺪﻭﺙ ﺃﻯ ﺗﻐﲑ ﰱ ﺗﺮﻛﻴﺒﻬﺎ ﺍﻟﻜﻴﻤﻴﺎﺋﻰ‪ ،‬ﻭﳝﻜﻦ ﺇﻋﺎﺩﺓ ﺗﺸﻜﻴﻠﻬﺎ ﻋﺪﺓ ﻣﺮﺍﺕ ﺑﺎﻟﺘﻨﺎﻭﺏ ﺑﺎﻟﺘـﺴﺨﲔ‬ ‫ﻭﺍﻟﺘﱪﻳﺪ‪ ،‬ﻭﻋﻤﻮﻣﹰﺎ ﻳﻄﻠﻖ ﻋﻠﻴﻬﺎ ﺃ‪‬ﺎ ﻗﺴﻢ ﻣﻦ ﺃﻗﺴﺎﻡ ﺍﻟﺒﻼﺳﺘﻚ‪ .‬ﻭﻣﻦ ﺧﻮﺍﺹ ﺍﻟﺜﺮﻣﻮﺑﻼﺳﺘﻴﻚ ﺃﻧﻪ ﳝﻜـﻦ‬ ‫ﺃﻥ ﲡﺮﻯ ﻋﻠﻴﻪ ﺃﻋﻤﺎﻝ ﺍﻟﺘﺸﻐﻴﻞ ﺍﻟﱴ ﲡﺮﻯ ﻋﻠﻰ ﺍﳌﻌﺎﺩﻥ ﻣﺜﻞ ﺍﻟﺜﻘﺐ ﻭﺍﳋﺮﺍﻃﺔ‪ ،‬ﻭﳝﻜﻦ ﳊﺎﻣﺔ ﺑﻮﺍﺳـﻄﺔ‬ ‫ﺍﳊﺮﺍﺭﺓ‪ .‬ﻭﻣﻦ ﺃﻣﺜﻠﺔ ﻫﺬﺍ ﺍﻟﻨﻮﻉ‪:‬‬ ‫‪ -‬ﺍﻟﺒﻮﱃ ﺇﺛﻠﻴﻠﲔ‪.‬‬

‫‪ -‬ﺍﻟﺒﻮﱃ ﺍﺳﺘﺮﻳﻦ‪.‬‬

‫‪ -‬ﺍﻟﺒﻮﱃ ﺃﻣﻴﺪ‪.‬‬

‫‪ -‬ﺍﻟﻨﺎﻳﻠﻮﻥ‪.‬‬

‫‪(Thermosets) pbØîmbnìßŠrÛa@MR‬‬ ‫ﻫﻮ ﺍﻟﻨﻮﻉ ﺍﻟﺬﻯ ﻳﻠﲔ ﰱ ﺍﻟﺒﺪﺍﻳﺔ ﺑﺎﻟﺘﺴﺨﲔ ﻭﻟﻜﻦ ﻳﺘﺼﻠﺐ ‪‬ﺎﺋﻴﺎ ﺑﺎﻟﺘﱪﻳﺪ ﻷﻭﻝ ﻣـﺮﺓ‪ ،‬ﺇﺫ ﺃﻥ ﺍﻟﺘـﺴﺨﲔ‬ ‫ﻼ ﻛﻴﻤﻴﺎﺋﻴﹰﺎ ﻳﺮﺑﻂ ﺍﻟﺴﻼﺳﻞ ﺍﳌﻜﻮﻧﺔ ﳉﺰﻳﺌﺎﺗﻪ ﺗﺒﺎﺩﻟﻴﹰﺎ ﺑﺮﻭﺍﺑﻂ ﲤﺘﻊ ﺇﻧﺰﻻﻗﻬﺎ ﻭﻻ ﺗﻨﺴﺎﺏ‬ ‫ﺍﻷﻭﻝ ﳛﺪﺙ ﺗﻔﺎﻋ ﹰ‬ ‫ﻣﻊ ﺍﳊﺮﺍﺭﺓ ﺃﻭ ﺍﻟﻀﻐﻂ‪ ،‬ﻛﻤﺎ ﺃﻥ ﺍﳌﺬﻳﺒﺎﺕ ﻻ ﺗﺘﻤﻜﻦ ﻣﻦ ﺗﻌﺮﻳﻔﻬﺎ‪ ،‬ﻭﻟﺬﻟﻚ ﻓﺈﻥ ﺍﻟﺜﺮﻣﻮﺳﺘﺎﺗﻴﻜﺎﺕ ﺗﺼﻠﺢ‬ ‫ﻟﻼﺳﺘﻌﻤﺎﻝ ﻋﻨﺪ ﺩﺭﺟﺎﺕ ﺍﳊﺮﺍﺭﺓ ﺍﻟﻌﺎﻟﻴﺔ ﻧﺴﺒﻴﹰﺎ‪ .‬ﻭﳝﺘﺎﺯ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﲞﻮﺍﺻﺔ ﺍﻟﻜﻬﺮﺑﺎﺋﻴﺔ ﺍﳉﻴـﺪﺓ ﻭﻗﻮﺗـﻪ‬ ‫ﻭﻣﻘﺎﻭﻣﺘﻪ ﺍﳌﺎﻟﻴﺔ ﻟﻠﺰﺣﻒ ﻭﺍﻟﻜﻴﻤﺎﻭﻳﺎﺕ‪.‬‬ ‫ﻭﻣﻦ ﺃﻣﺜﻠﺔ ﻫﺬﺍ ﺍﻟﻨﻮﻉ‪:‬‬ ‫‪ -‬ﺍﻟﺒﻜﺎﻟﻴﺖ‪.‬‬

‫‪ -‬ﺍﻟﺒﻮﱃ ﺍﺳﺘﺮ‪.‬‬

‫‪ -‬ﺍﻷﻳﺒﻮﺳﻜﻰ‪.‬‬

‫‪ -‬ﺍﻟﺴﻴﻠﻴﻜﻮﻥ‪.‬‬

‫ﻭﻗﺪ ﺗﺴﺘﺨﺪﻡ ﺍﻟﺜﺮﻣﻮﺳﺘﺎﺗﻴﻜﺎﺕ ﰱ ﺻﻨﺎﻋﺔ ﺑﻌﺾ ﺍﳌﻮﺍﺩ ﺍﻟﻼﺻﻘﺔ ﻭﺍﶈﺴﻨﺔ ﺑﺘﻘﻮﻳﺘﻬﺎ ﺑﺒﻌﺾ ﺍﳌﻮﺍﺩ ﺍﳌﺎﻟﺌـﺔ‬ ‫ﻣﺜﻞ ﻛﺮﺑﻮﻧﺎﺕ ﺍﻟﻜﺎﻟﺴﻴﻮﻡ ﻭﺍﳌﻴﻜﺎ ﻭﺍﻟﺴﻴﻠﻴﻜﺎ ﻭﺍﻷﺳﺒﺴﺘﻮﺱ ﻭﺫﻟﻚ ﻟﻠﺤﺼﻮﻝ ﻋﻠﻰ ﻣﺜﻞ ﺍﳌﻮﺍﺩ ﺍﻵﺗﻴﺔ‪:‬‬ ‫‪ -‬ﺍﻟﺒﻮﱃ ﻳﻮﺭﻳﺜﺎﻥ‪.‬‬

‫‪ -‬ﺍﻟﻴﻮﺭﻳﺎ‪.‬‬

‫‪ -‬ﻟﺪﺍﺋﻦ ﺍﳌﻴﻼﻓﲔ‪.‬‬

‫ ﻟﺪﺍﺋﻦ ﺍﻟﻔﻴﻨﻮﻝ ﻭﺍﻷﻳﺒﻮﻛﺴﻰ‪.‬‬‫‪١٤٤‬‬


‫‪(Plastics) pbã†Ü½a@MS‬‬ ‫ﻭﻫﻰ ﻣﻦ ﺍﳌﻮﺍﺩ ﺍﻟﻌﻀﻮﻳﺔ ﺍﻟﺼﻐﲑﺓ ﻭﺗﺴﺘﺨﺪﻡ ﻛﻤﻠﺪﻧﺎﺕ ﻟﻠﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﻟﺼﻠﺒﺔ ﻣﺜﻞ ﺍﳌـﻮﺍﺩ ﺍﻟﺒﻼﺳـﺘﻴﻜﻴﺔ‬ ‫ﻟﺘﻌﻄﻴﻬﺎ ﻟﻴﻮﻧﺔ ﻭﻣﻦ ﺃﻫﻢ ﺍﳌﻠﺪﻧﺎﺕ ﺛﻨﺎﺋﻰ ﺍﻟﻜﻴﻞ ﻓﻴﺜﺎﻻﺕ‪.‬‬ ‫‪(Ellastomers) HòãŠ½a@paŠàîÛìjÛa@I@paßìnÛ⁄a@MT‬‬ ‫ﻭﻫﻰ ﻣﻮﺍﺩ ﻫﻴﺪﺭﻭﻛﺮﺑﻮﻧﻴﺔ ﻏﲑ ﻣﺸﺒﻌﺔ ﺫﺍﺕ ﺃﻭﺯﺍﻥ ﺟﺰﺋﻴﺔ ﻋﺎﻟﻴﺔ‪ ،‬ﻭﺗﺘﻤﻴﺰ ﺗﻠﻚ ﺍﳌﻮﺍﺩ ﺑﺈﻥ ﳍـﺎ ﺍﻟﻘـﺪﺭﺓ‬ ‫ﺍﻟﻌﺎﻟﻴﺔ ﻋﻠﻰ ﺍﻻﺳﺘﻄﺎﻟﺔ ﻓﻘﺪ ﺗﺘﺤﻤﻞ ﺯﻳﺎﺩﺓ ﰱ ﺍﻟﻄﻮﻝ ﻣـﻦ ‪ % ٥٠٠ : ١٠٠‬ﰒ ﺗﻌـﻮﺩ ﺇﱃ ﺷـﻜﻠﻬﺎ‬ ‫ﺍﻷﺻﻠﻰ ﺑﻌﺪ ﺯﻭﺍﻝ ﺍﳊﻤﻞ ﺍﳌﺆﺛﺮ‪ ،‬ﻭﻣﻦ ﺃﻣﺜﻠﺔ ﺗﻠﻚ ﺍﻟﻨﻮﻉ ﺍﳌﻄﺎﻁ‪.‬‬ ‫‪(Fibers)@@òîÇbä–Ûa@ÒbîÛþa@MU‬‬ ‫ﻭﻫﻰ ﻣﻦ ﺃﻫﻢ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﳌﺴﺘﺨﺪﻣﺔ ﰱ ﺍﻟﺼﻨﺎﻋﺔ‪ ،‬ﻭﲤﺘﺎﺯ ﲟﻘﺎﻭﻣﺘﻬﺎ ﺍﻟﻌﺎﻟﻴﺔ ﻟﻠﺘـﺸﻮﺓ ﻭﺍﻟـﺸﺪ ﻭﻟﻜـﻦ‬ ‫ﺗﺘﺤﻤﻞ ﺍﺳﺘﻄﺎﻟﺔ ﺻﻐﲑﺓ ﻗﺪ ﺗﺼﻞ ﺇﱃ ﺣﻮﺍﱃ )‪ ،(%٥٠ – ١٠‬ﻭﲤﺘﺎﺯ ﺃﻳـﻀﺎ ﺑـﻀﻌﻒ ﺍﻣﺘـﺼﺎﺻﻬﺎ‬ ‫ﻟﻠﺮﻃﻮﺑﺔ‪ ،‬ﻛﻤﺎ ﺃﻥ ﳍﺎ ﺩﺭﺟﺔ ﺗﺒﻠﻮﺭ ﻋﺎﻟﻴﺔ‪ ،‬ﻭﻣﻦ ﺃﻣﺜﻠﺔ ﻫﺬﻩ ﺍﻷﻟﻴﺎﻑ‪:‬‬ ‫ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺃﺳﺘﺮ‪.‬‬‫ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺃﻣﻴﺪ‪.‬‬‫ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺗﺒﻠﲔ‪.‬‬‫‪@ @âa†‚nüa@òÔíŠĐÛ@bÔj@paŠàîÛìjÛa@áîÔm‬‬ ‫‪Ellastomers@paßìnÛ⁄a@MQ‬‬

‫ﻭﻫﻰ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﳌﺮﻧﺔ ﺍﳌﻄﺎﻃﻴﺔ ﻣﺜﻞ ﺍﳌﻄﺎﻁ ﻭﻏﲑﺓ‬ ‫‪ÙînýjÛa@MR‬‬

‫‪Plastics‬‬

‫ﻭﻫﻰ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﻟﺼﻠﺒﺔ ﺍﻟﱴ ﺗﺘﺪﺭﺝ ﻣﻦ ﺑﻮﻟﻴﻤﺮﺍﺕ ﻟﺪﻧﺔ ﺇﱃ ﺷﺪﻳﺪﺓ ﺍﻟﺼﻼﺑﺔ ﻣﺜﻞ ﺍﻟﺒﻮﻳﺎﺕ ﻭﺍﻟﺒـﻮﱃ‬ ‫ﺇﻳﺜﻠﲔ ﻭﻏﲑﻫﺎ‪.‬‬ ‫‪Fibers òîÇbä–Ûa@ÒbîÛþa@MS‬‬

‫ﻭﻫﻰ ﺑﻮﻟﻴﻤﺮﺍﺕ ﺗﺴﺘﺨﺪﻡ ﻟﺼﻨﺎﻋﺔ ﺍﻷﻧﺴﺠﺔ ﺍﳌﺼﻨﻌﺔ ﻣﺜﻞ ﺍﻟﺒﻮﱃ ﺃﻣﻴﺪﺍﺕ ﻭﻏﲑﻫﺎ‪.‬‬ ‫‪١٤٥‬‬


‫‪@ @paŠàîÛìjÛa@pübàÈna@UMTMW‬‬ ‫ﻣﻦ ﺃﻫﻢ ﺍﺳﺘﻌﻤﺎﻻﺕ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﻭﺑﺎﻷﺧﺺ ﰱ ﳎﺎﻝ ﺍﳌﻨﺸﺂﺕ ﺍﳋﺮﺳﺎﻧﻴﺔ ﻫﻰ‪:‬‬ ‫‪ -١‬ﺗﺴﺘﺨﺪﻡ ﺍﳌﻮﺍﺩ ﺍﻟﺴﺎﺋﻠﺔ ﻣﻦ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﻛﻺﺿﺎﻓﺔ ﻟﻠﺨﺮﺳﺎﻧﺔ ﻟﻠﺤﺼﻮﻝ ﻋﻠﻰ ﺧﻮﺍﺹ ﻣﻌﻴﻨﺔ ﻣﺜـﻞ‬ ‫ﺗﻠﻴﻠﻴﺔ ﺗﺸﻐﻴﻞ ﻋﺎﻟﻴﺔ ﻭﻣﻘﺎﻭﻣﺔ ﺍﻟﺘﺸﻮﻩ ﻭﺍﻟﺼﺪﻡ ﻭﻣﻘﺎﻭﻣﺔ ﺿﻐﻂ ﻋﺎﻟﻴﺔ ‪ ،‬ﻣﻘﺎﻭﻣﺔ ﺷﺪ ﻭﺇﳓﻨﺎﺀ ﻣﺘﻤﻴـﺰﺓ‬ ‫ﻭﻋﺎﻟﻴﺔ‪.‬‬ ‫‪ -٢‬ﺗﺴﺘﺨﺪﻡ ﺑﻌﺾ ﻣﻦ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﻟﺴﺎﺋﻠﺔ ﻛﻮﺳﻂ ﺳﺎﺋﻞ ﻹﻧﺘﺎﺝ ﺧﺮﺳﺎﻧﺔ ﺃﻭ ﻣﻮﻧﺔ ﺭﺍﺗﻨﺠﻴﺔ ﺑﺪ ﹰﻻ ﻣـﻦ‬ ‫ﺍﻷﲰﻨﺖ‪.‬‬ ‫‪ -٣‬ﺗﺴﺘﺨﺪﻡ ﰱ ﺩﻫﺎﻧﺎﺕ ﺍﻷﺳﻄﺢ ﺍﳋﺮﺳﺎﻧﺔ ﺍﳋﺎﺭﺟﻴﺔ ﻟﻐﻠﻖ ﺍﳌﺴﺎﻡ ﻭﻣﻨﻊ ﺗﺴﺮﺏ ﺍﻟﺴﻮﺍﺋﻞ ﺇﻟﻴﻬﺎ‪.‬‬ ‫‪ -٤‬ﺗﺴﺘﺨﺪﻡ ﻣﻨﻬﺎ ﺑﻌﺾ ﺍﳌﻮﺍﺩ ﺍﻷﻳﺒﻮﻛﺴﻴﺔ ﻟﻠﺼﻖ ﺍﳋﺮﺳﺎﻧﺔ ﺍﳊﺪﻳﺜﺔ ﻣﻊ ﺧﺮﺳﺎﻧﺔ ﻗﺪﳝﺔ‪ ،‬ﻛﻤﺎ ﻳﺴﺘﺨﺪﻡ‬ ‫ﰱ ﻟﺼﻖ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﻣﻊ ﺧﺮﺳﺎﻧﺔ ﻣﺼﺒﻮﺑﺔ ﻭﻛﺬﻟﻚ ﰱ ﻟﺼﻖ ﺍﻟﻮﺣﺪﺍﺕ ﺳﺎﺑﻘﺔ ﺍﻟﺼﺐ‪.‬‬ ‫‪ -٥‬ﺗﺴﺘﺨﺪﻡ ﰱ ﺻﻨﺎﻋﺔ ﺍﳋﺮﺳﺎﻧﺔ ﺍﻟﺒﻮﻟﻴﻤﺮﻳﺔ ﺍﻷﲰﻨﺘﻴﺔ ﻭﺍﳋﺮﺳﺎﻧﺔ ﺍﳌﻐﻠﻔـﺔ ﺑـﺎﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﻭﺍﳋﺮﺳـﺎﻧﺔ‬ ‫ﺍﻟﺒﻮﻟﻴﻤﺮﻳﺔ ﺃﻭ ﺍﻟﺒﻼﺳﺘﻴﻜﻴﺔ ﺃﻭ ﺍﻟﺮﺍﺗﻨﺠﻴﺔ‪.‬‬ ‫‪ -٦‬ﺗﺴﺘﺨﺪﻡ ﺭﻗﺎﺋﻖ ﺍﳌﻮﺍﺩ ﺍﻟﺒﻼﺳﺘﻴﻜﻴﺔ ﻣﻦ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﰱ ﻓﻮﺍﺻـﻞ ﺍﻟـﺼﺐ ﳌﻨـﻊ ﺗـﺴﺮﺏ ﺍﳌﻴـﺎﻩ‬ ‫ﻭﺍﻟﺴﻮﺍﺋﻞ‪.‬‬ ‫‪ -٧‬ﺗﺴﺘﺨﺪﻡ ﺍﻷﻟﻮﺍﺡ ﺍﻟﺒﻼﺳﺘﻴﻜﻴﺔ ﰱ ﻓﺮﻡ ﺍﻷﻋﻤﺎﻝ ﺍﳋﺮﺳﺎﻧﻴﺔ‪.‬‬

‫‪١٤٦‬‬


‫‪Fibers :( -5-7‬‬

‫ﺗﻨﺘﺞ ﺍﻷﻟﻴﺎﻑ ﻣﻦ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﻭﻫﻰ ﻣﻦ ﺃﻫﻢ ﺗﻘﺴﻴﻤﺘﻬﺎ ﰱ ﺍﻟﺘﺼﻨﻴﻊ ﻭﺍﻻﺳـﺘﺨﺪﺍﻡ‪ ،‬ﻭﺗﻌﺘـﱪ ﺍﻷﻟﻴـﺎﻑ‬ ‫ﲟﺨﺘﻠﻒ ﺃﻧﻮﺍﻋﻬﺎ ﺷﺎﺋﻌﺔ ﺍﻻﺳﺘﺨﺪﺍﻡ ﺧﻼﻝ ﺍﻟﺴﻨﻮﺍﺕ ﺍﻷﺧﲑﺓ ﳌﺎ ﲢﻘﻘﺔ ﻫﺬﻩ ﺍﻷﻟﻴﺎﻑ ﻣﻦ ﲢﺴﲔ ﺧﻮﺍﺹ‬ ‫ﻣﺘﻌﺪﺩﺓ ﰱ ﺍﻟﻜﺜﲑ ﻣﻦ ﺍ‪‬ﺎﻻﺕ ﺍﻟﺼﻨﺎﻋﻴﺔ ﻭﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻭﺍﻻﻧﺸﺎﺋﻴﺔ ﻭﺍﳌﻌﻤﺎﺭﻳﺔ ﺑﺸﻜﻞ ﻣﻠﺤﻮﻅ‪.‬‬ ‫ﻭﻣﻦ ﺃﻫﻢ ﺃﻧﻮﺍﻉ ﺍﻷﻟﻴﺎﻑ ﺍﳌﺴﺘﺨﺪﻣﺔ‪:‬‬ ‫‪-‬‬

‫‪@ @@òîubuŒÛa@ÒbîÛþa‬‬

‫‪-‬‬

‫‪òîãìiŠØÛa@ÒbîÛþa‬‬

‫‪-‬‬

‫‪@´ÜiëŠi@µìjÛa@ÒbîÛc‬‬

‫‪-‬‬

‫‪@†îß‰þa@ÒbîÛc‬‬

‫ﻭﺳﻮﻑ ﻳﺘﻢ ﺗﻮﺿﺢ ﻛﻞ ﻧﻮﻉ ﻋﻠﻰ ﺣﺪﻩ‬ ‫‪xbuŒÛa@bèbc@ónÛa@òîÇbä–Ûa@ÒbîÛþa@xbnã@óç@òîubuŒÛa@ÒbîÛþa@òîubuŒÛa@ÒbîÛþa@Q@MU@MW‬‬ ‫ﻭﻟﻸﻟﻴﺎﻑ ﺍﻟﺰﺟﺎﺟﻴﺔ ﺃﳘﻴﺔ ﻛﱪﻯ ﰱ ﻛﺜﲑ ﻣﻦ ﺍ‪‬ﺎﻻﺕ ﺍﳌﺨﺘﻠﻔﺔ ﻣﻦ ﺃﻫـﻢ ﺃﺳـﺘﺨﺪﺍﻣﺘﻬﺎ ﰱ ﺍﻷﻋﻤـﺎﻝ‬ ‫ﺍﻹﻧﺸﺎﺋﻴﺔ ﻭﺍﳌﻌﻤﺎﺭﻳﺔ ﻫﻰ ﺇﻧﺘﺎﺝ ﺧﺮﺳﺎﻧﺔ ﻣﺴﻠﺤﺔ ﺑﺎﻷﻟﻴﺎﻑ ﺍﻟﺰﺟﺎﺟﻴﺔ ﳍﺎ ﺃﻏﺮﺍﺽ ﻣﻌﻤﺎﺭﻳﺔ ﳐﺘﻠﻔﺔ‪ ،‬ﻭﺫﻟﻚ‬ ‫ﰱ ﺇﻃﺎﺭ ﺗﻄﻮﻳﺮ ﺻﻨﺎﻋﺔ ﺍﳋﺮﺳﺎﻧﺔ ﺣﻴﺚ ﺃﻧﻪ ﰎ ﺇﻧﺘﺎﺝ ﺧﺮﺳﺎﻧﺔ ﻣﺴﻠﺤﺔ ﺑﺎﻷﻟﻴﺎﻑ ﺍﻟﺰﺟﺎﺟﻴـﺔ ﰲ ﺍﻟﻘـﺮﻥ‬ ‫ﺍﻟﻌﺸﺮﻳﻦ ﻟﺘﻜﻮﻥ ﺍﻟﺒﺪﻳﻞ ﻋﻦ ﻣﻮﺍﺩ ﺍﻹﻛﺴﺎﺀ ﺍﻟﻜﻼﺳﻴﻜﻴﺔ ﻭﺍﻟﻄﺒﻴﻌﻴﺔ ﻛﺎﳊﺠﺮ ﻭﺍﻟﺮﺧﺎﻡ ﻭﻏﲑﻩ ﻭﻟﻴـﺴﺎﻫﻢ‬ ‫ﺑﺸﻜﻞ ﻋﺎﻡ ﰲ ﺍﻹﻧﺸﺎﺀ ﺍﻟﻌﺼﺮﻱ ﺍﻗﺘﺼﺎﺩﻳﺎ ﻭﺗﻘﻨﻴﺎ ﻭﲨﺎﻟﻴﺎ ﰲ ﲨﻴﻊ ﺃﳓﺎﺀ ﺍﻟﻌﺎﱂ ﻣﻨﺬ ﺃﻛﺜﺮ ﻣﻦ ‪ ٣٠‬ﻋﺎﻣـﺎ‬ ‫ﻭﻫﻮ ﰲ ﺗﻄﻮﺭ ﺩﺍﺋﻢ‪ .‬ﻭﺍﳋﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ ﺑﺎﻷﻟﻴﺎﻑ ﺍﻟﺰﺟﺎﺟﻴﺔ ﻫﻰ ﻋﺒﺎﺭﺓ ﻋﻦ ﳎﻤﻮﻋـﺔ ﻣﺘﻜﺎﻣﻠـﺔ ﻣـﻦ‬ ‫ﺍﳌﺮﻛﺒﺎﺕ ﺍﳌﻌﺘﻤﺪﺓ ﻋﻠﻰ ﺍﻷﲰﻨﺖ ﻋﺎﱄ ﺍﻷﺩﺍﺀ ﺍﳌﺴﻠﺢ ﺑﺎﻷﻟﻴﺎﻑ ﺍﻟﺰﺟﺎﺟﻴﺔ ﺫﺍﺕ ﺍﻟﻘﺪﺭﺓ ﺍﳋﺎﺻﺔ ﳌﻘﺎﻭﻣـﺔ‬ ‫ﺍﻟﻘﻠﻮﻳﺎﺕ ﳑﺎ ﳚﻌﻠﻪ ﻗﺎﺑﻼ ﻟﻠﺘﻄﻮﻳﻊ ﻟﻴﻨﺎﺳﺐ ﳎﺎﻻ ﻭﺍﺳﻌﺎ ﻣﻦ ﺍﻟﺘﻄﺒﻴﻘﺎﺕ‪ .‬ﻭﻣﻦ ¾‪@òzÜ;½a@òãb;Šä@paŒ;î‬‬

‫‪:òîubuŒÛa@ÒbîÛþbi‬‬ ‫‪ -١‬ﺇ‪‬ﺎ ﺇﺣﺪﻯ ﻣﻮﺍﺩ ﺍﻟﺒﻨﺎﺀ ﺍﻷﻛﺜﺮ ﻃﻮﺍﻋﻴﺔ ﺍﳌﺘﻮﻓﺮﺓ ﻟﻠﻤﻬﻨﺪﺳﲔ ﻭﺍﳌﻌﻤﺎﺭﻳﲔ‪.‬‬ ‫‪ -٢‬ﻋﻤﻠﻴﺔ ﻹﻋﺎﺩﺓ ﺗﺄﻫﻴﻞ ﺍﳌﻨﺸﺂﺕ ﻭﺍﻟﺘﺮﻣﻴﻢ ﻭﺫﺍﺕ ﺩﺭﺟﺔ ﲨﺎﻝ ﻋﺎﻟﻴﺔ ﻭ ﺻﺪﻳﻘﺔ ﻟﻠﺒﻴﺌﺔ‪.‬‬ ‫‪ -٣‬ﲣﻔﻒ ﺍﻷﻭﺯﺍﻥ ﻋﻠﻰ ﺍﻷﺑﻨﻴﺔ ﺑﻌﻮﺍﻣﻞ ﺃﻣﺎﻥ ﻛﺒﲑﺓ ﻟﻠﻬﻴﺎﻛﻞ ﺍﻟﻀﺨﻤﺔ ﻭﺍﻷﺳﺎﺳﺎﺕ‪.‬‬ ‫‪ -٤‬ﳝﻜﻦ ﺗﻠﻮﻳﻨﻬﺎ ﺑﺎﻟﺼﺒﻐﺎﺕ ﻭ ﺍﻟﺪﻫﺎﻧﺎﺕ ﻛﻤﺎ ﺗﻌﺎﰿ ﺳﻄﻮﺡ ﺍﻟﻄﻴﻨﺔ ﺍﻹﲰﻨﺘﻴﺔ‪.‬‬ ‫‪١٤٧‬‬


‫‪ -٥‬ﲢﻞ ﳏﻞ ﻭﺣﺪﺍﺕ ﺍﳋﺮﺳﺎﻧﺔ ﺳﺎﺑﻘﺔ ﺍﻟﺘﺠﻬﻴﺰ ﻏﲑ ﺍﻹﻧﺸﺎﺋﻴﺔ ﻋﻨﺪﻣﺎ ﺗﻜﻮﻥ ﻫﻨﺎﻙ ﻣﺸﻜﻠﺔ ﰲ ﺍﻟﻮﺯﻥ ﻭ‬ ‫ﺍﻟﺸﻜﻞ‪.‬‬ ‫‪ -٦‬ﻭﳝﻜﻦ ﺗﺸﻜﻴﻞ ﻣﻨﺘﺠﺎﺕ ﺍﳋﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ ﺑﺎﻷﻟﻴﺎﻑ ﺍﻟﺰﺟﺎﺟﻴﺔ ﲟﻘﺎﻃﻊ ﺭﻗﻴﻘﺔ ﺑﺴﻤﺎﻛﺔ‪٦‬ـ‪١٢‬ﻣﻢ‬ ‫ﻟﻴﻜﻮﻥ ﻭﺯ‪‬ﺎ ﺍﻗﻞ ﺑﻜﺜﲑ ﻣﻦ ﻭﺯﻥ ﻣﻨﺘﺠﺎﺕ ﺍﳋﺮﺳﺎﻧﺔ ﺳﺎﺑﻘﺔ ﺍﻟﺘﺠﻬﻴﺰ ﺍﻟﺘﻘﻠﻴﺪﻳﺔ ﺍﳌﻤﺎﺛﻠﺔ ﺑﺎﳊﺠﻢ‪.‬‬ ‫‪ -٧‬ﺍﳋﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ ﺑﺎﻷﻟﻴﺎﻑ ﺍﻟﺰﺟﺎﺟﻴﺔ ﺳﻬﻠﺔ ﺍﻟﺘﺼﻨﻴﻊ ﻭﺍﻟﻘﻮﻟﺒﺔ ﻹﻧﺘـﺎﺝ ﺍﻷﺷـﻜﺎﻝ ﻭﺍﻟﺘﻔﺎﺻـﻴﻞ‬ ‫ﺍﻟﺪﻗﻴﻘﺔ ﻭﻳﻌﻄﻲ ﺍﳌﻠﻤﺲ ﺍﳌﻄﻠﻮﺏ ﻟﻠﺴﻄﻮﺡ ﺍﻟﻨﻬﺎﺋﻴﺔ ﺑﺄﻓﻀﻞ ﻧﻮﻋﻴﺔ‪.‬‬ ‫‪ -٨‬ﺗﺘﺴﻢ ﺍﳋﺮﺳﺎﻧﺔ ﺍﳌﺴﻠﺤﺔ ﺑﺎﻷﻟﻴﺎﻑ ﺍﻟﺰﺟﺎﺟﻴﺔ ﲟﻘﺎﻭﻣﺘﻬﺎ ﻟﻠﺘﺂﻛﻞ ﻭﻟﻠﻈﺮﻭﻑ ﺍﳉﻮﻳﺔ ﺍﳋﺎﺭﺟﻴـﺔ ﻣـﻦ‬ ‫ﺣﺮﺍﺭﺓ ﻭﺭﻃﻮﺑﺔ ﻭﲞﺎﺻﺔ ﻟﻸﺟﻮﺍﺀ ﺍﻟﺒﺤﺮﻳﺔ‪.‬‬ ‫‪ -٩‬ﻋﺎﺯﻟﺔ ﻟﻠﺤﺮﺍﺭﺓ ﻭﺍﻟﺼﻮﺕ ﻭﺗﺘﺴﻢ ﲟﻘﺎﻭﻣﺔ ﻋﺎﻟﻴﺔ ﻟﻠﺤﺮﻳﻖ ﻭﻧﻔﺎﺫ ﺍﳌﺎﺀ‪٠‬‬ ‫‪ -١٠‬ﳍﺎ ﺩﺭﺟﺔ ﻣﻨﺎﺳﺒﺔ ﻣﻦ ﺍﻟﺼﻼﺑﺔ ﻭﺍﳌﻘﺎﻭﻣﺔ ﻟﻠﻜﺴﺮ ﻭﺍﻟﻀﻐﻂ‪٠‬‬ ‫‪@ @ZòîubuŒÛa@ÒbîÛþbi@òzÜ½a@òãbŠä@pbßa†‚na‬‬ ‫@@‬ ‫ﻭﺗﺴﺘﻌﻤﻞ ﻫﺬﻩ ﺍﻟﺘﻘﻨﻴﺔ ﰲ ﺃﻟﻮﺍﺡ ﻟﻜﺴﻮﺓ ﺍﻟﻮﺍﺟﻬﺎﺕ ﺍﳋﺎﺭﺟﻴﺔ ﻭﺍﻷﻋﻤﺪﺓ ﻭﺍﻟﺘﻴﺠﺎﻥ ﻭﻣﻈﻼﺕ ﴰﺲ ﺃﻓﻘﻴﺔ‬ ‫ﻭﻋﻤﻮﺩﻳﺔ ﻛﻤﺎ ﺗﺴﺘﺨﺪﻡ ﻛﻮﺭﻧﻴﺸﺎﺕ ﻭﺃﺳﺎﻭﺭ ﻭﺩﺭﺍﺑﺰﻳﻨﺎﺕ ﻭﺃﺳﻘﻒ ﻣﺴﺘﻌﺎﺭﺓ ﻭﻗﺒﺎﺏ ﺩﺍﺧﻠﻴﺔ ﻭﺧﺎﺭﺟﻴﺔ‬ ‫ﻭﺃﻗﻨﻴﺔ ﻟﻠﺮﻱ ﻭﺍﻟﺼﺮﻑ ﻭﺃﻳﻀﺎ ﻳﺘﻢ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﻛﻘﻮﺍﻟﺐ ﺩﺍﺋﻤﺔ ﻟﺼﺐ ﺍﻷﲰﻨﺖ )ﺿﺎﺋﻌﺔ( ﻭﺗﺼﻨﻊ ﻣﻨـﻬﺎ‬ ‫ﺃﻧﺎﺑﻴﺐ ﻣﻘﻮﺍﺓ ﺑﺪﻭﻥ ﺍﺳﺘﻌﻤﺎﻝ ﺍﻟﻔﻮﻻﺫ‪.‬‬ ‫‪@ @@òîãìiŠØÛa@ÒbîÛþa@R@MU@MW‬‬ ‫@@‬ ‫ﺃﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻥ ﻋﺒﺎﺭﺓ ﻋﻦ ﺃﻟﻴﺎﻑ ﺻﻨﺎﻋﻴﺔ ﺫﺍﺕ ﺷﻜﻞ ﻟﻴﻔﻰ ﻣﻜﻮﻧﺔ ﻣﻦ ﺑﻠﻮﺭﺍﺕ ﺍﻟﻜﺮﺑـﻮﻥ ﺍﻟﺪﻗﻴﻘـﺔ‬ ‫ﺍﳌﺘﻜﻮﻧﺔ ﻧﺘﻴﺠﺔ ﻣﻦ ﺗﻠﻴﻴﻒ ﺭﺍﺗﻨﺞ ﺍﻻﻛﺮﻳﻠﻴﻚ ﺍﳌﺘﻜﻮﻧﺔ ﻣﻦ ﻣﻌﺎﳉﺔ ﻧﻮﺍﺗﺞ ﺗﻘﻄـﲑ ﺍﻟـﻨﻔﻂ ﻭﺍﻟﻔﺤـﻢ ﰱ‬ ‫ﺩﺭﺟﺎﺕ ﺣﺮﺍﺭﺓ ﻣﻌﻴﻨﺔ ‪.‬ﻭﺃﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻥ ﻣﻜﻮﻧﺔ ﻣﻦ ﻣﻮﺍﺩ ﻣﺘﺒﺎﻳﻨﺔ ﻭﻋﻨﺪ ﺻﻨﺎﻋﺘﻬﺎ ﺑﻨﺤـﺮﺹ ﻋﻠـﻰ ﺃﻥ‬ ‫ﺗﻜﻮﻥ ﻫﺬﺓ ﺍﻷﻟﻴﺎﻑ ﻗﻮﻳﺔ ﺟﺪﺍ ً ﻭﺧﻔﻴﻔﺔ ﺟﺪﹰﺍ ‪.‬ﻭﺍﻷﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻧﻴﺔ ﻣﻮﺿﺤﺔ ﺑﺸﻜﻞ )‪.(١-٧‬‬

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‫@@@@@@@@@@@@@‘‪@ @@@@@@@@N@òÐÜn«@jØm@pbu‰†i@æìiŠØÛa@ÒbîÛc@óÏ@ÉĐÔß@@HQMWI@ÝØ‬‬

‫‪ ١-٢-٥-٧‬ﺃﻧﻮﺍﻉ ﺍﻷﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻧﻴﺔ‬ ‫ﻳﺘﻢ ﺗﻘﺴﻴﻢ ﺍﻷﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻧﻴﺔ ﻃﺒﻘﺎ ﻟﻶﰐ‪:‬‬ ‫ﺃ ‪ -‬ﻃﺒﻘﺎ ً ﻷﺳﺎﺱ ﺗﺼﻨﻴﻌﻬﺎ‪:‬‬ ‫‪ -١‬ﺃﻟﻴﺎﻑ ﺫﺍﺕ ﺃﺳﺎﺱ ﻣﺘﻌﺪﺩ ﺍﻻﻛﺮﻳﻠﻮﻧﺘﺮﻳﻞ‪٠‬‬ ‫‪ -٢‬ﺃﻟﻴﺎﻑ ﺫﺍﺕ ﺃﺳﺎﺱ ﺑﻴﺘﻮﻣﻴﲎ‪٠‬‬ ‫‪ -٣‬ﺃﻟﻴﺎﻑ ﺫﺍﺕ ﺃﺳﺎﺱ ﻣﻦ ﺍﳊﺮﻳﺮ ﺍﻟﺼﻨﺎﻋﻰ‪٠‬‬ ‫ﺏ – ﻃﺒﻘﹰﺎ ﻟﻼﺧﺘﻼﻑ ﰱ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﳋﺎﺭﺟﻴﺔ‪:‬‬ ‫ﻣﺜﻞ ﻋﺮﺽ ﺍﻷﻟﻴﺎﻑ ﻭﺍﺭﺗﺒﺎﻁ ﺍﻟﺸﻌﲑﺍﺕ ﺑﻌﻀﻬﺎ ﺑﺒﻌﺾ ﻭﻛﺜﺎﻓﺔ ﺍﻷﻟﻴﺎﻑ ﻭﻣﻦ ﻫﺬﺓ ﺍﻷﻧﻮﺍﻉ ﺍﻷﻟﻴﺎﻑ‬ ‫ﰱ ﺇﲡﺎﺓ ﻭﺍﺣﺪ ﺃﻭ ﰱ ﺇﲡﺎﻫﲔ ﻣﺘﻌﺎﻣﺪﻳﻦ ﺃﻭ ﺃﻯ ﺷﻜﻞ ﻭﻧﻘﻮﻝ ﺃﻟﻴـﺎﻑ ‪٩٠/١٠‬ﺃﻯ ‪ % ١٠‬ﻣـﻦ‬ ‫ﺍﻷﻟﻴﺎﻑ ﰱ ﺇﲡﺎﻩ ﻭ‪ % ٩٠‬ﰱ ﺍﻻﲡﺎﻩ ﺍﻵﺧﺮ ﻭ ‪ ٥٠/٥٠‬ﺃﻯ ‪ % ٥٠‬ﻣـﻦ ﺍﻷﻟﻴـﺎﻑ ﰱ ﺇﲡـﺎﻩ‬ ‫ﻭ‪ %٥٠‬ﰱ ﺍﻻﲡﺎﻩ ﺍﻵﺧﺮ ﻭﻫﻜﺬﺍ ‪.‬‬ ‫ﺟـ‪ -‬ﻃﺒﻘﺎ ً ﻟﻠﺸﻜﻞ ﻭﺍﳌﻘﺎﺱ ‪:‬‬ ‫* ﺍﻷﻟﻴﺎﻑ ﺍﳌﻄﺤﻮﻧﺔ )‪ :(Milled Fibers‬ﻭﻫﻰ ﺃﻗﺼﺮ ﺍﻷﻟﻴﺎﻑ‬ ‫ﺍﻟﱴ ﺃﺳﺘﺨﺪﻣﺖ ﰱ ﺍﻟﺘﺴﻠﻴﺢ ﻭﻃﻮﳍﺎ ﻳﺘﺮﺍﻭﺡ ﺑﲔ ‪٣٠٠٠-٣٠‬‬ ‫ﻣﻴﻜﺮﻭﻥ ﻭﻧﺴﺒﺔ ‪ L/D‬ﺣﻮﺍﱃ ‪٣٠‬‬ ‫‪١٤٩‬‬


‫* ﺍﻷﻟﻴﺎﻑ ﺍﳌﻘﻄﻌﺔ ﺍﻟﻘﺼﲑﺓ )‪ :(short chopped fibers‬ﻃﻮﳍﺎ ﺣﻮﺍﱃ ‪ ٦‬ﻣﻢ ﻭﻧﺴﺒﺔ ‪L/D‬‬

‫ﺣﻮﺍﱃ ‪ ٨٠٠‬ﻭﺗﻜﻮﻥ ﻣﻘﺎﻭﻣﺘﻬﺎ ﺃﻛﱪ ﻣﻦ ﺍﻷﻟﻴﺎﻑ ﺍﳌﻄﺤﻮﻧﺔ ﻭﺗﻜﻠﻔﺔ ﺗﺼﻨﻴﻌﻬﺎ ﺿﻌﻔﻬﺎ ‪.‬‬ ‫* ﺍﻷﻟﻴﺎﻑ ﺍﳌﻘﻄﻌﺔ ﺍﻟﻄﻮﻳﻠﺔ )‪ :(long chopped fibers‬ﻃﻮﳍﺎ ﺣﻮﺍﱃ ‪٥‬ﺳﻢ ﻭﺗﻀﺎﻑ ﰱ ﺃﻏﻠﺐ‬ ‫ﺍﻷﺣﻴﺎﻥ ﺇﱃ ﺃﻟﻮﺍﺡ ﺍﻟﺰﺟﺎﺝ ﺍﳌﺼﻠﺪﺓ ﻛﻬﺮﺑﺎﺋﻴﹰﺎ ﻟﺰﻳﺎﺩﺓ ﺟﺴﺎﺀﺓ ﺍﻷﺟﺰﺍﺀ ﺍﳌﺼﺒﻮﺑﺔ ﺑﺎﻟﻀﻐﻂ‪.‬‬

‫* ﺍﻷﻟﻴﺎﻑ ﺍﳌﺴﺘﻤﺮﺓ‪ :‬ﻭ ﻫﻰ ﺍﻷﻋﻠﻰ ﺃﺩﺍﺀ ﻭﻭﺯ‪‬ﺎ ﻣﻨﺨﻔﺾ ﻭ ﻳﻨﺘﺞ‬ ‫ﻣﻦ ﺍﻷﻟﻴﺎﻑ ﺍﳌﺴﺘﻤﺮﺓ ﺃﻧﻮﺍﻉ ﻛﺜﲑﺓ ﻣﻨﻬﺎ ﺧﻴﻮﻁ ﺍﻟﻐﺰﻝ ﻭ ﺍﻷﻟﻮﺍﺡ‬ ‫ﻭ ﲢﺘﻮﻯ ﺍﻷﻟﻮﺍﺡ ﻣﻦ ‪ ٤٠٠‬ﺇﱃ ‪ ١٦٠٠٠‬ﺷﻌﲑﺓ ﻣﻨﻔﺮﺩﺓ ﻭ ﻗـﺪ‬ ‫ﻳﺼﻞ ﻋﺮﺽ ﺍﻷﻟﻮﺍﺡ ﺇﱃ ‪١,٥‬ﻡ ﻭ ﺗﺘﻤﻴﺰ ﺍﻷﻟﻴﺎﻑ ﺍﻟﻄﻮﻳﻠﺔ ﲟﻘﺎﻭﻣﺔ‬ ‫ﻋﺎﻟﻴﺔ ﻟﻺﻋﻴﺎﺀ ﻭ ﻣﻘﺎﻭﻣﺔ ﻛﻴﻤﻴﺎﺋﻴﺔ ﺃﻓﻀﻞ ﻣـﻦ ﺃﻟﻴـﺎﻑ ﺍﻟﺰﺟـﺎﺝ‬ ‫ﺧﺼﻮﺻﺎ ﰱ ﺍﻟﺒﻴﺌﺎﺕ ﺍﻟﻘﻠﻮﻳﺔ ﻭ ﻟﻜﻦ ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻠﺼﺪﻡ ﻗﻠﻴﻠﺔ‪.‬‬ ‫* ﻳﻨﺘﺞ ﺃﻳﻀﺎ ً ﺃﺷﻜﺎﻝ ﺃﺧﺮﻯ ﻋﻠﻰ ﺣﺴﺐ ﺍﻟﻐﺮﺽ ﺍﳌﺴﺘﺨﺪﻣﺔ ﻣﻦ ﺃﺟﻠﺔ ﺣﻴﺚ ﻳﺘﻢ ﺗﺸﻜﻴﻠﻬﺎ ﻭﺫﻟﻚ‬ ‫ﻋﻦ ﻃﺮﻳﻖ ﻭﺿﻌﻬﺎ ﰱ ﺍﻟﻨﻤﻮﺫﺝ ﺍﳌﺮﺍﺩ ﺗﺸﻜﻴﻠﻬﺎ ﻋﻠﻰ ﺷﻜﻠﻪ ﰒ ﺭﺷﻬﺎ ﺃﻭ ﺩﻫﺎ‪‬ﺎ ﺑﺎﳌﺎﺩﺓ ﺍﻟـﻼ ﺻـﻘﺔ‬ ‫)ﺇﻳﺒﻮﻛﺴﻰ(‪.‬‬ ‫‪ ٢-٢-٥-٧‬ﳎﺎﻻﺕ ﺍﺳﺘﺨﺪﺍﻡ ﺍﻷﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻧﻴﺔ‬ ‫‪ -١‬ﺍﺳﺘﺨﺪﺍﻣﺎﺕ ﻋﺎﻣﺔ‪:‬‬ ‫ﺍﻷﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻧﻴﺔ ﻭﺍﺣﺪﺓ ﻣﻦ ﺃﺣﺪﺙ ﺍﻟﺘﻘﻨﻴﺎﺕ ﺍﻟﱴ ﻳﺘﻢ ﺇﺳﺘﺨﺪﺍﻣﻬﺎ ﰱ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍﻟـﺼﻨﺎﻋﺎﺕ‬ ‫ﺍﳌﺨﺘﻠﻔﺔ ﻭﻛﺬﻟﻚ ﳍﺎ ﺗﻄﺒﻴﻘﺎﺕ ﰱ ﳎﺎﻝ ﺍﳍﻨﺪﺳﺔ ﺍﳌﺪﻧﻴﺔ ﻭﺳﻮﻑ ﻧﺘﻨﺎﻭﻝ ﺗﻠﻚ ﺍﻻﺳﺘﺨﺪﺍﻣﺎﺕ ﻓﻴﻤـﺎ‬ ‫ﻳﻠﻰ ‪:‬‬ ‫‪ -١‬ﻃﻮﺭﺕ ﰱ ﺍﻷﺳﺎﺱ ﻟﻠﻌﺰﻝ ﺍﳊﺮﺍﺭﻯ ‪.‬‬ ‫‪ -٢‬ﻳﺘﻢ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﻋﻠﻰ ﻧﻄﺎﻕ ﻭﺍﺳﻊ ﰱ ﺻﻨﺎﻋﺔ ﺍﳌﹶﺮﻛﹶﺒﺎﺕ ﺍﻟﻔﻀﺎﺋﻴﺔ ‪.‬‬ ‫‪ -٣‬ﺗﺴﺘﺨﺪﻡ ﺃﻳﻀﹰﺎ ﰱ ﺗﺼﻨﻴﻊ ﻫﻴﺎﻛﻞ ﺍﻟﺴﻴﺎﺭﺍﺕ ‪.‬‬ ‫‪ -٤‬ﰱ ﺗﺼﻨﻴﻊ ﺳﻴﺎﺭﺍﺕ ﻭﺩﺭﺍﺟﺎﺕ ﺍﻟﺴﺒﺎﻕ ﻟﻠﻤﺤﺘﺮﻓﲔ ‪.‬‬ ‫‪ -٥‬ﺍﳌﻌﺪﺍﺕ ﺍﻟﺮﻳﺎﺿﻴﺔ ﻭﺑﻌﺾ ﺍﻷﺷﻴﺎﺀ ﺍﻟﻜﻤﺎﻟﻴﺔ ﺍﻟﺼﻐﲑﺓ‬ ‫ﻭﻳﻨﺘﺞ ﺃﻳﻀﹰﺎ ﺍﺷﻜﺎﻝ ﺃﺧﺮﻯ ﻋﻠﻰ ﺣﺴﺐ ﺍﻟﻐﺮﺽ ﺍﳌﺴﺘﺨﺪﻣﺔ ﻣﻦ ﺃﺟﻠﻪ ﻣﺜﻞ‪:‬‬ ‫ﻣﻮﺍﺳﲑ – ﻛﺎﺑﻼﺕ ﺍﻟﻜﺮﺑﻮﻥ ﻓﺎﻳﱪ ﺃﻟﻮﺍﺡ ﻣﺮﻧﺔ ﺿﻔﺎﺋﺮ ﻭﺟﺪﺍﺋﻞ ﻭﺣﺼﺎﺋﺮ‬ ‫‪١٥٠‬‬


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‫@@@@@@@@@‪@ @Šöb–y@@@@@@@@@@@@@@@@@@@@@@@@@@@@@Ýöa†u@O@ŠöbÐ™@@@@@@@@@@@@@@@@@@@@@@@@òãŠß@aìÛc‬‬

‫‪ -٢‬ﺗﻄﺒﻴﻘﺎﺕ ﰱ ﺍﳍﻨﺪﺳﺔ ﺍﳌﺪﻧﻴﺔ‪:‬‬ ‫ﳎﺎﻻﺕ ﺍﺳﺘﺨﺪﺍﻡ ﺃﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻥ ﰱ ﺍﳋﺮﺳﺎﻧﺔ ﻛﺜﲑﺓ ﻭﻣﺘﻌﺪﺩﺓ ﻭﻣﻨﻬﺎ‪:‬‬

‫* ﺧﺮﺳﺎﻧﺔ ﺃﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻥ ﺍﻟﻘﺼﲑﺓ ‪.‬‬ ‫ﺣﻴﺚ ﻳﺘﻢ ﺍﺿﺎﻓﺔ ﺍﻷﻟﻴﺎﻑ ﺇﱃ ﺑﻌﺾ ﺍﳌﻜﻮﻧﺎﺕ ﺍﻻﻧﺸﺎﺋﻴﺔ ﻟﺰﻳﺎﺩﺓ ﺻﻼﺑﺘﻬﺎ ﻭﻣﻨـﻊ ﺍﻟـﺸﺮﻭﺥ ﻣـﻦ‬ ‫ﺍﳊﺪﻭﺙ ﻭﺗﺘﻤﻴﺰ ﺗﻠﻚ ﺍﻷﻟﻴﺎﻑ ﺍﻟﻘﺼﲑﺓ ﺑﺼﻐﺮ ﺍﻟﻘﻄﺮ ‪ ،‬ﻭﺫﻭ ﻣﺘﺎﻧﺔ ﻋﺎﻟﻴﺔ ﻣﻊ ﺍﳌـﺪﻯ ﺍﻟﻄﻮﻳـﻞ ﰱ‬ ‫ﺍﻟﻮﺳﻂ ﺍﻟﻘﻠﻮﻯ )ﺍﳋﺮﺳﺎﻧﺔ(‪،‬ﻭﺍﻧﻔﻌﺎﻝ ﺍﻻ‪‬ﻴﺎﺭ ‪‬ﺎ ﺃﻛﱪ ﻣﻦ ﺍﻧﻔﻌﺎﻝ ﺍﻻ‪‬ﻴﺎﺭ ﰱ ﺍﳌﻮﻧﺔ ﺍﻷﲰﻨﺘﻴﺔ‪،‬ﻭﺗﻜﻮﻥ‬ ‫ﺫﻭ ﻣﺘﺎﻧﺔ ﻋﺎﻟﻴﺔ ﰱ ﺍﻟﻈﺮﻭﻑ ﺍﻟﻘﺎﺳﻴﺔ ‪ ،‬ﻭﻗﺪ ﰎ ﺍﺳـﺘﺨﺪﺍﻡ ﺃﻟﻴـﺎﻑ ﺍﻟﻜﺮﺑـﻮﻥ ﻛﺒـﺪﻳﻞ ﻷﻟﻴـﺎﻑ‬ ‫ﺍﻷﺳﺒﺴﺘﻮﺱ ﳌﺎ ﳍﺎ ﻣﻦ ﳐﺎﻃﺮ ﺻﺤﻴﺔ ﺧﻄﲑﺓ ‪،‬ﻭﻟﻘﺪ ﻋﻜﻒ ﺍﻟﻴﺎﺑﺎﻧﻴﻮﻥ ﻋﻠﻰ ﺗﻄﻮﻳﺮ ﺧﺮﺳﺎﻧﺔ ﺃﻟﻴـﺎﻑ‬ ‫ﺍﻟﻜﺮﺑﻮﻥ ﺣﱴ ﺃ‪‬ﻢ ﰱ ﻋﺎﻡ ‪ ١٩٩٤‬ﻛﺎﻧﻮﺍ ﻳﺴﺘﺨﺪﻣﻮ‪‬ﺎ ﺑﻜﺜﺎﻓﺔ ﻭﻋﺮﻑ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﳋﺮﺳـﺎﻧﺔ‬ ‫ﺍﻟﻠﻴﻔﻴﺔ ﺑﺈﲰﲔ‪:‬‬ ‫)‪( Carbon fiber cement concrete)(CFCC‬‬ ‫ ﺧﺮﺳﺎﻧﺔ ﺃﲰﻨﺖ ﺃﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻥ‪:‬‬‫ ﺍﳋﺮﺳـﺎﻧﺔ ﺍﳌـﺴﻠﺤﺔ ﺑﺄﻟﻴـﺎﻑ ﺍﻟﻜﺮﺑـﻮﻥ‪(Carbon fiber reinforced concrete) :‬‬‫)‪(CFRC‬‬

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‫* ﺍﺳﺘﺨﺪﺍﻡ ﺍﻷﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻧﻴﺔ ﰱ ﺍﻟﺘﺮﻣﻴﻢ ﻭﺍﻟﺘﺪﻋﻴﻢ‬ ‫* ﺍﺳﺘﺨﺪﺍﻡ ﺃﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻥ ﰱ ﻛﺎﺑﻼﺕ ﺍﻟﺸﺪ ‪.‬‬ ‫ﺇﻥ ﺧﺼﺎﺋﺺ ﺃﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻥ ﻣﻦ ﺧﻔﻪ ﻭﺯﻥ )ﲬﺲ ﻭﺯﻥ ﺍﳊﺪﻳﺪ( ﻭ ﻣﻘﺎﻭﻣﻪ ﻋﺎﻟﻴﺔ ﻟﻠﺸﺪ )ﺃﻛﱪ ﻣﻦ‬ ‫ﺍﳊﺪﻳﺪ( ﻭ ﲢﻤﻞ ﺍﻟﺘﺸﻐﻴﻞ ﺍﻟﻘﺎﺳﻰ ﰱ ﺍﻟﺒﻴﺌﺎﺕ ﺍﳌﺨﺘﻠﻔﺔ ﺳـﺎﻋﺪﺕ ﻋﻠـﻰ ﺗﻄـﻮﻳﺮ ﺍﺳـﺘﺨﺪﺍﻣﻪ ﰱ‬ ‫ﺍﻟﺸﺪﺍﺩﺍﺕ ﻭ ﺍﻟﻜﺎﺑﻼﺕ ﻭ ﺳﺎﻋﺪ ﻋﻠﻰ ﺫﻟﻚ ﺧﻔﻪ ﻭﺯﻧﻪ ﳑﺎ ﺳﻬﻞ ﺍﻟﻌﻤﻞ ﰱ ﺍﳌﻮﻗـﻊ ﻭ ﺳـﻬﻮﻟﺔ ﰱ‬ ‫ﺍﻟﺘﻌﺎﻣﻞ ﻣﻌﻪ ﻭ ﺍﻟﺘﺮﻛﻴﺐ ﻭ ﻛﺬﻟﻚ ﺗﻘﻠﻴﻞ ﺍﻟﺘﺮﺧﻴﻢ ﺍﳊﺎﺩﺙ ﰱ ﺍﻟﻜﺎﺑﻞ ﻭ ﲢﻤﻠﻪ ﻷﲪﺎﻝ ﺃﻛـﱪ ﻣـﻦ‬ ‫ﺗﻠﻚ ﺍﻟﱴ ﺗﺘﺤﻤﻠﻬﺎ ﻛﺎﺑﻼﺕ ﺍﳊﺪﻳﺪ ﳑﺎ ﻳﺴﺎﻋﺪ ﻋﻠﻰ ﺑﻨﺎﺀ ﻛﺒﺎﺭﻯ ﺫﺍﺕ ﲝﻮﺭ ﺃﻛﱪ‪.‬‬ ‫‪@ @´ÜiëŠi@µìjÛa@ÒbîÛc@S@MU@MW‬‬ ‫ﻫﺬﻩ ﺍﻷﻟﻴﺎﻑ ﻣﻦ ﺍﻟﺒﻮﻟﻴﻤﺮﺍﺕ ﺍﳌﺘﻜﻮﻧﺔ ﺑﺎﻹﺿﺎﻓﺔ ﻭﻣﻦ ﺃﻫﻢ ﳑﻴﺰﺍ‪‬ﺎ ﺃ‪‬ﺎ ﻗﻮﻳﺔ ﺟـﺪﹰﺍ ﻭﺗﺘﺤﻤـﻞ ﺍﳌـﻮﺍﺩ‬ ‫ﺍﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﻭﻣﻦ ﺃﻫﻢ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﺍﻟﻌﺎﻣﺔ ﺃ‪‬ﺎ ﺗﺴﺘﺨﺪﻡ ﰱ ﺻـﻨﺎﻋﺔ ﺍﻟـﺴﺠﺎﺩ ﻭﺍﻟـﺸﻜﺎﺋﺮ ﺍﻟﺒﻼﺳـﺘﻴﻚ‬ ‫ﻭﺍﳌﻌﻠﺒﺎﺕ ﻭﺃﻫﻢ ﺍﺳﺘﺨﺪﻣﺘﻬﺎ ﰱ ﺍﻷﻋﻤﺎﻝ ﺍﻻﻧﺸﺎﺋﻴﺔ ﻫﻰ ﻋﻤﻞ ﺷﺒﻜﺔ ﻣﻦ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ ﻭﺍﻟـﱴ‬ ‫ﺗﺴﺘﺨﺪﻡ ﰱ ﺍﻷﻋﻤﺎﻝ ﺍﳋﺮﺳﺎﻧﻴﺔ ﻷﻏﺮﺍﺽ ﳐﺘﻠﻔﺔ‪.‬‬ ‫ﻭﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ ﻋﺒﺎﺭﺓ ﻋﻦ ﺣﺰﻡ ﻣﻦ ﺃﻟﻴﺎﻑ ﻣﺘﻤﺎﺳﻜﺔ ﻣﻊ ﺑﻌﻀﻬﺎ ﻣﺼﻨﻮﻋﺔ ﻣﻦ ﻣﺎﺩﺓ ﺍﻟﺒﻮﱄ‬ ‫ﺑﺮﻭﺑﻠﲔ ﺗﻀﺎﻑ ﺑﻨﺴﺒﺔ ‪ ٠,٩‬ﻛﻴﻠﻮﺟﺮﺍﻡ ﻟﻜﻞ ﻣﺘﺮ ﻣﻜﻌﺐ ﻣﻦ ﺍﳋﺮﺳﺎﻧﺔ ﺃﺛﻨﺎﺀ ﺍﳋﻠـﻂ‪Polyproblin .‬‬ ‫ﺗﺘﻔﻜﻚ ﺍﳊﺰﻡ ﺍﳌﺘﻤﺎﺳﻜﺔ ﺑﻔﻌﻞ ﺍﳋﻠﻂ ﻭﺗﺘﺤﻮﻝ ﺇﱃ ﻣﻼﻳﲔ ﻣﻦ ﺍﻷﻟﻴﺎﻑ ﺍﳌﻨﻔﺼﻠﺔ‪ .‬ﻫﺬﻩ ﺍﻷﻟﻴﺎﻑ ﺗﺘﻮﺯﻉ‬ ‫ﺑﺈﻧﺘﻈﺎﻡ ﺩﺍﺧﻞ ﺍﳋﺮﺳﺎﻧﺔ ﰲ ﲨﻴﻊ ﺍﻹﲡﺎﻫﺎﺕ ﻣﻜﻮﻧﺔ ﺗﻘﻮﻳﺔ ﺇﺿﺎﻓﻴﺔ ﺿﺪ ﺍﻟـﺸﺮﻭﺥ ﺍﻟـﱵ ﺗﻨـﺘﺞ ﻋـﻦ‬ ‫ﺍﻹﻧﻜﻤﺎﺵ ﺃﺛﻨﺎﺀ ﻋﻤﻠﻴﺔ ﺍﻟﺸﻚ‪ ،‬ﻭﻛﻠﻤﺎ ﺃﺧﺬﺕ ﺍﳋﺮﺳﺎﻧﺔ ﰲ ﺍﻟﺸﻚ ﻭﺍﻹﻧﻜﻤـﺎﺵ ﻭﺑـﺪﺃﺕ ﺍﻟـﺸﺮﻭﺥ‬ ‫ﺍﻟﺪﻗﻴﻘﺔ ﺟﺪﺍ" ﰲ ﺍﻟﺘﻜﻮﻥ ﻗﺎﺑﻠﺘﻬﺎ ﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ ﻟﺘﺴﺪﻫﺎ ﻭﲤﻨﻊ ﺗﺄﺛﲑﻫﺎ ﻭﺗﻄﻮﺭﻫﺎ ﻭﺇﻳﻘـﺎﻑ‬ ‫ﺍﳌﺸﺎﻛﻞ ﺍﻟﱵ ﻣﻦ ﺍﳌﻤﻜﻦ ﺃﻥ ﺗﺘﺮﺗﺐ ﻋﻠﻴﻬﺎ ﻭﻫﺬﺍ ﳛﻘﻖ ﻣﺰﺍﻳﺎ ﻧﺬﻛﺮﻫﺎ ﻓﻴﻤﺎ ﻳﻠﻲ‪:‬‬ ‫¾‪@ @´ÜiëŠi@µìjÛa@ÒbîÛc@òØj‘@paŒî‬‬ ‫‪ (١‬ﺍﻟﺘﻘﻠﻴﻞ ﻣﻦ ﻧﻔﺎﺫﻳﺔ ﺍﳋﺮﺳﺎﻧﺔ ﻟﻠﻤﻴﺎﻩ ﺃﺛﺒﺘﺖ ﺍﻟﺘﺠﺎﺭﺏ ﺍﻟﻌﻤﻠﻴﺔ ﺇﻥ ﺇﺿﺎﻓﺔ ﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ‬ ‫ﻟﻠﺨﺮﺳﺎﻧﺔ ﻭﻣﺎ ﻳﺘﺮﺗﺐ ﻋﻠﻴﻪ ﻣﻦ ﺍﳊﺪ ﻣﻦ ﺍﻟﺸﺮﻭﺥ ﺇﱃ ﺣﺪ ﻛﺒﲑ ﻳﺆﺩﻱ ﺇﱃ ﺍﻟﺘﻘﻠﻴـﻞ ﻣـﻦ ﻧﻔﺎﺫﻳـﺔ‬ ‫ﺍﳋﺮﺳﺎﻧﺔ ﻟﻠﻤﻴﺎﻩ ﻭﺗﺒﲔ ﺍﻟﺘﺠﺮﺑﺔ ﻣﻌﺪﻝ ﺍﻟﻨﻔﺎﺫﻳﺔ ﻟﻠﺨﺮﺳﺎﻧﺔ ﰲ ﺣﺎﻟﺔ ﻋﺪﻡ ﻭﺟﻮﺩ ﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒـﻮﱃ‬ ‫ﺑﺮﻭﺑﻠﲔ ﻭﻣﻘﺎﺭﻧﺘﻪ ﰲ ﺣﺎﻟﺔ ﻭﺟﻮﺩ ﻧﺴﺐ ﻣﺘﻔﺎﻭﺗﺔ ﻣﻨﻪ‪.‬‬ ‫‪١٥٢‬‬


‫‪ (٢‬ﺯﻳﺪﺓ ﻣﻘﺎﻭﻣﺔ ﺍﳋﺮﺳﺎﻧﺔ ﻟﻠﺘﺂﻛﻞ ﻭﺍﻹﺣﺘﻜﺎﻙ ﻓﻘﺪ ﺃﺛﺒﺘﺖ ﺍﻟﺘﺠﺎﺭﺏ ﺃﻥ ﺇﺳﺘﺨﺪﺍﻡ ﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒـﻮﱃ‬ ‫ﺑﺮﻭﺑﻠﲔ ﻳﺰﻳﺪ ﻣﻦ ﻣﻘﺎﻭﻣﺔ ﺍﳋﺮﺳﺎﻧﺔ ﻟﻺﺣﺘﻜﺎﻙ ﺑﻨﺴﺒﺔ ‪ %١٠٥‬ﻭﻫﺬﺍ ﻳﻀﺎﻋﻒ ﻣﻦ ﻋﻤﺮ ﺍﳋﺮﺳـﺎﻧﺔ‬ ‫ﺍﻟﱵ ﺗﺘﻌﺮﺽ ﳍﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻷﲪﺎﻝ )ﻣﺜﻞ ﺃﺭﺿﻴﺎﺕ ﺍﳌﺨﺎﺯﻥ ﺍﻟﱵ ﺗﺘﺤﺮﻙ ﻓﻮﻗﻬﺎ ﺍﻷﻭﻧﺎﺵ(‪.‬‬ ‫‪ (٣‬ﺯﻳﺎﺩﺓ ﻣﻘﺎﻭﻣﺔ ﺍﳋﺮﺳﺎﻧﺔ ﻟﻺﻧﺸﻄﺎﺭ‪ ،‬ﺃﺟﺮﻳﺖ ﺍﻟﺘﺠﺎﺭﺏ ﳌﻌﺮﻓﺔ ﺗﺄﺛﲑ ﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ ﻋﻠﻰ‬ ‫ﺍﳋﺮﺳﺎﻧﺔ ﻣﻦ ﺣﻴﺚ ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻺﻧﺸﻄﺎﺭ ﻭﻗﺪ ﺃﺛﺒﺘﺖ ﺍﻟﺘﺠﺎﺭﺏ ﺃﻥ ﺷﺒﻜﺔ ﺃﻟﻴـﺎﻑ ﺍﻟﺒـﻮﱃ ﺑـﺮﻭﺑﻠﲔ‬ ‫ﻳﺴﺎﻋﺪ ﺍﳋﺮﺳﺎﻧﺔ ﻋﻠﻰ ﺍﻹﺣﺘﻔﺎﻅ ﺑﺸﻜﻠﻬﺎ ﻭﻋﺪﻡ ﺍﻹ‪‬ﻴﺎﺭ ﺇﻻ ﺑﻌﺪ ﺃﻛﺜﺮ ﻣﻦ ‪%١٠‬ﻣﻦ ﲪﻞ ﺍﻟﻜـﺴﺮ‬ ‫ﺑﻴﻨﻤﺎ ﺗﻨﻬﺎﺭ ﺍﳋﺮﺳﺎﻧﺔ ﺍﻟﱵ ﻻ ﲢﺘﻮﻱ ﻋﻠﻰ ﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ ﺑﻌﺪ ﺣﺪﻭﺙ ﺍﻟـﺸﺮﺥ ﺍﻷﻭﻝ‬ ‫ﺑﻘﻠﻴﻞ‪ .‬ﻫﺬﻩ ﺍﳋﺎﺻﻴﺔ ﳍﺎ ﺃﳘﻴﺔ ﺧﺎﺻﺔ ﺟﺪﺍ" ﺧﺼﻮﺻﺎ" ﰲ ﺍﳌﻨﺸﺎﺕ ﺍﻟﱵ ﳍﺎ ﺍﺛـﺎﺭ ﻣﺒﺎﺷـﺮﺓ ﻋﻠـﻰ‬ ‫ﺍﻷﺭﻭﺍﺡ ﻭﺍﳌﻤﺘﻠﻜﺎﺕ ﺍﳋﺎﺻﺔ‪.‬‬ ‫‪ (٤‬ﺯﻳﺎﺩﺓ ﻗﻮﺓ ﲢﻤﻞ ﺍﳋﺮﺳﺎﻧﺔ ﻟﻠﺼﺪﻣﺎﺕ ﺣﻴﺚ ﺃﺟﺮﺕ ﺟﺎﻣﻌﺔ ﻛﻮﻟﻮﻣﺒﻴﺎ ﺍﻹﳒﻠﻴﺰﻳﺔ ﲡﺎﺭ‪‬ـﺎ ﺍﻟـﱵ‬ ‫ﺃﺛﺒﺘﺖ ﺃﻥ ﺍﳋﺮﺳﺎﻧﺔ ﺇﺫﺍ ﺃﺿﻴﻔﺖ ﺇﻟﻴﻬﺎ ﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑـﺮﻭﺑﻠﲔ ﺯﺍﺩﺕ ﻗﺎﺑﻠﻴﺘـﻬﺎ ﻻﻣﺘـﺼﺎﺹ‬ ‫ﺍﻟﺼﺪﻣﺎﺕ ﺇﱃ ﺣﺪ ﻛﺒﲑ‪.‬‬ ‫‪ (٥‬ﺗﻘﻠﻴﻞ ﺍﻟﺘﺎﻛﻞ ﰲ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ‪ ،‬ﻣﻌﻈﻢ ﺍﻟﺘﺎﻛﻞ ﺍﻟﺬﻱ ﳛﺪﺙ ﰲ ﺃﺳﻴﺎﺥ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﳛـﺪﺙ‬ ‫ﺑﺴﺒﺐ ﺇﻧﺘﻘﺎﻝ ﺃﻳﻮﻧﺎﺕ ﺍﻟﻜﻠﻮﺭﻳﺪ ﺇﱃ ﺳﻄﺢ ﺍﳊﺪﻳﺪ ﻭﻏﺎﻟﺒﺎ ﻣﺎ ﲢﺪﺙ ﻇﺎﻫﺮﺓ ﺍﻟﺘﺎﻛﻞ ﰲ ﺍﻟﺒﻴﺌﺔ ﺍﻟﺒﺤﺮﻳﺔ‬ ‫ﻭﺍﻟﺼﻨﺎﻋﻴﺔ‪ .‬ﻭﻧﺸﲑ ﻫﻨﺎ ﺇﱃ ﺃﻥ ﲪﺎﻳﺔ ﺳﻄﺢ ﺍﳊﺪﻳﺪ ﻣﻦ ﺍﻟﺘﺎﻛﻞ ﻳﺮﺗﺒﻂ ﺇﺭﺗﺒﺎﻃﺎ ﻣﺒﺎﺷﺮﺍ" ﲜﻮﺩﺓ ﺍﻟﻘﺸﺮﺓ‬ ‫ﺍﳋﺎﺭﺟﻴﺔ ﻟﻠﺨﺮﺳﺎﻧﺔ‪ .‬ﻭﻫﻨﺎ ﻳﺄﰐ ﺍﻟﺪﻭﺭﺍﳌﻬﻢ ﻟﺸﺒﻜﺔ ﺃﻟﻴـﺎﻑ ﺍﻟﺒـﻮﱃ ﺑـﺮﻭﺑﻠﲔ ﺣﻴـﺚ ﺃﻥ ﻗـﺪﺭﺓ‬ ‫ﺍﻟﻜﻠﻮﺭﻳﺪﺍﺕ ﻋﻠﻰ ﺇﺧﺘﺮﺍﻕ ﺍﳋﺮﺳﺎﻧﺔ ﻟﻠﻮﺻﻮﻝ ﺇﱃ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﻣﻦ ﺧﻼﻝ ﺍﻟﺸﺮﻭﺥ ﺳﻮﻑ ﺗﻜﻮﻥ‬ ‫ﳏﺪﻭﺩﺓ ﺟﺪﺍ"‪.‬‬ ‫‪ (٦‬ﻻ ﻳﺘﻄﻠﺐ ﺃﻱ ﺗﻌﺪﻳﻞ ﻋﻠﻰ ﺍﻟﺘﺼﻤﻴﻢ ﻭﻣﻦ ﺍﳋﻮﺍﺹ ﺍﳍﺎﻣﺔ ﻟﺸﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ ﺃﻧـﻪ ﻻ‬ ‫ﻳﺆﺛﺮ ﻋﻠﻰ ﺃﻱ ﻣﻦ ﺍﳋﻮﺍﺹ ﺍﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﻟﻠﻮﺍﺩ ﺍﻟﺪﺍﺧﻠﻴﺔ ﰲ ﺗﺮﻛﻴﺐ ﺍﳋﺮﺳـﺎﻧﺔ ﺣﻴـﺚ ﺃﻥ ﺗﺄﺛﲑﻫـﺎ‬ ‫ﻣﻴﻜﺎﻧﻴﻜﻲ ﻓﻘﻂ‪ ،‬ﻫﺬﺍ ﻭﺗﻌﺘﱪ ﺃﻧﺴﺠﺔ ﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ ﻫﻲ ﺃﺣﺴﻦ ﺃﻧﻮﺍﻉ ﺍﻷﻧﺴﺠﺔ ﺍﻟـﱵ‬ ‫ﺗﻀﺎﻑ ﺇﱃ ﺍﳋﺮﺳﺎﻧﺔ ﺣﻴﺚ ﺃ‪‬ﺎ ﺧﺎﻣﻠﺔ ﻭﻻ ﺗﺘﻔﺎﻋﻞ ﻣﻊ ﻣﻜﻮﻧﺎﺕ ﺍﳋﺮﺳﺎﻧﺔ ﻭﺑﺎﻟﻄﺒﻊ ﻓﻬﻲ ﻻ ﺗﺘﺎﻛـﻞ‬ ‫ﻛﻤﺎ ﺃ‪‬ﺎ ﺧﻔﻴﻔﺔ ﺍﻟﻮﺯﻥ ﻭﻫﻲ ﻧﺎﺟﺤﺔ ﺟﺪﺍ" ﻣﻊ ﲨﻴﻊ ﺃﻧﻮﺍﻉ ﺍﳋﻠﻄﺎﺕ ﻭﺩﻭﻥ ﺃﻥ ﳛﺘﺎﺝ ﺇﺿـﺎﻓﺘﻬﺎ ﺇﱃ‬ ‫ﺗﻐﲑ ﺃﻭ ﺗﻌﺪﻳﻞ ﰲ ﺍﻟﻨﺴﺐ ﻟﻠﻤﻮﺍﺩ ﺍﳌﻜﻮﻧﺔ ﻟﻠﺨﻠﻄﺔ‪ .‬ﻛﻤﺎ ﺃﻥ ﺇﺿﺎﻓﺔ ﺃﻱ ﻛﻤﻴﺔ ﺯﺍﺋﺪﺓ ﻣﻦ ﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ‬ ‫ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ ﻻ ﻳﺆﺩﻱ ﺇﱃ ﺃﻱ ﻣﺸﺎﻛﻞ ﻓﻨﻴﺔ‪.‬‬ ‫‪١٥٣‬‬


‫‪ (٧‬ﺑﺪﻳﻞ ﻧﺎﺟﺢ ﻟﺸﺒﻜﺔ ﺍﻟﺘﺴﻠﻴﺢ ﺍﻟﺜﺎﻧﻮﻳﺔ‪ ،‬ﲤﺜﻞ ﺷﺒﻜﺔ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﺍﻟﺴﻄﺤﻴﺔ ﻟﻸﺳﻘﻒ ﻭﺍﻷﺭﺿـﻴﺎﺕ‬ ‫ﻣﺸﻜﻠﺔ ﻷ‪‬ﺎ ﲢﺘﺎﺝ ﺇﱃ ﺿﺒﻂ ﻭﻫﺬﺍ ﻳﺘﻄﻠﺐ ﺃﻳﺪﻱ ﻋﺎﻣﻠﺔ ﻭﺗﻜﻠﻔﺔ ﺯﺍﺋﺪﺓ ﻭﻟﻜﻦ ﰲ ﻭﺟـﻮﺩ ﺷـﺒﻜﺔ‬ ‫ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ ﻓﻠﻴﺴﺖ ﻫﻨﺎﻙ ﺣﺎﺟﺔ ﺇﱃ ﺷﺒﻜﺔ ﺍﳊﺪﻳﺪ ﺍﻟﺴﻄﺤﻴﺔ ﻭﺫﻟﻚ ﺑﻨﺎﺀ ﻋﻠﻰ ﺍﻟﺘﺠـﺎﺭﺏ‬ ‫ﺍﳌﺴﺘﻔﻴﻀﺔ ﺍﻟﱵ ﺃﺟﺮﻳﺖ ﰲ ﻣﻌﺎﻣﻞ ﺍﻷﲝﺎﺙ ﻭﺍﻹﺧﺘﺒﺎﺭﺍﺕ ﻭﺍﻟﱵ ﺃﺛﺒﺘﺖ ﺃﻥ ﺍﺳﺘﺒﺪﺍﻝ ﺷـﺒﻜﺔ ﺣﺪﻳـﺪ‬ ‫ﺍﻟﺘﺴﻠﻴﺢ ﺍﻟﺜﺎﻧﻮﻳﺔ ﺍﻟﺴﻄﺤﻴﺔ ﳑﻜﻦ ﺑﺈﺳﺘﺨﺪﺍﻡ ﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ ﻣﻊ ﺍﶈﺎﻓﻈﺔ ﻋﻠـﻰ ﻧﻔـﺲ‬ ‫ﺍﳋﻮﺍﺹ ﺍﻟﻔﻨﻴﺔ ﻭﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﻷﺻﻠﻴﺔ‪.‬‬ ‫©‪@ @ZÕîjĐnÛa@püb‬‬ ‫ﻳﺴﺘﺨﺪﻡ ﺷﺒﻜﺔ ﺃﻟﻴﺎﻑ ﺍﻟﺒﻮﱃ ﺑﺮﻭﺑﻠﲔ ﰲ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍ‪‬ﺎﻻﺕ ﻣﺜـﻞ ﲪﺎﻣـﺎﺕ ﺍﻟـﺴﺒﺎﺣﺔ ﻭﺍﻟﻜﺒـﺎﺭﻱ‬ ‫ﻭﺍﻟﻘﻨﻮﺍﺕ ﻭﺍﻷﻧﻔﺎﻕ ﻭﰲ ﺍﳌﺨﺎﺯﻥ ﺍﻟﱵ ﺗﺘﻄﻠﺐ ﺃﺭﺿﻴﺎﺕ ﳍﺎ ﻣﻘﺎﻭﻣﺔ ﻋﺎﻟﻴﺔ ﻟﻺﺣﺘﻜـﺎﻙ ﻧﻈـﺮﺍ" ﳊﺮﻛـﺔ‬ ‫ﺍﻷﻭﻧﺎﺵ ﻓﻮﻗﻬﺎ ﻭﺑﺸﻜﻞ ﻋـﺎﻡ ﳝﻜـﻦ ﺍﻟﻘـﻮﻝ ﺑﺄﻧـﻪ ﳝﻜـﻦ ﺇﺳـﺘﺨﺪﺍﻣﻪ ﰲ ﲨﻴـﻊ ﺍﻟﺘﻄﺒﻴﻘـﺎﺕ‪.‬‬ ‫ﻣﺎﺩﺓ ﺍﳌﻴﻜﺮﻭﺳﻴﻠﻴﻜﺎ ﺗﻌﻤﻞ ﻋﻠﻰ ﲢﺴﲔ ﻣﻘﺎﻭﻣﺎﺕ ﻭﻣﻮﺍﺻﻔﺎﺕ ﺍﳋﺮﺳـﺎﻧﺔ ﻭ ﺗﻄﺒﻴﻘﺎ‪‬ـﺎ ﰲ ﺍﻷﻋﻤـﺎﻝ‬ ‫ﺍﻹﻧﺸﺎﺋﻴﺔ ‪ .‬ﺣﻴﺚ ﻟﺪﻯ ﺍﳉﺰﻳﺌﺎﺕ ﺍﻟﺼﻐﲑﺓ ﺟﺪﺍ ﺍﳌﻜﻮﻧﺔ ﳌﺎﺩﺓ " ﺍﳌﺎﻳﻜﺮﻭﺳﻴﻠﻴﻜﺎ" ﺍﳌﻘﺪﺭﺓ ﻋﻠﻰ ﺍﺧﺘـﺮﺍﻕ‬ ‫ﺍﻟﻔﺮﺍﻏﺎﺕ ﺑﲔ ﺟﺰﻳﺌﺎﺕ ﺍﻻﲰﻨﺖ ﺍﳌﻌﺠﻮﻥ ﻭﺍﳊﺼﻰ ﳑﺎ ﻳﻌﻤـﻞ ﻋﻠـﻰ ﲢـﺴﲔ ﺧـﻮﺍﺹ ﺍﳊـﺸﻮﺓ ‪.‬‬ ‫ﻛﻤﺎ ﻳﺘﻔﺎﻋﻞ ﺛﺎﱐ ﺃﻛﺴﻴﺪ ﺍﻟﺴﻴﻠﻴﻜﻮﻥ ﻣﻊ ﻫﻴﺪﺭﻭﻛﺴﻴﺪ ﺍﻟﻜﺎﻟﺴﻴﻮﻡ ﻟﻴﺨﺺ ﻣﻨﻪ ﺑﺸﻜﻞ ﻫﻴﺪﺭﺍﺕ ﺍﲰﻨﺘﻴﺔ‬ ‫ﻟﺘﺸﻜﻞ ﺍﻟﻜﺜﲑ ﻣﻦ ﻫﻴﺪﺭﺍﺕ ﺳﻴﻠﻴﻜﺎﺕ ﺍﻟﻜﺎﻟﺴﻴﻮﻡ ‪ CSH‬ﻭﺍﻟﱵ ﺗﻀﻢ ﺍﻻﲰﻨﺖ ﻣﻌًﹰﺎ ﺣﻴﺚ ﻳﺆﺩﻱ ﺫﻟﻚ‬ ‫ﻟﺰﻳﺎﺩﺓ ﻗﻮﺓ ﺍﳋﺮﺳﺎﻧﺔ ﻭﺟﻌﻠﻬﺎ ﺃﻗﻞ ﻧﻔﺎﺫﻳﺔ‬ ‫‪@ @†îß‰þa@ÒbîÛc@TMUMW‬‬ ‫ﻭﺗﻌﺘﱪ ﺃﻟﻴﺎﻑ ﺍﻷﺭﻣﻴﺪ ﺍﻷﺣﺪﺙ ﻭﺍﻷﻋﻠﻰ ﻟﻠﺘﻜﻠﻔﺔ‪ ،‬ﻭﻧﻈﺮﹰﺍ ﻟﻠﻜﻠﻔﺔ ﺍﻟﻌﺎﻟﻴﺔ ﻟﻸﻟﻴـﺎﻑ ﻓﺈ‪‬ـﺎ ﻏﺎﻟﺒـﹰﺎ ﻣـﺎ‬ ‫ﻼ ﻗﺪ ﰎ ﺍﺳﺘﺨﺪﺍﻡ ﺃﻟﻴﺎﻑ ﺍﻷﺭﻣﻴـﺪ ﰲ ﺗـﺪﻋﻴﻢ‬ ‫ﺗﺴﺘﺨﺪﻡ ﻟﺘﺪﻋﻴﻢ ﺍﳌﻨﺸﺂﺕ ﰱ ﺍﳊﺎﻻﺕ ﺍﳍﺎﻣﺔ ﺟﺪﹰﺍ ﻓﻤﺜ ﹰ‬ ‫ﺍﳌﻨﺸﺂﺕ ﺍﻟﱴ ﺗﻀﺮﺭﺕ ﰱ ﺍﻟﺰﻟﺰﺍﻝ‪ ،‬ﻛﻤﺎ ﰎ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﰱ ﺗﺪﻋﻴﻢ ﺍﳌﻨﺸﺂﺕ ﺍﻷﺛﺮﻳﺔ‪.‬‬

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‫‪:(, . 4'8( "( 6-7‬‬

‫ﻋﻨﺪ ﻭﺿﻊ ﺍﻷﻟﻴﺎﻑ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﺍﻟﺒﻮﻟﻴﻤﺮﻳﺔ )ﺍﳌﻨﻈﻮﻣﺔ ﺍﻟﺮﺋﻴﺴﻴﺔ( ﻓﺈ‪‬ـﺎ ﺗﺘﺤـﻮﻝ ﺇﱃ ﻣـﺎﺩﺓ ﻣﺮﻛﺒـﺔ‬ ‫)‪ (Composite Material‬ﻭﺍﳌﺎﺩﺓ ﺍﳌﺮﻛﺒﺔ ﻫﻰ ﺍﳌﺎﺩﺓ ﺍﻟﱴ ﺗﺘﻜﻮﻥ ﻋﻠﻰ ﺍﻷﻗﻞ ﻣﻦ ﻣﺎﺩﺗﲔ ﳐﺘﻠﻔـﺘﲔ‬ ‫ﻭﻳﻌﻤﻼﻥ ﻣﻌﹰﺎ ﻛﻤﺎﺩﺓ ﻭﺍﺣﺪﺓ ﺟﺪﻳﺪﺓ ﳍﺎ ﺧﺼﺎﺋﺺ ﺟﺪﻳﺪﺓ ﳐﺘﻠﻔﺔ ﻋﻦ ﺧﺼﺎﺋﺺ ﻛﻞ ﻣﺎﺩﺓ ﻋﻠﻰ ﺣﺪﻩ ‪،‬‬ ‫ﻭﻋﻤﻠﻴﹰﺎ ﻣﻌﻈﻢ ﺍﳌﻮﺍﺩ ﺍﳌﺮﻛﺒﺔ ﺗﺘﻜﻮﻥ ﻣـﻦ ﻣـﺎﺩﺓ ﺃﺳﺎﺳـﻴﺔ ﻭﻳﻄﻠـﻖ ﻋﻠﻴﻬـﺎ ﺍﳌﻨﻈﻮﻣـﺔ ﺍﻟﺮﺋﻴـﺴﻴﺔ‬ ‫)‪ ( Matrix‬ﻭﻣﺎﺩﺓ ﺃﺧﺮﻯ ﻓﺮﻋﻴﺔ ﺗﻀﺎﻑ ﻋﻠﻴﻬﺎ ﻟﺘﻜﺴﺐ ﺍﳌﻨﻈﻮﻣﺔ ﺯﻳﺎﺩﺓ ﰱ ﺍﳌﻘﺎﻭﻣﺔ ﻭﺍﳉﺴﺎﺋﺔ ‪،‬ﻭﻫﺬﻩ‬ ‫ﺍﳌﺎﺩﺓ ﺍﻟﻔﺮﻋﻴﺔ ﻏﺎﻟﺒﹰﺎ ﻣﺎ ﺗﻜﻮﻥ ﻋﻠﻰ ﻫﻴﺌﺔ ﺃﻟﻴﺎﻑ )‪ (Fiber Form‬ﻭﺍﻟﻴـﻮﻡ ﺃﺷـﻬﺮ ﺍﳌـﻮﺍﺩ ﺍﳌﺮﻛﺒـﺔ‬ ‫ﺍﺳﺘﻌﻤﺎ ﹰﻻ ﳝﻜﻦ ﺃﻥ ﺗﻘﺴﻢ ﺍﱃ ﺛﻼﺙ ﳎﻤﻮﻋﺎﺕ ﺭﺋﻴﺴﻴﺔ ﻭﻫﻰ ‪:‬‬ ‫‪ -١‬ﻣﻨﻈﻮﻣﺔ ﺍﳌﺮﻛﺒﺎﺕ ﺍﻟﺒﻮﻟﻴﻤﺮﻳﺔ‬

‫)‪Polymer matrix composites (PMC's‬‬

‫ﻭﻳﻄﻠﻖ ﻋﻠﻴﻬﺎ ﺃﻳﻀﹰﺎ ﺑﻮﻟﻴﻤﺮﺍﺕ ﺍﻷﻟﻴﺎﻑ ﺍﳌﺴﻠﺤﺔ )‪ (FRP‬ﻭﻫﻰ ﺍﺧﺘـﺼﺎﺭ )‬

‫‪Fiber Reinforced‬‬

‫‪ (Polymers‬ﻭﻫﻨﺎ ﻳﺘﻢ ﺍﺳﺘﺨﺪﺍﻡ ﺍﻟﺒﻮﻟﻴﻤﺮ ﺍﳌﻌﺎﰿ ﺑﺎﳌﻮﺍﺩ ﺍﻟﺮﺍﺗﻨﺠﻴـﺔ ﻛﻤـﺎﺩﺓ ﺃﺳﺎﺳـﻴﺔ )‪(Matrix‬‬ ‫ﻭﺍﻟﺘﻘﻮﻳﺔ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﻷﻟﻴﺎﻑ ﺳﻮﺍﺀ ﺍﻷﻟﻴﺎﻑ ﺍﻟﺰﺟﺎﺟﻴﺔ ﺃﻭﺃﻟﻴﺎﻑ ﺍﻟﻜﺮﺑﻮﻥ ﺃﻭ ﺍﻷﺭﻣﻴﺪ ﻛﻤﺎﺩﺓ ﻓﺮﻋﻴﺔ ‪.‬‬ ‫‪ -٢‬ﻣﻨﻈﻮﻣﺔ ﺍﳌﺮﻛﺒﺎﺕ ﺍﳌﻌﺪﻧﻴﺔ‬

‫)‪Metal matrix composites (MMC's‬‬

‫ﻭﻳﻮﺟﺪ ﺑﻜﺜﺮﺓ ﰱ ﺻﻨﺎﻋﺔ ﺍﳌﹶﺮﻛﹶﺒﺎﺕ ﻭﻫﻨﺎ ﻳﺘﻢ ﺍﺳﺘﺨﺪﺍﻡ ﺍﳌﻌﺎﺩﻥ ﻣﺜﻞ ﺍﻷﻟﻮﻣﻨﻴـﻮﻡ ﻛﻤـﺎﺩﺓ ﺃﺳﺎﺳـﻴﺔ‬ ‫)‪ (Matrix‬ﻭﺍﻟﺘﻘﻮﻳﺔ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﻷﻟﻴﺎﻑ ﻣﺜﻞ ﺃﻟﻴﺎﻑ ﺍﻟ )‪. (Silicon Carbide‬‬ ‫‪ -٣‬ﻣﻨﻈﻮﻣﺔ ﺍﳌﺮﻛﺒﺎﺕ ﺍﻟﺴﲑﺍﻣﻜﻴﺔ‬

‫)‪Ceramic matrix composites (CMC's‬‬

‫ﻭﻳﺘﻢ ﺍﺳﺘﺨﺪﺍﻣﻪ ﰱ ﺍﻟﺒﻴﺌﺔ ﺫﺍﺕ ﺩﺭﺟﺎﺕ ﺍﳊﺮﺍﺭﺓ ﺍﳌﺮﺗﻔﻌﺔ ﺟﺪﹰﺍ ﻭﻫﻨﺎ ﻳﺘﻢ ﺍﺳﺘﺨﺪﺍﻡ ﺍﻟﺴﲑﺍﻣﻴﻚ ﻛﻤﺎﺩﺓ‬ ‫ﺃﺳﺎﺳﻴﺔ ﻭﺍﻟﺘﻘﻮﻳﺔ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﻷﻟﻴﺎﻑ ﺍﻟﻘﺼﲑﺓ ﺍﳌﺼﻨﻮﻋﺔ ﻣﻦ ﻛﺮﺑﻴﺪ ﺍﻟﺴﻴﻠﻴﻜﻮﻥ )‪.(Silicon Carbide‬‬

‫ﻭﻣﻦ ﻧﺎﺣﻴﺔ ﺃﺧﺮﻯ ﻳﺘﻢ ﲢﺪﻳﺪ ﺧﺼﺎﺋﺺ ﺍﳌﺎﺩﺓ ﺍﳌﺮﻛﺒﺔ )‪ (Composite‬ﻣﻦ ﺣﻴﺚ ‪:‬‬ ‫‪ - ١‬ﺧﺼﺎﺋﺺ ﺍﻷﻟﻴﺎﻑ ﺍﳌﺴﺘﺨﺪﻣﺔ ‪.‬‬ ‫‪ -٢‬ﺧﺼﺎﺋﺺ ﺍﻟﺮﺍﺗﻨﺞ )ﺧﻮﺍﺹ ﻣﻴﻜﺎﻧﻴﻜﻴﺔ – ﻣﻘﺎﻭﻣﺔ ﺍﻟﺘﺂﻛﻞ – ﺍﻟﺘﻤﺎﺳﻚ ﻭﺍﻹﻟﺘﺤﺎﻡ( ‪.‬‬ ‫‪ -٣‬ﺍﻟﻨﺴﺒﺔ ﺑﲔ ﺍﻷﻟﻴﺎﻑ ﻭﺍﻟﺮﺍﺗﻨﺞ ﰱ ﺍﳌﻨﻈﻮﻣﺔ‪.‬‬

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‫ﻛﻤﺎ ﺃﻧﻪ ﳚﺐ ﺃﻥ ﻳﻜﻮﻥ ﺳﻄﺢ ﺍﻟﺘﻼﻣﺲ ﺑﲔ ﺍﻷﻟﻴﺎﻑ ﻭﺍﳌﻨﻈﻮﻣﺔ ﺍﳌﺪﻋﻤﺔ ﺑﺎﻷﻟﻴﺎﻑ ﻧـﺎﻋﻢ ﻭﻣـﺴﺘﻮﻯ‬ ‫ﻭﺍﳌﻄﻠﻮﺏ ﺃﻥ ﻳﻨﺘﻘﻞ ﺍﳊﻤﻞ ﻣﻦ ﺍﳌﻨﻈﻮﻣﺔ ﺍﱃ ﺍﻷﻟﻴﺎﻑ ﻋﻦ ﻃﺮﻳﻖ ﺳﻄﺢ ﺍﻟﺘﻼﻣﺲ ﺑﻴﻨﻬﻢ ﻭﻫﺬﺍ ﻳﻌﲎ ﺃﻧﻪ‬ ‫ﻣﻦ ﺍﳌﻬﻢ ﺃﻥ ﺗﻜﻮﻥ ﻣﺴﺎﺣﺔ ﺍﻟﺘﻼﻣﺲ ﻛﺒﲑﺓ ﻭﺃﻥ ﺗﻜﻮﻥ ﻫﻨﺎﻙ ﻗﻮﺓ ﲤﺎﺳﻚ ﻛﺒﲑﺓ ﺑﻴﻨﻬﻤﺎ ﻭﻣﻦ ﺍﺷـﻜﺎﻝ‬ ‫ﺍﻻ‪‬ﻴﺎﺭ ﺃﻥ ﳛﺪﺙ ﺍﻻ‪‬ﻴﺎﺭ ﻋﻨﺪ ﺳﻄﺢ ﺍﻟﺘﻼﻣﺲ ﻭﻳﺴﻤﻰ ﰱ ﻫﺬﻩ ﺍﳊﺎﻟـﺔ )‪ (Debonding‬ﻭﻟـﺬﻟﻚ‬ ‫ﻛﺎﻥ ﻣﻦ ﺍﻟﻀﺮﻭﺭﻯ ﻗﻴﺎﺱ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺴﻄﺢ ﺍﻟﻔﺎﺻﻞ ﺃﻭ ﺳﻄﺢ ﺍﻟﺘﻼﻣﺲ ﻟﻼ‪‬ﻴﺎﺭ‪.‬‬ ‫*********‬

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‫ﻳﻌﺮﻑ ﺍﻟﺘﺂﻛﻞ ﺑﺄﻧﻪ ﺍﳓﻼﻝ ﺍﳌﻌﺪﻥ ﺑﺴﺒﺐ ﺗﻔﺎﻋﻠﻪ ﻣﻊ ﺍﻟﻮﺳﻂ ﺍﻟﺬﻱ ﻳﺘﻌﺮﺽ ﻟﻪ ﺃﻭ ﻓﺸﻞ ﺍﳌﻌـﺪﻥ ﺑـﺄﻱ‬ ‫ﺳﺒﺐ ﻏﲑ ﺍﻟﺴﺒﺐ ﺍﳌﻴﻜﺎﻧﻴﻜﻲ ﺍﻟﺒﺤﺖ ‪ ،‬ﺃﻭ ﻳﻌﺮﻑ ﺃﺣﻴﺎﻧﹰﺎ ﺑﺄﻧﻪ ﺍﻟﻌﻤﻠﻴﺔ ﺍﻟﻌﻜﺴﻴﺔ ﻻﺳﺘﺨﻼﺹ ﺍﳌﻌﺪﻥ ﻣﻦ‬ ‫ﺧﺎﻣﺎﺗﻪ ﻭﺍﻟﺘﺂﻛﻞ ﻓﺸﻞ ﻳﺼﻴﺐ ﺳﻄﺢ ﺍﳌﻌﺪﻥ ﻳﻨﺘﺞ ﺑﺴﺒﺐ ﻋﻮﺍﻣﻞ ﻛﻴﻤﻴﺎﺋﻴﺔ ﺃﻭ ﺑﺴﺒﺐ ﻋﻮﺍﻣﻞ ﻛﻴﻤﻴﺎﺋﻴـﺔ‬ ‫ﺗﺴﺎﻋﺪﻫﺎ ﻋﻮﺍﻣﻞ ﻣﻴﻜﺎﻧﻴﻜﻴﺔ ﻣﺘﻮﻓﺮﺓ ﰲ ﺍﻟﻮﺳﻂ ﺍﻟﺬﻱ ﻳﻌﻤﻞ ﻓﻴﻪ ﺍﳌﻌﺪﻥ‪ .‬ﻭﺍﻷﻣﺜﻠﺔ ﻋﺪﻳﺪﺓ ﻣﻨـﻬﺎ ﺻـﺪﺃ‬ ‫ﻫﻴﻜﻞ ﺍﻟﺴﻴﺎﺭﺓ ﻭﻋﻠﺐ ﺍﳌﻮﺍﺩ ﺍﻟﻐﺬﺍﺋﻴﺔ ﻭﺍﻟﺼﻔﺎﺋﺢ ﻭﺍﳌﻘﺎﻃﻊ ﺍﻟﻔﻮﻻﺫﻳﺔ ﻭﺗﺄﻛﻞ ﺍﻷﻧﺎﺑﻴﺐ ﺍﳌﺪﻓﻮﻧﺔ ﰲ ﺍﻟﺘﺮﺑﺔ‬ ‫‪ ،‬ﻭﻫﻨﺎﻙ ﺃﻣﺜﻠﺔ ﺃﺧﺮﻯ ﻋﻠﻰ ﺗﺂﻛﻞ ﺃﺟﺰﺍﺀ ﻣﻌﺪﻧﻴﺔ ﻋﺪﻳﺪﺓ ﺗﺘﻌﺮﺽ ﺇﱃ ﺃﻭﺳﺎﻁ ﺻﻨﺎﻋﻴﺔ ﻣﺜـﻞ ﺍﻷﲪـﺎﺽ‬ ‫ﻭﺍﻟﻘﻮﺍﻋﺪ ﻭﺍﳌﻴﺎﻩ ﺍﳌﺎﳊﺔ ﻭﻣﺎ ﺇﱃ ﻏﲑ ﺫﻟﻚ ‪ .‬ﻭ ﳛﺪﺙ ﺍﻟﺘﺂﻛﻞ ﺗﻠﻒ ﺷﺪﻳﺪ ﰲ ﺍﳌﻨﺸﺂﺕ ﳑﺎ ﻳﻨـﺘﺞ ﻋﻨـﻪ‬ ‫ﺗﻜﺎﻟﻴﻒ ﺿﺨﻤﺔ ﺗﺘﻤﺜﻞ ﰲ ﻓﻮﺍﻓﺪ ﺍﻹﻧﺘﺎﺝ ﻭ ﺑﺎﻟﺘﺎﱄ ﻗﻠﺔ ﺍﻟﻜﻔﺎﺀﺓ ﺑﺎﻹﺿﺎﻓﺔ ﺇﱃ ﺗﻜﺎﻟﻴﻒ ﺍﻹﺣﻼﻝ ﻭ ﺗﻄﺒﻴﻖ‬ ‫ﺃﺳﺎﻟﻴﺐ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺘﺂﻛﻞ ﺇﻥ ﺍﻷﺿﺮﺍﺭ ﺍﻟﱵ ﻳﺴﺒﺒﻬﺎ ﺍﻟﻔﺸﻞ ﺍﻟﺴﻄﺤﻲ ﺑﺴﺒﺐ ﺍﻟﺘﺂﻛﻞ ﻋﺪﻳﺪﺓ ﻭﲨﻴﻌﻬﺎ ﺫﺍﺕ‬ ‫ﻣﺮﺩﻭﺩ ﺍﻗﺘﺼﺎﺩﻱ ﺳﻲﺀ ‪ ،‬ﻭﻣﻦ ﻫﺬﻩ ﺍﻷﺿﺮﺍﺭ‬ ‫‪@ @òîØîãbØî½a@ãìä@æa†ÔÏë@…bÈi⁄a@Ìm@MQ‬‬ ‫ﻳﺆﺩﻱ ﺍﻟﺘﺂﻛﻞ ﺇﱃ ﻓﻘﺪﺍﻥ ﺍﻟﻮﺯﻥ ﺑﺴﺒﺐ ﺍﳓﻼﻝ ﺍﳌﻌﺪﻥ ﻭﺑﺎﻟﺘﺎﱄ ﺇﱃ ﺗﻐﲑ ﺃﺑﻌـﺎﺩﻩ ‪ ،‬ﻟـﺬﻟﻚ ﺗﻌﻄـﻰ ﰲ‬ ‫ﻚ‬ ‫ﺍﻟﻐﺎﻟﺐ ﺑﻌﺾ ﺍﻻﻋﺘﺒﺎﺭﺍﺕ ﻟﻠﺘﺂﻛﻞ ﻋﻨﺪ ﻭﺟﻮﺩﻩ ﻭﻋﻨﺪ ﺍﻟﺘﺼﻤﻴﻢ ﻭﺗﻜﻮﻥ ﻫﺬﻩ ﺍﻻﻋﺘﺒﺎﺭﺍﺕ ﺯﻳﺎﺩﺓ ﺍﻟﺴﻤ ‪‬‬ ‫ﰲ ﺍﻷﻭﺳﺎﻁ ﺍﻟﱵ ﻳﻜﻮﻥ ﻓﻴﻬﺎ ﻣﻌﺪﻻﺕ ﺍﻟﺘﺂﻛﻞ ﻋﺎﻟﻴﺔ ﻣﻨﻬﺎ ﰲ ﺍﻷﻭﺳﺎﻁ ﺍﻟﱵ ﻳﻜﻮﻥ ﻓﻴﻬﺎ ﻣﻌﺪﻻﺕ ﺍﻟﺘﺂﻛﻞ‬ ‫ﻣﻨﺨﻔﻀﺔ ‪ .‬ﻭﻟﺘﻐﲑ ﺃﺑﻌﺎﺩ ﺍﻟﻘﻄﻌﺔ ﺍﳌﻌﺪﻧﻴﺔ ﺑﺴﺒﺐ ﺍﻟﺘﺂﻛﻞ ﺗﺄﺛﲑ ﰲ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴـﺔ ‪ ،‬ﺣﻴـﺚ ﺗﻘـﻞ‬ ‫ﻗﺎﺑﻠﻴﺘﻬﺎ ﻟﺘﺤﻤﻞ ﺍﻷﲪﺎﻝ ﺍﳋﺎﺭﺟﻴﺔ ‪ ،‬ﺃﻱ ﺗﺰﺩﺍﺩ ﻗﺎﺑﻠﻴﺘﻬﺎ ﻟﻠﺘﺸﻮﻳﻪ ﺍﻟﻠﺪﻥ ‪ .‬ﺇﻥ ﺍﺳﺘﺨﺪﺍﻡ ﺍﳌﻌﺪﻥ ﰲ ﺃﻭﺳﺎﻁ‬ ‫ﻣﺴﺎﻋﺪﺓ ﻋﻠﻰ ﺍﻟﺘﺂﻛﻞ ﻳﻮﺩﻱ ﺇﱃ ﺍﳔﻔﺎﺽ ﻗﻴﻢ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍﳋﻮﺍﺹ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻭﺧﺼﻮﺻﹰﺎ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ‬ ‫ﻟﻠﻜﻼﻝ ﻭﻧﺸﻮﺀ ﺍﻟﺘﺸﻘﻘﺎﺕ ﺍﻟﱵ ﺗﺆﺩﻱ ﺇﱃ ﺣﺼﻮﻝ ﺍﻟﻜﺴﺮ ﺍﳍﺶ ﺍﻟﺴﺮﻳﻊ‪.‬‬ ‫‪@ @@ŠèÄ½a@MR‬‬ ‫ﻳﺘﺄﺛﺮ ﻣﻈﻬﺮ ﺍﳌﻌﺪﻥ ﺑﺪﺭﺟﺔ ﻛﺒﲑﺓ ﻋﻨﺪ ﺇﺻﺎﺑﺘﻪ ﺑﺎﻟﺘﺂﻛﻞ ﺣﻴﺚ ﻳﻈﻬﺮ ﺍﳌﻌﺪﻥ ﺩﺍﺋﻤﹰﺎ ﲟﻈﻬﺮ ﺳﻲﺀ ‪ .‬ﻟﺬﺍ ﳚﺐ‬ ‫ﺍﺳﺘﺨﺪﺍﻡ ﻣﻌﺎﺩﻥ ﻣﻘﺎﻭﻣﺔ ﻟﻠﺘﺂﻛﻞ ﺍﳉﻮﻱ ﻣﺜﻞ ﺍﻷﳌﻨﻴﻮﻡ ﺃﻭ ﺍﻟﻔﻮﻻﺫ ﺍﳌﻘﺎﻭﻡ ﻟﻠﺼﺪﺃ ﺑـﺪ ﹰﻻ ﻣـﻦ ﺍﻟﻔـﻮﻻﺫ‬ ‫ﺍﻟﻜﺮﺑﻮﱐ ‪ ،‬ﻛﻤﻮﺍﺩ ﺑﻨ ﹾﺎﺀ ﻇﺎﻫﺮﻳﺔ ﻣﺜﻞ ﻣﻘﺎﻃﻊ ﺍﻟﺸﺒﺎﺑﻴﻚ ﻭﻣﻮﺍﺩ ﻭﺧﺼﻮﺻﹰﺎ ﰲ ﻭﺍﺟﻬﺎﺕ ﺍﻷﺑﻨﻴﺔ ﺍﳋﺎﺭﺟﻴﺔ‬ ‫ﻭﻳﻌﺰﻯ ﺍﳌﻈﻬﺮ ﺍﳊﺴﻦ ﳍﺬﻩ ﺍﳌﻮﺍﺩ ﺇﱃ ﻣﻘﺎﻭﻣﺘﻬﺎ ﻟﻠﺘﺂﻛﻞ ﺍﳉﻮﻱ ‪ .‬ﺃﻣﺎ ﺍﳌﻌﺎﺩﻥ ﺫﺍﺕ ﺍﳌﻘﺎﻭﻣـﺔ ﺍﻟـﻀﻌﻴﻔﺔ‬ ‫ﻟﻠﺘﺂﻛﻞ ﻓﺈ‪‬ﺎ ﺗﻄﻠﻰ ﺑﺄﻧﻮﺍﻉ ﺍﻟﻄﻼﺀ ﺍﳌﺨﺘﻠﻔﺔ ﻟﺘﺤﺴﲔ ﻣﻈﻬﺮﻫﺎ ﻣﻦ ﺧﻼﻝ ﺍﳊﺪ ﻣﻦ ﺗﺂﻛﻠﻬﺎ ‪.‬‬ ‫‪١٥٧‬‬


‫‪@ @ZòîöbÓìÛa@paõaŠu⁄a@kji@òí…b–nÓüa@‰aŠ™þa@MS‬‬ ‫ﺇﻥ ﺍﻷﺿﺮﺍﺭ ﺍﻻﻗﺘﺼﺎﺩﻳﺔ ﺍﻟﻨﺎﲡﺔ ﻋﻦ ﺍﻟﺘﺂﻛﻞ ﻋﺪﻳﺪﺓ ﻭﻣﻬﻤﺔ ‪ ،‬ﺣﻴﺚ ﻳﺴﺒﺐ ﻫﺬﺍ ﺍﻟﻔﺸﻞ ﰲ ﻛـﺜﲑ ﻣـﻦ‬ ‫ﺍﻷﺣﻴﺎﻥ ﺗﻮﻗﻒ ﺍﳌﺼﺎﻧﻊ ﻋﻦ ﺍﻟﻌﻤﻞ ﺗﻮﻗﻒ ﻏﲑ ﻣﱪﻣﺞ ‪ ،‬ﻭﻣﺎ ﻳﻮﺍﻓﻖ ﺫﻟﻚ ﻣﻦ ﻛﻠﻒ ﺍﻗﺘﺼﺎﺩﻳﺔ ﺇﺿـﺎﻓﻴﺔ‬ ‫ﻏﲑ ﻣﺘﻮﻗﻌﺔ ‪ .‬ﻛﺬﻟﻚ ﻓﺈﻥ ﺣﺼﻮﻝ ﺍﻟﺘﺂﻛﻞ ﻳﺆﺩﻱ ﺇﱃ ﺍﺭﺗﻔﺎﻉ ﻛﻠﻒ ﺍﻟﺼﻴﺎﻧﺔ ﺍﻟﺪﻭﺭﻳﺔ ﺣﻴﺚ ﻳﺘﻄﻠـﺐ ﰲ‬ ‫ﻛﺜﲑ ﻣﻦ ﺍﳊﺎﻻﺕ ﺗﺒﺪﻳﻞ ﺍﳉﺰﺀ ﺍﳌﻌﺪﱐ ﺍﻟﺘﺎﻟﻒ ﲜﺰﺀ ﺟﺪﻳﺪ ﺁﺧﺮ ‪.‬ﻭ‪‬ﺬﺍ ﺍﳋﺼﻮﺹ ﻳﻜـﻮﻥ ﺑﺎﻹﻣﻜـﺎﻥ‬ ‫ﺃﺣﻴﺎﻧﹰﺎ ﺗﻮﻓﲑ ﺑﻌﺾ ﺍﳌﺒﺎﻟﻎ ﻋﻨﺪ ﺍﺧﺘﻴﺎﺭ ﻣﺎﺩﺓ ﻣﻌﺪﻧﻴﺔ ﺫﺍﺕ ﻣﻘﺎﻭﻣﺔ ﺗﺂﻛﻞ ﺃﻋﻠﻰ ﻟﺘﺼﻨﻴﻊ ﻫﺬﺍ ﺍﳉﺰﺀ ﺍﻟﺘﺎﻟﻒ‬ ‫‪ .‬ﻭﺗﺘﻮﻓﺮ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍﻷﻣﺜﻠﺔ ﺍﻟﱵ ﺗﺸﲑ ﺇﱃ ﺃﻥ ﺍﺧﺘﻴﺎﺭ ﻣﺎﺩﺓ ﻋﺎﻟﻴﺔ ﺍﻟﺘﻜـﺎﻟﻴﻒ ﻧـﺴﺒﻴﹰﺎ ‪ ،‬ﻭﻟﻜﻨـﻬﺎ ﺫﺍﺕ‬ ‫ﻣﻘﺎﻭﻣﺔ ﺟﻴﺪﺓ ﻟﻠﺘﺂﻛﻞ ﻣﻦ ﺍﻟﻨﺎﺣﻴﺔ ﺍﻻﻗﺘﺼﺎﺩﻳﺔ ﺃﻓﻀﻞ ﻣﻦ ﺍﺳﺘﺨﺪﺍﻡ ﻣﺎﺩﺓ ﻣﻌﻴﻨﺔ ﺃﺭﺧـﺺ ﲦﻨـﹰﺎ ﻭﻟﻜﻨـﻬﺎ‬ ‫ﺗﺘﻌﺮﺽ ﻟﻠﺘﻠﻒ ﺍﻟﺴﺮﻳﻊ ﺑﺴﺒﺐ ﺍﻟﺘﺂﻛﻞ ‪ ،‬ﳑﺎ ﻳﺘﻄﻠﺐ ﻋﻨﺪﺋﺬ ﺗﻐﻴﲑﻩ ﺑﺼﻮﺭﺓ ﺩﻭﺭﻳﺔ ﻭﰲ ﻛﻠﺘـﺎ ﺍﳊـﺎﻟﺘﲔ‬ ‫ﻳﻼﺣﻆ ﺑﺄﻥ ﺍﻟﺘﺂﻛﻞ ﻳﺴﺒﺐ ﺃﺿﺮﺍﺭﹰﺍ ﺍﻗﺘﺼﺎﺩﻳﺔ ﺑﺴﺒﺐ ﺯﻳﺎﺩﺓ ﺍﻟﺘﻜﺎﻟﻴﻒ ‪ .‬ﻛﻤﺎ ﺃﻥ ﺍﻹﺟﺮﺍﺀﺍﺕ ﺍﻟﻮﻗﺎﺋﻴـﺔ‬ ‫ﻟﻠﺤﺪ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ﺗﺪﺧﻞ ﺿﻤﻦ ﻛﻠﻒ ﺍﻟﺘﺸﻐﻴﻞ ﻭﺍﻟﺼﻴﺎﻧﺔ‪ ٠‬ﺇﻥ ﺍﻟﺘﺂﻛﻞ ﻳﺆﺩﻱ ﺃﺣﻴﺎﻧﹰﺎ ﺇﱃ ﺣﺪﻭﺙ ﻓـﺸﻞ‬ ‫ﻏﲑ ﻣﺘﻮﻗﻊ ﰲ ﺍﻷﺟﺰﺍﺀ ﺍﳌﻌﺪﻧﻴﺔ ﻭﻫﻨﺎ ﺗﻜﻤﻦ ﺃﺳﺎﺳﹰﺎ ﺧﻄﻮﺭﺓ ﻣﺸﻜﻠﺔ ﺍﻟﺘﺂﻛﻞ ‪ ،‬ﺣﻴﺚ ﺃﻥ ﺣﻮﺍﺩﺙ ﺍﻟﻔﺸﻞ‬ ‫ﺑﺼﻮﺭﺓ ﻣﻔﺎﺟﺌﺔ ﻗﺪ ﻳﺆﺩﻱ ﺇﱃ ﺣﺼﻮﻝ ﺃﺿﺮﺍﺭ ﻛﺒﲑﺓ ﺃﻛﱪ ﻣﻦ ﺗﻠﻚ ﺍﻟﱵ ﻳﺴﺒﺒﻬﺎ ﺍﻟﺘﺂﻛﻞ ﺍﳌﺘﻮﻗﻊ ﺣﺼﻮﻟﻪ‬ ‫‪ .‬ﻭﰲ ﻫﺬﺍ ﺍﳌﻀﻤﺎﺭ ﳚﺐ ﺍﻟﻮﻗﻮﻑ ﺑﺪﻗﺔ ﻋﻠﻰ ﻣﻌﺪﻻﺕ ﺍﻟﺘﺂﻛﻞ ﰲ ﺍﻷﺟﺰﺍﺀ ﺍﳌﻌﺪﻧﻴﺔ ﻭﺫﻟﻚ ﻋـﻦ ﻃﺮﻳـﻖ‬ ‫ﺍﻟﻘﻴﺎﺳﺎﺕ ﺍﳌﺴﺘﻤﺮﺓ ﻭﺍﻟﺪﻭﺭﻳﺔ ﳌﻌﺪﻻﺕ ﺍﻟﺘﺂﻛﻞ ﻭﺍﻟﻔﺤﺺ ﺍﳌﺴﺘﻤﺮ ﻟﻠﻘﻄﻊ ﺍﳌﻌﺪﻧﻴﺔ ﻻﲣﺎﺫ ﺍﻹﺟـﺮﺍﺀﺍﺕ‬ ‫ﺍﻟﻮﻗﺎﺋﻴﺔ ﻗﺒﻞ ﻭﺻﻮﻝ ﺩﺭﺟﺔ ﺍﻟﺘﺂﻛﻞ‬ ‫‪@ @òßýÛa@æa†ÔÏ@MT‬‬ ‫ﻳﺆﺩﻱ ﺍﻟﺘﺂﻛﻞ ﺃﺣﻴﺎﻧﹰﺎ ﺃﻭ ﰲ ﻛﺜﲑ ﻣﻦ ﺍﻷﺣﻴﺎﻥ ﺇﱃ ﺣﺼﻮﻝ ﻛﻮﺍﺭﺙ ﺇﺫﺍ ﱂ ﺗﺘﺨﺬ ﺍﻹﺟـﺮﺍﺀﺍﺕ ﺍﻟﻮﻗﺎﺋﻴـﺔ‬ ‫ﻼ ﺍﻟﺘﻌﺎﻣﻞ ﻣﻊ ﺍﳌﻮﺍﺩ ﺍﳋﻄـﺮﺓ ﻣﺜـﻞ ﺍﻟﻐـﺎﺯﺍﺕ ﺍﻟـﺴﺎﻣﺔ ﻭﺣـﺎﻣﺾ‬ ‫ﺍﻟﻜﻔﻴﻠﺔ ﺑﺈﻳﻘﺎﻓﻪ ﺃﻭ ﺍﳊﺪ ﻣﻨﻪ ﻓﻤﺜ ﹰ‬ ‫ﺍﳍﻴﺪﺭﻭﻓﻠﻮﺭﻳﻚ ﻭﺍﻷﲪﺎﺽ ﺍﳌﺮﻛﺰﺓ ﻣﺜﻞ ﺣﺎﻣﺾ ﺍﻟﻜﱪﻳﺘﻴﻚ ﻭﺍﻟﻨﻴﺘﺮﻳﻚ ﻭﺍﳌﻮﺍﺩ ﺍﻟﻘﺎﺑﻠﺔ ﻟﻼﺷﺘﻌﺎﻝ ﻭﺍﳌﻮﺍﺩ‬ ‫ﺍﳌﺸﻌﺔ ﻭﺍﳌﻮﺍﺩ ﺍﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﰲ ﺩﺭﺟﺎﺕ ﺣﺮﺍﺭﺓ ﻋﺎﻟﻴﺔ ﻭﻋﻨﺪ ﺿﻐﻂ ﻋﺎﱄ ﻳﺘﻄﻠﺐ ﺍﺳﺘﻌﻤﺎﻝ ﻣـﻮﺍﺩ ﻣﻌﺪﻧﻴـﺔ‬ ‫ﻣﻌﻴﻨﺔ ﻻ ﺗﺘﺂﻛﻞ ﺑﺪﺭﺟﺔ ﻛﺒﲑﺓ ﰲ ﻣﺜﻞ ﻫﺬﻩ ﺍﻟﻈﺮﻭﻑ ‪ .‬ﻭﰲ ﻛﺜﲑ ﻣﻦ ﺍﻷﺣﻴﺎﻥ ﻳﺆﺩﻱ ﺣﺼﻮﻝ ﺗﺂﻛـﻞ ﰲ‬ ‫ﺟﺰﺀ ﻣﻌﺪﱐ ﺻﻐﲑ ﺇﱃ ﺍ‪‬ﻴﺎﺭ ﺃﻭﺳﻘﻮﻁ ﻣﻨﺸﺄ ﻛﺎﻣﻞ ‪ ،‬ﻭﻗﺪ ﺗﺴﺒﺐ ﻧﻮﺍﺗﺞ ﺍﻟﺘﺂﻛﻞ ﺃﺣﻴﺎﻧﹰﺎ ﺇﱃ ﲢﻮﻝ ﻣـﻮﺍﺩ‬ ‫ﻏﲑ ﻣﻀﺮﺓ ﺇﱃ ﻣﻮﺍﺩ ﻣﺘﻔﺠﺮﺓ ‪ .‬ﻭﰲ ﻫﺬﺍ ﺍ‪‬ﺎﻝ ﻫﻨﺎﻙ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍﻋﺘﺒﺎﺭﺍﺕ ﺍﻟﺴﻼﻣﺔ ﺍﻟﺼﺤﻴﺔ ﻣﺜﻞ ﺗﻠﻮﺙ‬ ‫ﻣﺎﺀ ﺍﻟﺸﺮﺏ ﺑﺴﺒﺐ ﺗﺂﻛﻞ ﺍﻷﻧﺎﺑﻴﺐ ﺃﻭ ﺧﺰﺍﻧﺎﺕ ﺍﳌﻴﺎﻩ ﻭﻛﺬﻟﻚ ﻳﻠﻌﺐ ﺍﻟﺘﺂﻛﻞ ﺩﻭﺭﹰﺍ ﻣﻬﻤﹰﺎ ﻭﺭﺋﻴـﺴﻴﹰﺎ ﰲ‬ ‫ﺍﺧﺘﻴﺎﺭ ﻧﻮﻉ ﺍﳌﻮﺍﺩ ﺍﳌﻌﺪﻧﻴﺔ ﺍﻟﱵ ﺗﺼﻨﻊ ﻣﻨﻬﺎ ﺍﻷﺟﺰﺍﺀ ﺍﳌﻌﺪﻧﻴﺔ ﺍﻟﱵ ﺗﺴﺘﺨﺪﻡ ﺩﺍﺧﻞ ﺟﺴﻢ ﺍﻹﻧﺴﺎﻥ ﻣﺜـﻞ‬ ‫ﺍﻟﺼﻔﺎﺋﺢ ﺍﻟﻄﺒﻴﺔ ﻭﺻﻤﺎﻣﺎﺕ ﺍﻟﻘﻠﺐ ﻭﻏﲑ ﺫﻟﻚ‪ .‬ﻭﳝﻜﻦ ﺗﻠﺨﻴﺺ ﺍﻷﺿﺮﺍﺭ ﺍﻟـﱵ ﻳـﺴﺒﺒﻬﺎ ﺍﻟﺘﺂﻛـﻞ ﺇﱃ‬ ‫ﺍﻟﺘﻜﺎﻟﻴﻒ ﻣﺘﻤﺜﻠﺔ ﰲ ﺗﻜﺎﻟﻴﻒ ﺍﻹﺣﻼﻝ ﻭﺗﻄﺒﻴﻖ ﺃﺳﺎﻟﻴﺐ ﻣﻘﻮﻣﺔ ﺍﻟﺘﺂﻛﻞ ﻭﻫﺬﻩ ﺍﻟﺘﻜﺎﻟﻴﻒ ﺗﺸﻤﻞ ﺗﻜﺎﻟﻴﻒ‬ ‫ﻣﺒﺎﺷﺮﺓ ﻭﺗﻜﺎﻟﻴﻒ ﻏﲑ ﻣﺒﺎﺷﺮﺓ‪٠‬‬ ‫‪١٥٨‬‬


‫ ‪ :‬‬

‫‪ .١‬ﺍﻧﺘﻬﺎﺀ ﺍﻟﻌﻤﺮ ﺍﻻﻓﺘﺮﺍﺿﻲ ﻟﻠﻤﻌﺪﺓ )ﺗﻠﻒ ﻛﻠﻰ( ‪.‬‬ ‫‪ .٢‬ﺗﻜﺎﻟﻴﻒ ﻋﻤﻠﻴﺔ ﺍﳊﻤﺎﻳﺔ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ﻭ ﺗﻨﻘﺴﻢ ﺇﱃ‪:‬‬ ‫) ﺗﻜﺎﻟﻴﻒ ﺍﳌﻮﺍﺩ ﺍﳌﺎﻧﻌﺔ ﻟﻠﺘﺂﻛﻞ ‪ -‬ﺗﻜﺎﻟﻴﻒ ﺍﳊﻤﺎﻳﺔ ﺍﻟﻜﺎﺛﻮﺩﻳﺔ(‬ ‫‪ .٣‬ﺗﻌﺪﻳﻞ ﻣﻮﺍﺩ ﺍﻟﺘﺼﻨﻴﻊ ﺑﺎﺳﺘﺨﺪﺍﻡ ﻣﻮﺍﺩ ﺃﻛﺜﺮ ﻣﻘﺎﻭﻣﺔ ﻟﻠﺘﺂﻛﻞ ﻭ ﺃﻋﻠﻰ ﺗﻜﻠﻔﺔ ‪.‬‬ ‫‪ .٤‬ﺯﻳﺎﺩﺓ ﺍﻟﺘﺼﻤﻴﻢ ‪ :‬ﻋﻤﻠﻴﺔ ﺍﻟﺰﻳﺎﺩﺓ ﰲ ﺍﻟﺘﺼﻤﻴﻢ ﺗﻜﻮﻥ ﻣﺘﻤﺜﻠﺔ ﰲ ﺯﻳﺎﺩﺓ ﺍﻟﺴﻤﻚ ﻋﻦ ﺍﳊﺪ ﺍﻟﻌﺎﺩﻱ‬ ‫ﻭ ﺫﻟﻚ ﻹﻃﺎﻟﺔ ﻋﻤﺮ ﺍﳌﻌﺪﺓ ﻟﻠﺤﻤﺎﻳﺔ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ﻛﻤﺎ ﺃﻥ ﻋﻤﻠﻴﺔ ﺍﻟﺰﻳﺎﺩﺓ ﰲ ﺍﻟﺘﺼﻤﻴﻢ ﺗـﺆﺩﻯ ﺇﱃ‬ ‫ﺯﻳﺎﺩﺓ ﺍﳌﻜﺎﻥ ﺍﳌﻄﻠﻮﺏ ﻟﻠﻤﻌﺪﺓ ﻭ ﻫﺬﺍ ﰲ ﺣﺪ ﺫﺍﺗﻪ ﻳﻌﺘﱪ ﺯﻳﺎﺩﺓ ﰲ ﺍﻟﺘﻜﺎﻟﻴﻒ ‪.‬‬ ‫! ‪ $ "# :‬‬

‫‪ : ñ@ õbÐØÛa@—Ôã .١‬ﺗﺆﺩﻯ ﻋﻤﻠﻴﺎﺕ ﺍﻟﺘﺂﻛﻞ ﺇﱃ ﺗﻘﻠﻴﻞ ﻛﻔﺎﺀﺓ ﺍﳌﻌﺪﺍﺕ ﺃﻭ ﺍﳋﻄﻮﻁ ﻭ ﺫﻟﻚ ﻧﺘﻴﺠـﺔ‬ ‫ﺗﺮﺍﻛﻢ ﻧﻮﺍﺗﺞ ﺍﻟﺘﺂﻛﻞ ﺣﻴﺚ ﻳﺆﺩﻯ ﺫﻟﻚ ﰲ ﺑﻌﺾ ﺍﻷﺣﻴﺎﻥ ﺇﱃ ﺯﻳﺎﺩﺓ ﺍﻟﻘﻮﺓ ﺍﳌﻄﻠﻮﺑـﺔ ﻟـﺪﻓﻊ‬ ‫ﺍﻟﺴﺎﺋﻞ ﺩﺍﺧﻞ ﺍﳋﻄﻮﻁ ﻭ ﻛﺬﻟﻚ ﺗﻘﻠﻴﻞ ﺍﳊﻴﺰ ﺍﻟﻼﺯﻡ ﳌﺮﻭﺭ ﺍﻟﺴﺎﺋﻞ ﻭ ﳝﻜﻦ ﺃﻥ ﻳﺆﺩﻯ ﺗـﺮﺍﻛﻢ‬ ‫ﺍﻟﺘﺂﻛﻞ ﺇﱃ ﺗﻘﻠﻴﻞ ﺍﻻﻧﺘﻘﺎﻝ ﺍﳊﺮﺍﺭﻱ ﻣﻦ ﺧﻼﳍﺎ ﺃﻭ ﺇﻧﺘﺎﺝ ﻣﻨﺘﺠﺎﺕ ﻣﻌﻴﺒﺔ ‪.‬‬ ‫‪: x@ b;nã⁄a@ÝîÜÔm@ .٢‬ﻋﻤﻠﻴﺎﺕ ﺍﻹﺻﻼﺡ ﻭ ﺍﻟﺘﺠﺪﻳﺪ ﺍﻟﱵ ﲡﺮﻯ ﻟﻸﺟﺰﺍﺀ ﺍﳌﺘﺂﻛﻠﺔ ﻣـﻦ ﺍﳌﻌـﺪﺍﺕ‬ ‫ﲢﺘﺎﺝ ﺇﱃ ﺇﻳﻘﺎﻑ ﺍﳌﺼﻨﻊ ﺃﻭ ﺍﻟﻮﺣﺪﺓ ﳌﺪﺓ ﻣﻌﻴﻨﺔ ﺣﱴ ﺇﺫﺍ ﻛﺎﻥ ﺳﻌﺮ ﺗﻠﻚ ﺍﻷﺟﺰﺍﺀ ﺻﻐﲑﹰﺍ ﻛﻤـﺎ‬ ‫ﺃﻥ ﺯﻳﺎﺩﺓ ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ ﻳﺆﺩﻯ ﰲ ﻛﺜﲑ ﻣﻦ ﺍﻷﺣﻴﺎﻥ ﺇﱃ ﺣﺪﻭﺙ ﺇﻳﻘﺎﻓﺎﺕ ﺍﺿﻄﺮﺍﺭﻳﺔ ﳑﺎ ﻳﺆﺩﻯ‬ ‫ﺇﱃ ﺯﻳﺎﺩﺓ ﻋﻤﻠﻴﺎﺕ ﺍﻟﺼﻴﺎﻧﺔ ﻟﻠﻤﻌﺪﺍﺕ ﻭﻭﻗﻒ ﻋﻤﻠﻴﺎﺕ ﺍﻹﻧﺘﺎﺝ ﳌﺪﺩ ﺃﻃﻮﻝ ﻣﻦ ﺍﻟﻼﺯﻡ ﻭ ﻫـﺬﺍ‬ ‫ﺍﻟﺘﻮﻗﻒ ﻳﺆﺩﻯ ﺇﱃ ﺯﻳﺎﺩﺓ ﺍﻟﺘﻜﺎﻟﻴﻒ ﻭ ﻧﻘﺺ ﺍﻹﻧﺘﺎﺝ ‪.‬‬ ‫‪ : ò@ ;ßbÈÛa@ñ‰bä .٣‬ﺍﻟﺘﺂﻛﻞ ﳝﻜﻦ ﺃﻥ ﻳﺆﺩﻯ ﺇﱃ ﺣﺪﻭﺙ ﺧﻄﻮﺭﺓ ﻋﻠﻰ ﺃﺭﻭﺍﺡ ﺍﻟﻌﺎﻣﻠﲔ ﺑﺎﻟﻮﺣﺪﺓ‬ ‫ﺃﻭ ﺍﳌﺼﻨﻊ ﻭ ﻫﺬﻩ ﺧﺴﺎﺭﺓ ﻏﲑ ﳏﺴﻮﺑﺔ ﰲ ﺍﻟﺘﺼﻤﻴﻢ ﻭ ﻟﻜﻦ ﳚﺐ ﺃﻥ ﺗﺆﺧﺬ ﰱ ﺍﻻﻋﺘﺒﺎﺭ‪.‬‬ ‫‪ : Ý×fnÛa@wmaìäi@tìÜnÛa .٤‬ﺑﻌﺾ ﺍﻟﺼﻨﺎﻋﺎﺕ ﻣﺜﻞ ﺍﻟﺼﻨﺎﻋﺎﺕ ﺍﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﺃﻭ ﺻﻨﺎﻋﺔ ﺍﻷﻏﺬﻳـﺔ ﻻ‬ ‫ﺗﺴﻤﺢ ﺑﺘﻠﻮﺙ ﻣﻨﺘﺠﺎ‪‬ﺎ ﺑﺄﻛﺴﻴﺪ ﺍﳌﻌﺪﻥ ﻭﻟﺘﺠﻨﺐ ﻫﺬﺍ ﺍﻟﺘﻠﻮﺙ ﺍﻟﻨﺎﺗﺞ ﻋﻦ ﺍﻟﺘﺂﻛﻞ ﻓﺈﻧـﻪ ﻳـﺘﻢ‬ ‫ﺗﺼﻨﻴﻊ ﺍﻷﻭﻋﻴﺔ ﻭ ﺍﳋﻄﻮﻁ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﻟﺬﻱ ﻻ ﻳﺼﺪﺃ ‪.‬‬

‫‪١٥٩‬‬


‫‪ & $ 2-8‬‬

‫ﺍﻟﺘﺂﻛﻞ ‪ -:‬ﻫﻮ ﺭﺩ ﻓﻌﻞ ﻛﻬﺮﻭﻛﻴﻤﻴﺎﺋﻰ ﻟﻠﻤﻌﺎﺩﻥ ﺍﶈﺎﻃﺔ ﲟﻮﺍﺩ ﻛﻴﻤﻴﺎﺋﻴﺔ ﻣﻦ ﺍﻟﺘﺮﺑﺔ ﺃﻭ ﻣـﺎﺀ ﻭ ﻫـﺬﻩ‬ ‫ﺗﺸﻜﻞ ﺧﻼﻳﺎ ﺗﻮﺻﻴﻞ ﺗﻮﻟﺪ ﺍﻟﻜﻬﺮﺑﺎﺀ ﻧﺘﻴﺠﺔ ﻓﺮﻕ ﺍﳉﻬﺪ ﺍﻟﻄﺒﻴﻌﻲ ﺑﲔ ﺍﳌﻌﺎﺩﻥ ﻭ ﺍﻟﺬﻯ ﻳﻨـﺘﺞ ﻋﻨـﻪ‬ ‫ﺫﻭﺑﺎﻥ ﺍﳌﻌﺪﻥ ﺍﻷﻛﺜﺮ ﻧﺸﺎﻃﹰﺎ ‪.‬‬ ‫ ‪: ( ' :‬‬

‫‪ .١‬ﻻﺑﺪ ﻣﻦ ﻭﺟﻮﺩ ﻗﻄﱯ ﺍﻟﺘﻔﺎﻋﻞ )ﺍﻵﻧﻮﺩ ‪ -‬ﺍﻟﻜﺎﺛﻮﺩ( ‪.‬‬ ‫‪ .٢‬ﺍﻵﻧﻮﺩ )ﺍﻟﻘﻄﺐ ﺍﳌﻮﺟﺐ( ‪ -:‬ﻣﻌﺪﻥ ﻟﻪ ﻣﺴﺘﻮﻯ ﺃﻋﻠﻰ ﻣﻦ ﺍﻟﻄﺎﻗﺔ )ﺍﻟﻘﻴﻤﺔ ﺍﳌﻄﻠﻘـﺔ ﻟﻔـﺮﻕ‬ ‫ﺍﳉﻬﺪ( ﻭ ﻳﻨﺴﺎﺏ ﻣﻨﻪ ﺍﻟﺘﻴﺎﺭ ﺧﻼﻝ ﺍﻟﺘﺮﺑﺔ ﻭ ﻫﻮ ﺍﳉﺴﻢ ﺍﻟﺬﻱ ﳛﺪﺙ ﻟﻪ ﺍﻟﺘﺂﻛـﻞ ‪.‬ﺍﻟﻜـﺎﺛﻮﺩ‬ ‫)ﺍﻟﻘﻄﺐ ﺍﻟﺴﺎﻟﺐ( ‪ -:‬ﻣﻌﺪﻥ ﻟﻪ ﻣﺴﺘﻮﻯ ﺃﻗﻞ ﻣﻦ ﺍﻟﻄﺎﻗﺔ )ﺍﻟﻘﻴﻤﺔ ﺍﳌﻄﻠﻘﺔ ﻟﻔـﺮﻕ ﺍﳉﻬـﺪ( ﻭ‬ ‫ﻳﻨﺴﺎﺏ ﻣﻨﻪ ﺍﻟﺘﻴﺎﺭ ﺧﻼﻝ ﺳﻠﻚ ﺍﻟﺘﻮﺻﻴﻞ ﻭ ﻫﻮ ﺍﳉﺴﻢ ﺍﻟﺬﻱ ﻳﺘﻢ ﲪﺎﻳﺘﻪ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ‪.‬‬ ‫‪ .٣‬ﻻﺑﺪ ﻣﻦ ﻭﺟﻮﺩ ﻓﺮﻕ ﺟﻬﺪ ﻛﻬﺮﰊ ﺑﲔ ﺍﻟﻜﺎﺛﻮﺩ ﻭ ﺍﻵﻧﻮﺩ ﻻ ﻳﻘﻞ ﻋﻦ ‪ ٥٠‬ﻣﻠﻠﻲ ﻓﻮﻟﺖ ) ﻫـﺬﺍ‬ ‫ﺍﻟﻔﺮﻕ ﻳﺘﻮﻟﺪ ﻧﺘﻴﺠﺔ ﻟﻌﺪﺓ ﺃﺳﺒﺎﺏ ﻣﺜﻞ ﺍﺧﺘﻼﻑ ﺍﻟﺘﺮﻛﻴﺰﺍﺕ ﺃﻭ ﺍﺧﺘﻼﻑ ﺍﳌـﻮﺍﺩ ﺃﻭ ﺍﺧـﺘﻼﻑ‬ ‫ﻧﺴﺐ ﺍﻷﻛﺴﻮﺟﲔ … ﺍﱁ ( ‪.‬‬ ‫‪ .٤‬ﻻﺑﺪ ﻣﻦ ﻭﺟﻮﺩ ﺍﺗﺼﺎﻝ ﻣﻌﺪﱐ ﺃﻭ ﻣﺎﺩﻱ ﺑﲔ ﺍﻵﻧﻮﺩ ﻭ ﺍﻟﻜﺎﺛﻮﺩ ﻳﺴﺎﻋﺪ ﻋﻠـﻰ ﻣـﺮﻭﺭ ﺍﻟﺘﻴـﺎﺭ‬ ‫ﺍﻟﻜﻬﺮﰊ ﻣﻦ ﺧﻼﻟﻪ ‪.‬‬ ‫ﻼ ﻣﻦ ﺍﻵﻧﻮﺩ ﻭ ﺍﻟﻜﺎﺛﻮﺩ ﻭ ﳚﺐ ﺃﻥ ﺗﺘﻮﻓﺮ ﰲ ﻫﺬﺍ ﺍﻟﻮﺳـﻂ‬ ‫‪ .٥‬ﻻﺑﺪ ﻣﻦ ﻭﺟﻮﺩ ﻭﺳﻂ ﻳﻨﻐﻤﺲ ﺑﻪ ﻛ ﹰ‬ ‫ﺍﳌﻮﺻﻠﻴﺔ ﺍﻟﻜﻬﺮﺑﻴﺔ‪.‬‬ ‫‪ .٦‬ﰲ ﺣﺎﻟﺔ ﺗﻮﺍﻓﺮ ﺗﻠﻚ ﺍﻟﺸﺮﻭﻁ ﳎﺘﻤﻌﺔ ﺗﺘﻜﻮﻥ ﺧﻠﻴﺔ ﺍﻟﺘﺂﻛﻞ ﻭ ﻳﺒﺪﺃ ﺍﳌﻌﺪﻥ ﰱ ﺍﻟﺘﺂﻛﻞ ﻭ ﺑـﺬﻟﻚ‬ ‫ﺗﺒﲎ ﻧﻈﺮﻳﺎﺕ ﻣﻨﻊ ﺍﻟﺘﺂﻛﻞ ﻋﻠﻰ ﺇﺣﺪﺍﺙ ﺧﻠﻞ ﰲ ﺃﺣﺪ ﺍﻟﺸﺮﻭﻁ ﺍﻟﺴﺎﺑﻘﺔ ﺑﻐﺮﺽ ﻣﻨﻊ ﺣـﺪﻭﺙ‬ ‫ﺍﻟﺘﺂﻛﻞ ﻛﻠﻴﺔ ‪.‬‬ ‫! ‪: )*+ :‬‬

‫ﻋﻨﺪ ﻏﻤﺲ ﻗﻀﻴﺒﲔ ﻣﻦ ﺍﳌﺎﻏﻨﺴﻴﻮﻡ ﻭ ﺍﻟﺼﻠﺐ ﰲ ﻭﺳﻂ ﻣﻮﺻﻞ ﻟﻠﻜﻬﺮﺑﺎﺀ ﻭ ﻋﻨﺪ ﺗﻮﺻـﻴﻞ ﺍﻟﻘـﻀﻴﺒﲔ‬ ‫ﺧﺎﺭﺟﻴﹰﺎ ﺑﺴﻠﻚ ﻳﺼﺒﺢ ﻗﻀﻴﺐ ﺍﳌﺎﻏﻨﺴﻴﻮﻡ ﺁﻧﻮﺩ ﺑﻴﻨﻤﺎ ﻗﻀﻴﺐ ﺍﻟﺼﻠﺐ ﻳﺼﺒﺢ ﻛﺎﺛﻮﺩ‪ .‬ﺣﻴـﺚ ﻳﻨـﺴﺎﺏ‬ ‫ﺇﻟﻜﺘﺮﻭﻥ ‪ -e‬ﺳﺎﻟﺐ ﺍﻟﺸﺤﻨﺔ ﺧﻼﻝ ﺳﻠﻚ ﺍﻟﺘﻮﺻﻴﻞ ﻣﻦ ﻗﻀﻴﺐ ﺍﳌﺎﻏﻨﺴﻴﻮﻡ ﺇﱃ ﻗـﻀﻴﺐ ﺍﻟـﺼﻠﺐ ﻭ‬ ‫ﻟﻼﺣﺘﻔﺎﻅ ﲝﺎﻟﺔ ﺍﻟﺘﻮﺍﺯﻥ ﻳﻨﺴﺎﺏ ﺃﻳﻮﻥ ﻣﻮﺟﺐ ﺍﻟﺸﺤﻨﺔ ‪ +Mg‬ﰲ ﺍﻟﻮﺳﻂ ﺍﻹﻟﻜﺘﺮﻭﻟﻴﱴ ) ﻫـﻮ ﺍﻟـﺬﻱ‬ ‫ﻳﺴﻤﺢ ﲟﺮﻭﺭ ﺍﻟﺘﻴﺎﺭ ﺧﻼﻟﻪ ﻣﻦ ﺍﳌﺼﻌﺪ ﺇﱃ ﺍﳌﻬﺒﻂ ﻭ ﻳﻜﻮﻥ ﺗﺮﺑﺔ ﺃﻭ ﻣﺎﺀ( ‪.‬ﻣﻦ ﻗﻀﻴﺐ ﺍﳌﺎﻏﻨﺴﻴﻮﻡ ﻣﺘﺠـﻪ‬ ‫ﺇﱃ ﻗﻀﻴﺐ ﺍﻟﺼﻠﺐ ﻭ ﻫﻜﺬﺍ ﳛﺪﺙ ﺗﺂﻛﻞ ﰲ ﻗﻀﻴﺐ ﺍﳌﺎﻏﻨﺴﻴﻮﻡ ﻭ ﻻ ﳛﺪﺙ ﺗﺂﻛﻞ ﰲ ﻗﻀﻴﺐ ﺍﻟﺼﻠﺐ‬ ‫‪.‬‬ ‫‪١٦٠‬‬


‫‪e‬‬

‫‪-‬‬

‫ﺁﻨﻭﺩ‬

‫ﻜﺎﺜﻭﺩ‬

‫ﻤﺎﻏﻨﺴﻴﻭﻡ‬

‫ﺍﻝﻜﺘﺭﻭﻝﻴﺕ‬ ‫‪Mg‬‬

‫ﺤﺩﻴﺩ‬

‫‪+‬‬

‫‘‪@ @âìîäËbßë@†í†y@Ý×dm@òîÜ@QMX@ÝØ‬‬ ‫‪* *01 234 / !. $- 3-8‬‬

‫‪) :ï;@çë@æ†È½a@—¥@ÝßaìÇ‬ﻃﺒﻴﻌﺔ ﺍﳌﻌﺪﻥ ﻭﻣﻮﻗﻌﻪ ﰲ ﺍﻟﺴﻠﺴﻠﺔ ﺍﻟﻜﻬﺮﻭﻛﻴﻤﻴﺎﺋﻴﺔ ‪ -‬ﺗﺸﻄﻴﺐ ﺍﻟﺴﻄﺢ ‪-‬‬ ‫ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﳌﻌﺪﻥ(‬ ‫‪) :ïç@ë@ÞìÜa@µg@ÉuŠm@ÝßaìÇ‬ﺩﺭﺟﺔ ﺗﺮﻛﻴﺰ ﺍﶈﻠﻮﻝ ‪ -‬ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﶈﻠﻮﻝ ‪ -‬ﺍﺧﺘﻼﻑ ﺍﻟﺘﻬﻮﻳﺔ(‪.‬‬ ‫‪CORROSION TYPES &789 6- 4-8‬‬

‫‪@ @@@âbÈÛa@Ý×fnÛa@@QMTMX‬‬ ‫ﻭ ﻫﻮ ﻣﺎ ﻳﻄﻠﻖ ﻋﻠﻴﻪ ﺍﻟﺘﺂﻛﻞ ﺍﳌﻨﺘﻈﻢ ﻭ ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ ﺛﺎﺑﺖ ﻋﻠـﻰ ﺍﻷﺳـﻄﺢ ﺍﻟﺪﺍﺧﻠﻴـﺔ ﻭ ﺍﳋﺎﺭﺟﻴـﺔ‬ ‫ﻟﻠﻤﻌﺪﺍﺕ ﺑﺄﻧﻮﺍﻋﻬﺎ ﺳﻮﺍﺀ ﻛﺎﻧﺖ ﺧﻄﻮﻁ ﺃﻭ ﺃﻭﻋﻴﺔ ﺿﻐﻂ ﺃﻭ ﻣﻮﺍﺳﲑ ﺃﻭ ﻏﲑﻫﺎ‪ .‬ﻭ ﻳﻘﺎﺱ ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ‬ ‫ﺍﳌﺄﺧﻮﺫ ﺑﺪﻻﻟﺔ ﻧﻘﺼﺎﻥ ﺍﻟﺴﻤﻚ ﺑﺎﳌﻌﺪﻥ ﻋﻦ ﺍﻟﺴﻤﻚ ﺍﻷﺻﻠﻲ ﻟﻠﻤﻌﺪﻥ‪ .‬ﻭ ﲟﻌﺮﻓﺔ ﺳﺎﻋﺎﺕ ﺍﻟﺘﺸﻐﻴﻞ ﳝﻜﻦ‬ ‫ﻗﻴﺎﺱ ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ ﻛﻞ ﻓﺘﺮﺓ ﺯﻣﻨﻴﺔ ﻣﻌﻴﻨﺔ ﻭ ﻣﻌﺎﻳﺮ‪‬ﺎ ﲟﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ ﺍﻟﺴﻨﻮﻯ ﳝﻜﻦ ﻣﻌﺮﻓﺔ ﺍﳊﺎﻟﺔ ﺍﻟﻌﺎﻣـﺔ‬ ‫ﻟﻠﻤﻌﺪﺓ‪ .‬ﻭ ﳛﺴﺐ ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ ﰱ ﻫﺬﻩ ﺍﳊﺎﻟﺔ ﺑﺎﳌﻌﺎﺩﻟﺔ ﺍﻵﺗﻴﺔ ‪:‬‬ ‫‪٧٩٠٠‬‬ ‫ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ = )ﺍﻟﺴﻤﻚ ﺍﻷﺻﻠﻲ ‪ -‬ﺍﻟﺴﻤﻚ ﺍﳊﺎﱄ( × ــــــــــ‬ ‫ﻓﺮﻕ ﻋﺪﺩ ﺳﺎﻋﺎﺕ ﺍﻟﺘﺸﻐﻴﻞ‬ ‫‪١٦١‬‬

‫ﻣﻢ ‪ /‬ﺳﻨﺔ‬


‫ﻣﺜﺎﻝ ‪ :‬ﺍﳌﻄﻠﻮﺏ ﲢﺪﻳﺪ ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ ﳌﺎﺳﻮﺭﺓ ﻛﺎﻥ ﺑﻴﺎ‪‬ﺎ ﻛﺎﻟﺘﺎﱄ ‪:‬‬ ‫ﺍﻟﺴﻤﻚ ﺍﻟﺴﺎﺑﻖ ‪ ١١‬ﻣﻢ ‪ -‬ﻋﺪﺩ ﺳﺎﻋﺎﺕ ﺍﻟﺘﺸﻐﻴﻞ = ‪ ٧٣٢٠٠‬ﺳﺎﻋﺔ‬ ‫ﺍﻟﺴﻤﻚ ﺍﳊﺎﱄ ‪ ٨‬ﻣﻢ ‪ -‬ﻋﺪﺩ ﺳﺎﻋﺎﺕ ﺍﻟﺘﺸﻐﻴﻞ = ‪ ٩٧١٠٠‬ﺳﺎﻋﺔ‬ ‫‪٧٩٠٠‬‬ ‫ـــــــــــ = ‪ ٠,٩٩١‬ﻣﻢ ‪ /‬ﺳﻨﺔ‬ ‫ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ = ) ‪× ( ٨ - ١١‬‬ ‫‪٧٣٢٠٠ - ٩٧١٠٠‬‬ ‫ﻭ ﻫﻨﺎﻙ ﺑﻌﺾ ﺍﳌﻌﺪﻻﺕ ﺣﻮﻝ ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ ﺍﻟﻘﻴﺎﺳﻲ ﳌﻮﺍﺳﲑ ﺍﳋﻄﻮﻁ ‪:‬‬ ‫ﺇﺫﺍ ﻛﺎﻥ ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ ﺃﻗﻞ ﻣﻦ ‪ ٠,٠٥‬ﻣﻢ ‪ /‬ﺳﻨﺔ ﻛﺎﻧﺖ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﻟﻠﺘﺂﻛﻞ ﳑﺘﺎﺯﺓ ‪.‬‬ ‫ﺇﺫﺍ ﻛﺎﻥ ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ ﻳﺘﺮﺍﻭﺡ ﺑﲔ ‪ ٠,٠٥‬ﻣﻢ ‪ /‬ﺳﻨﺔ ﻭ ‪ ٠,٥‬ﻣﻢ ‪ /‬ﺳﻨﺔ ﻛﺎﻧﺖ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﻟﻠﺘﺂﻛﻞ‬ ‫ﺟﻴﺪﺓ ‪.‬‬ ‫ﺇﺫﺍ ﻛﺎﻥ ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ ﻳﺘﺮﺍﻭﺡ ﺑﲔ ‪ ٠,٥‬ﻣﻢ ‪ /‬ﺳﻨﺔ ﻭ ‪ ١,٥‬ﻣﻢ ‪ /‬ﺳﻨﺔ ﻛﺎﻧﺖ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﻟﻠﺘﺂﻛـﻞ‬ ‫ﺿﻌﻴﻔﺔ ‪.‬‬ ‫‪@ @Z@éiby@òîÐî×@ë@aìàÜÛ@ïÔjn½a@ŠàÈÛa‬‬ ‫ﻫﻮ ﻋﺪﺩ ﺳﺎﻋﺎﺕ ﺍﻟﺘﺸﻐﻴﻞ ﺍﻟﻼﺯﻡ ﻗﺒﻞ ﺍﻟﻮﺻﻮﻝ ﺑﺎﻟﺴﻤﻚ ﺍﳊﺎﱄ ﺇﱃ ﺃﻗﻞ ﲰﻚ ﻣﺴﻤﻮﺡ ﺑﻪ ﻟﻠﻤﺎﺳﻮﺭﺓ ‪.‬‬ ‫ﲰﻚ ﺍﳌﺎﺳﻮﺭﺓ – ﺍﻗﻞ ﲰﻚ ﻣﺴﻤﻮﺡ‬ ‫ﺍﻟﻌﻤﺮ ﺍﳌﺘﺒﻘﻲ ﻟﻠﻤﺎﺳﻮﺭﺓ = ــــــــــــــــ‬ ‫ﻣﻌﺪﻝ ﺍﻟﺘﺂﻛﻞ‬

‫ﺳﻨﺔ‬

‫ﻣﺜﺎﻝ ‪ :‬ﻣﺎﺳﻮﺭﺓ ﲰﻜﻬﺎ ﺍﳊﺎﱄ ‪ ٧‬ﻣﻢ ﻭ ﺃﻗﻞ ﲰﻚ ﻣﺴﻤﻮﺡ ﺑﻪ ‪ ٥‬ﻣﻢ ﻭ ﻣﻌﺪﻝ ﺗﺂﻛﻠﻬﺎ ﺍﻟـﺴﻨﻮﻱ ‪١,٤٢‬‬ ‫ﻣﻢ ‪ /‬ﺳﻨﺔ ‪ -‬ﻣﻄﻠﻮﺏ ﺣﺴﺎﺏ ﺍﻟﻌﻤﺮ ﺍﳌﺘﺒﻘﻲ ﳍﺎ ‪.‬‬ ‫‪٥-٧‬‬ ‫ـــــــ‬ ‫ﺍﻟﻌﻤﺮ ﺍﳌﺘﺒﻘﻲ ﻟﻠﻤﺎﺳﻮﺭﺓ =‬ ‫‪١,٤٢‬‬

‫= ‪ ١,٤١‬ﺳﻨﻪ‬

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‫‪@ @@@óãbÐÜ¦a@Ý×fnÛa@@RMTMX‬‬ ‫ﳛﺪﺙ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ﻋﻨﺪ ﺗﻼﻣﺲ ﺃﻭ ﺍﺗﺼﺎﻝ ﻣﻌﺪﻧﲔ ﳐﺘﻠﻔﲔ ﰲ ﺍﳉﻬﺪ ﺍﻟﻜﻬـﺮﰊ ﺃﻱ ﻳـﺸﻜﻞ‬ ‫ﺃﺣﺪ ﺍﳌﻌﺪﻧﲔ ﻣﻨﻄﻘﺔ ﺁﻧﻮﺩ ﻭ ﺍﻵﺧﺮ ﻣﻨﻄﻘﺔ ﻛـﺎﺛﻮﺩ ﻭ ﳝﻜـﻦ ﻣﻌﺮﻓـﺔ ﺫﻟـﻚ ﺑﺪﺭﺍﺳـﺔ ﺍﻟﺴﻠـﺴﻠﺔ‬ ‫ﺍﻟﻜﻬﺮﻭﻛﻴﻤﻴﺎﺋﻴﺔ )‪ (GALVANIC SERIES‬ﺣﻴﺚ ﻳﺒﲔ ﺟﺪﻭﻝ )‪ (١- ٨‬ﺃﻥ ﺍﻟﻘﻄﺐ ﺍﻟﺬﻱ ﻳﻜﻮﻥ‬ ‫ﻣﻮﺟﺐ ﻳﻜﻮﻥ ﻛﺎﺛﻮﺩ ﻭ ﺍﻵﺧﺮ ﺍﻟﺴﺎﻟﺐ ﺁﻧﻮﺩ ‪.‬‬ ‫‪@ @@@@paì;vÐÛa@í@Ý×fnÛa@@SMTMX‬‬ ‫ﳛﺪﺙ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ﰲ ﺍﻟﻔﺠﻮﺍﺕ ﺍﻟﺼﻐﲑﺓ ﺍﳌﻮﺟﻮﺩﺓ ﺑﲔ ﻣﻌﺪﻧﲔ ﻣﺜـﻞ ﻓﺠـﻮﺍﺕ ﺍﳌـﺴﺎﻣﲑ‬ ‫ﺍﳌﻘﻠﻮﻇﺔ ﻭ ﺧﻼﻓﻪ ﻭ ﺍﻟﱵ ﻳﻜﻮﻥ ﺗﺮﻛﻴﺰ ﺍﻷﻛﺴﺠﲔ ﰲ ﺗﻠﻚ ﺍﻟﻔﺠﻮﺍﺕ ﳏﺪﻭﺩ )ﺁﻧﻮﺩ( ﺑﻴﻨﻤـﺎ ﺍﻟـﺴﻄﺢ‬ ‫ﺍﳋﺎﺭﺟﻲ ﻳﻜﻮﻥ )ﻛﺎﺛﻮﺩ( ﺑﻪ ﺗﺮﻛﻴﺰ ﻋﺎﱄ ﻣﻦ ﺍﻷﻛﺴﺠﲔ ﳑﺎ ﻳﺆﺩﻯ ﳊﺪﻭﺙ ﺗﺂﻛﻞ ﻟﺘﻠـﻚ ﺍﻟﻔﺠـﻮﺍﺕ‬ ‫)ﺍﻵﻧﻮﺩ( ‪.‬‬ ‫‪@ @Š;Ô;ä;Ûbi@Ý×fnÛa@@TMTMX‬‬ ‫ﺍﻟﺘﺂﻛﻞ ﺑﺎﻟﻨﻘﺮ ﻫﻮ ﻋﺒﺎﺭﺓ ﻋﻦ ﻫﺠﻮﻡ ﻣﻮﺿﻌﻲ ﺳﺮﻳﻊ ﻳﻨﺸﺄ ﻋﻦ ﺗﻜﻮﻳﻦ ﲡﻮﻳﻒ ﺩﺍﺧﻞ ﺍﳌﻌﺪﻥ ﺍﻟﻐﲑ ﻣﻌﺮﺽ‬ ‫ﻟﻠﺘﺂﻛﻞ ﳑﺎ ﻳﺆﺩﻯ ﺇﱃ ﻭﺻﻮﻝ ﺍﻟﺘﺨﺎﻧﺔ ﰲ ﺑﻌﺾ ﺍﳌﻨﺎﻃﻖ ﺇﱃ ﺍﻟﺼﻔﺮ ﻭ ﻳﺆﺩﻯ ﳊﺪﻭﺙ ﺍﻟﺜﻘﻮﺏ ﺍﻟﻌﺪﻳـﺪﺓ‬ ‫ﻧﺘﻴﺠﺔ ﺗﻌﺮﺽ ﺍﳌﻌﺪﻥ ﻷﻭﺳﺎﻁ ﺃﻛﺎﻟﺔ ﺷﺪﻳﺪﺓ ﻭ ﳛﺪﺙ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﺩﺍﺋﻤﹰﺎ ﰱ ﺃﻧﻮﺍﻉ ﻋﺪﻳﺪﺓ ﻣﻦ ﺍﻟﺴﺘﺎﻧﻠﺲ‬ ‫ﺳﺘﻴﻞ‪ .‬ﳛﺪﺙ ﺍﻟﺘﺂﻛﻞ ﺑﺎﻟﻨﻘﺮ ﻋﺎﺩﺓ ﰱ ﺍﳌﻌﺎﺩﻥ ﺍﻟﱵ ﺗﻈﻬﺮ ﻓﻴﻬﺎ ﻇﺎﻫﺮﺓ ﺍﳋﻤﻮﻝ ﺃﻭ ﺍﻟﱵ ﺗﻐﻄﻰ ﺑﻄﺒﻘﺔ ﻣـﻦ‬ ‫ﺍﻷﻛﺴﻴﺪ ﺣﻴﺚ ﳛﺪﺙ ‪‬ﺎ ﺧﺪﺵ ﻳﻨﺘﺞ ﻋﻨﻪ ﻣﺴﺎﺣﺔ ﺁﻧﻮﺩﻳﺔ ﺻﻐﲑﺓ ﻭ ﺗﻜﻮﻥ ﺍﳌﺴﺎﺣﺔ ﺍﻟﻜﺎﺛﻮﺩﻳﺔ ﻛﺒﲑﺓ ﻭ‬ ‫ﻳﻜﻮﻥ ﺗﻴﺎﺭ ﺍﻟﺘﺂﻛﻞ ﻋﺎﱄ ﻳﺆﺩﻯ ﻟﺘﺂﻛﻞ ﺍﻟﺴﻄﺢ ‪.‬‬ ‫‪@ @ð‰bînüa@Ý×fnÛa@@UMTMX‬‬ ‫ﳛﺪﺙ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ﻓﻘﻂ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﺴﺒﺎﺋﻚ ﺍﻟﱵ ﺗﺘﻜﻮﻥ ﻣﻦ ﻣﻌﺪﻧﲔ ﺃﻭ ﺃﻛﺜﺮ ﻭ ﻳﺒﺪﺃ ﺍﻟﺘﺂﻛـﻞ‬ ‫ﺑﺴﺒﺐ ﺍﺧﺘﻼﻑ ﻣﻮﺿﻌﻲ ﰲ ﺍﻟﺘﺮﻛﻴﺐ ﻭ ﻧﺘﻴﺠﺔ ﻟﺬﻟﻚ ﻳﺒﻘﻰ ﺍﳌﻌﺪﻥ ﺍﻷﻛﺜﺮ ﻛﺎﺛﻮﺩﻳﺔ ﺑﻴﻨﻤﺎ ﻳﺘﺂﻛﻞ ﺍﳌﻌﺪﻥ‬ ‫ﺍﻷﻛﺜﺮ ﺍﻧﻮﺩﻳﺔ‪ .‬ﻭ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺴﺒﻴﻜﺔ ﺗﻌﺘﻤﺪ ﻋﻠﻰ ﺗﺮﻛﻴﺒﻬﺎ ﻭ ﺗﺰﺩﺍﺩ ﺍﳌﻘﺎﻭﻣﺔ ﻟﻠﺘﺂﻛﻞ ﺑﺰﻳﺎﺩﺓ ﺗﺮﻛﻴﺰ ﺍﳌﻌـﺪﻥ‬ ‫ﺍﻷﻛﺜﺮ ﻛﺎﺛﻮﺩﻳﺔ ﰲ ﺍﻟﺴﺒﻴﻜﺔ ‪.‬‬

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‫‪@ @@@óØîãbØîß@ÝßbÈi@kyb–½a@Ý×fnÛa@@VMTMX‬‬ ‫ﻭ ﳛﺪﺙ ﻧﺘﻴﺠﺔ ﻗﻮﻯ ﺍﻟﻘﺺ ﻭ ﺍﻻﺣﺘﻜﺎﻙ ﺑﲔ ﺍﻟﺴﺎﺋﻞ ﻭ ﺍﳌﻌﺪﻥ ﻭ ﻳﺮﺟﻊ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣـﻦ ﺍﻟﺘﺂﻛـﻞ ﺇﱃ‬ ‫ﺍﻟﺘﺂﻛﻞ ﺍﻟﻨﺎﺗﺞ ﻋﻦ ﺗﺄﺛﲑ ﺍﻟﻔﻌﻞ ﺍﳌﻴﻜﺎﻧﻴﻜﻲ ﻟﻠﺴﺎﺋﻞ ﻋﻠﻰ ﺍﳌﻌﺪﻥ ‪.‬‬ ‫‪@ @@@@õb½a@|Đ@o¤@Ý×fnÛa@@WMTMX‬‬ ‫ﳛﺪﺙ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ﲢﺖ ﻣﺴﺘﻮﻯ ﺍﳌﺎﺀ ﻣﺒﺎﺷﺮﺓ ﻭ ﺫﻟﻚ ﻟﻠﻤﻌﺎﺩﻥ ﺍﳌﻐﻤﻮﺳﺔ ﰱ ﺍﳌﺎﺀ ﺃﻭ ﺍﻟﺘﺮﺑﺔ ﻭ‬ ‫ﻫﺬﺍ ﻧﺎﺗﺞ ﻋﻦ ﺍﺧﺘﻼﻑ ﺗﺮﻛﻴﺰ ﺍﻷﻛﺴﺠﲔ ﻋﻠﻰ ﺍﻟﺴﻄﺢ ﻣﻨﻪ ﻟﺪﺍﺧﻞ ﺍﳌﺎﺀ ) ﺣﻴﺚ ﺍﳌﻨﺎﻃﻖ ﺍﳌﻐﻤﻮﺭﺓ ﺑﺎﳌﺎﺀ‬ ‫ﺗﻌﺘﱪ ﺁﻧﻮﺩ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﻤﻨﺎﻃﻖ ﺫﺍﺕ ﺍﻟﺘﺮﻛﻴﺰ ﺍﻟﻌﺎﱃ ﻣﻦ ﺍﻷﻛﺴﺠﲔ ( ﻭ ﳛﺪﺙ ﺍﻟﺘﺂﻛﻞ ﰱ ﺍﳌﻨﺎﻃﻖ ﺍﳌﻐﻤﻮﺭﺓ‬ ‫)ﺍﻵﻧﻮﺩ(‪.‬‬ ‫‪@ @@@@k;aëŠ;Ûa@åÇ@wmbäÛa@Ý×fnÛa@@XMTMX‬‬ ‫ﳛﺪﺙ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ﻧﺘﻴﺠﺔ ﻭﺟﻮﺩ ﺭﻭﺍﺳﺐ ﻋﻠﻰ ﺃﺟﺰﺍﺀ ﺍﳌﻌﺪﻥ ﻭ ﺍﻟﱵ ﲢﺠﺐ ﺟﺰﺀ ﻣﻦ ﺍﳌﻌﺪﻥ‬ ‫ﻋﻦ ﺍﻷﻛﺴﺠﲔ ﳑﺎ ﻳﺆﺩﻯ ﺇﱃ ﺗﻜﻮﻳﻦ ﺧﻠﻴﺔ ﺍﻟﺘﺮﻛﻴﺰ ﺑﺎﻷﻛﺴﺠﲔ ﻭ ﳛﺪﺙ ﺍﻟﺘﺂﻛﻞ ﰲ ﺍﻷﻣﺎﻛﻦ ﺍﻟﱵ ﻳﻮﺟﺪ‬ ‫ﻋﻠﻴﻬﺎ ﺍﻟﺮﻭﺍﺳﺐ )ﺫﺍﺕ ﺍﻟﺘﺮﻛﻴﺰ ﺍﻷﻛﺴﺠﻴﲏ ﺍﳌﻨﺨﻔﺾ( ‪.‬‬ ‫‪@ @@@@pbjîj§a@…ë†y@í@Ý×fnÛa@Y@MTMX‬‬ ‫ﳛﺪﺙ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ﻟﻠﺼﻠﺐ ﺍﻷﺳﺘﻴﲎ ‪ ٨/١٨‬ﺍﶈﺘﻮﻯ ﻋﻠﻰ ﻧﺴﺒﺔ ﻛﺮﺑﻮﻥ ﺑـﲔ ) ‪- ٠,٠٨‬‬ ‫‪ % ٠,١‬ﰱ ﺩﺭﺟﺎﺕ ﺍﳊﺮﺍﺭﺓ ﻣﺎ ﺑﲔ ‪ ٨٠٠ - ٤٠٠‬ﻡ‪ o‬ﺃﻭ ﺇﺫﺍ ﺑﺮﺩ ﺗﱪﻳﺪﹰﺍ ﺑﻄﻴﺌﹰﺎ ﰲ ﻧﻔﺲ ﺍﳌﺪﻯ ﻣـﻦ‬ ‫ﺩﺭﺟﺎﺕ ﺍﳊﺮﺍﺭﺓ (‪ .‬ﻭ ﻣﻦ ﺍﻷﻭﺳﺎﻁ ﺍﻷﻛﺎﻟﺔ ﺍﳌﺴﺒﺒﺔ ﳍﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ) ﳏﺎﻟﻴﻞ ﺍﻷﲪﺎﺽ ‪ -‬ﳏﺎﻟﻴﻞ‬ ‫ﺍﻟﻜﻠﻮﺭﻳﺪﺍﺕ ﺍﳌﺘﻌﺎﺩﻟﺔ ﻣﺜﻞ ﻣﺎﺀ ﺍﻟﺒﺤﺮ(‪ .‬ﻛﻤﺎ ﺃﻥ ﻃﺮﻳﻘﺔ ﺍﻟﻠﺤﺎﻡ ﳍﺎ ﺗﺄﺛﲑ ﺃﻳـﻀﹰﺎ ﺧـﺼﻮﺻﹰﺎ ﺍﻟﻘـﻮﺱ‬ ‫ﺍﻟﻜﻬﺮﺑﺎﺋﻰ )ﺣﺮﺍﺭﺓ ﻋﺎﻟﻴﺔ ‪ -‬ﺗﱪﻳﺪ ﺑﻄﺊ( ﳑﺎ ﳚﻌﻞ ﺍﻟﺼﻠﺐ ﺣﺴﺎﺱ ﳍﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ‪.‬‬ ‫‪@ @ ô…bèu⁄a@óŠ’nÛa@Ý×fnÛa@QP@TMX‬‬ ‫ﺍﻟﺘﺸﺮﺥ ﺍﻹﺟﻬﺎﺩﻯ ﺍﻟﺘﺂﻛﻠﻰ ﻳﻄﻠﻖ ﻋﻠﻰ ﺍﻟﺘﺄﺛﲑ ﺍﳌﺸﺘﺮﻙ ﺑﲔ ﺍﺟﻬﺎﺩﺍﺕ ﺍﻟﺸﺪ ﻭ ﺍﻟﻮﺳﻂ ﺍﻷﻛﺎﻝ ﻋﻠـﻰ‬ ‫ﺍﳌﻌﺪﻥ ﻭ ﻫﻲ ﺍﺟﻬﺎﺩﺍﺕ ﳝﻜﻦ ﺃﻥ ﺗﻜﻮﻥ ﻣﻄﺒﻘﺔ ﻋﻠﻰ ﺍﳌﻌﺪﻥ ﺃﻭ ﺍﺟﻬﺎﺩﺍﺕ ﻣﺘﺨﻠﻔﺔ ﺩﺍﺧﻞ ﺍﳌﻌﺪﻥ ﻭ ﺍﻟﱵ‬ ‫ﺗﻨﺸﺄ ﻧﺘﻴﺠﺔ ﻇﺮﻭﻑ ﻋﺪﻳﺪﺓ ﻣﻨﻬﺎ ) ﺍﻟﺘﺼﻤﻴﻢ ﺍﻟﻐﲑ ﺟﻴﺪ ‪ -‬ﺍﻟﺘﺸﻐﻴﻞ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ‪ -‬ﻋﻤﻠﻴﺎﺕ ﺍﻟﻠﺤﺎﻡ(‪.‬‬

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@ @òîöbîàî×ëŠèØÛa@òÜÜÛaQ@M@X@Þë†u Š–äÈÛa@Œß‰

óbîÔÛa@kĐÔÛa@†èu

Š–äÈÛa

Li

٣,٠١-

âìîrîÜÛa

K

٢,٩٢-

âìîbmìjÛa

Ca

٢,٨٤-

âìîÛbØÛa

Na

٢,٧١-

âìí…ì–Ûa

Mg

٢,٣٨-

âìîäËbß

Al

١,٦٦-

âìîäßìÛc

Zn

٠,٧٦-

´•‰b@M@Ùã‹

Cr

٠,٧١-

âëŠ×

Fe

٠,٤٤-

†í†y

Cd

٠,٤-

âìîß…b×

Ni

٠,٢٣-

ÝØîã

Sn

٠,١٤-

Ší†–Ó

Pb

٠,١٣-

˜b•‰

H

‫ﺻﻔﺮ‬

úë‰†îç

Cu

٠,٣٤+

÷b−

Ag

٠,٨+

òšÏ

Pd

٠,٨٣+

âìí…ýi

Hg

٠,٨٥+

Õjö‹

Pt

١,٢+

´mýi

Au

١,٤٢+

kç‡

١٦٥


‫‪& -* ";- &84 :-‬‬

‫ﻳﺘﻢ ﺩﻓﻦ ﺧﻄﻮﻁ ﺍﻟﺼﻠﺐ ﻋﻠﻰ ﺃﻋﻤﺎﻕ ﻗﺪ ﺗﺼﻞ ﺇﱃ ‪ ٢‬ﻣﺘﺮ ﺣﻴﺚ ﻳﺮﺗﻔﻊ ﻣﺴﺘﻮﻯ ﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ ﻟﻴـﺼﺒﺢ‬ ‫ﺍﻟﺮﺩﻡ ﻭﺳﻂ " ﺍﻟﻜﺘﺮﻭﻟﻴﱴ " ﺟﻴﺪ ﺍﻟﺘﻮﺻﻴﻞ ﻟﻠﻜﻬﺮﺑﻴﺔ ﻭ ﺗﺘﻜﻮﻥ ﺧﻠﻴﺔ ﺍﻟﺘﺂﻛﻞ ﻋﻨﺪ ﺗﻌﺮﺽ ﺧﻂ ﺍﻟﺼﻠﺐ‬ ‫ﺇﱃ ﺍﻟﻈﺮﻭﻑ ﺍﻟﺘﺎﻟﻴﺔ ‪-:‬‬ ‫<‪: ?8@ =4 > -$ -$ 6-‬‬

‫ﻋﻨﺪ ﺍﺗﺼﺎﻝ ﺧﻂ ﺍﻟﺼﻠﺐ ﲟﻌﺪﻥ ﻳﺴﺒﻘﻪ ﰱ ﺍﻟﺴﻠﺴﻠﺔ ﺍﻟﻜﻬﺮﻭﻛﻴﻤﻴﺎﺋﻴﺔ ) ﳓﺎﺱ ( ﻓﺈﻥ ﺧـﻂ ﺍﻟـﺼﻠﺐ‬ ‫ﻳﺼﺒﺢ ﺁﻧﻮﺩ ﺑﻴﻨﻤﺎ ﻭﺻﻠﺔ ﺍﻟﻨﺤﺎﺱ ﺗﺼﺒﺢ ﻛﺎﺛﻮﺩ ‪.‬‬

‫ﺨﻁ ﺍﻝﺼﻠﺏ‬

‫ﻤﺎﺴﻭﺭﺓ ﻤﻥ ﺍﻝﻨﺤﺎﺱ‬

‫‘‪@ @kÜ–Ûa@ë@÷bzäÛa@í@Ý×fm@òîÜ@RMX@ÝØ‬‬

‫ﻗﺪ ﲢﺪﺙ ﺧﻠﻴﺔ ﺍﻟﺘﺂﻛﻞ ﺑﲔ ﻣﺎﺳﻮﺭﺓ ﺍﻟﺼﻠﺐ ﺍﳉﺪﻳﺪﺓ ﺍﳌﺘﺼﻠﺔ ﻣﻊ ﺧﻂ ﻋﺎﻣﻞ ﻗﺪﱘ ﺃﺛﺮ ﻋﻤﻠﻴﺔ ﺇﺣﻼﻝ ﺃﻭ‬ ‫ﺇﺻﻼﺡ ﻓﺘﻜﻮﻥ ﺍﳌﺎﺳﻮﺭﺓ ﺍﳉﺪﻳﺪﺓ " ﺁﻧﻮﺩ " ﺑﻴﻨﻤﺎ ﺑﺎﻗﻲ ﺍﳋﻂ " ﻛﺎﺛﻮﺩ " ‪.‬‬

‫‪Fe‬‬

‫ﺨﻁ ﺍﻝﺼﻠﺏ ﺍﻝﻘﺩﻴﻡ‬

‫‪++‬‬

‫‪Fe‬‬

‫ﻤﺎﺴﻭﺭﺓ ﺤﺩﻴﺜﺔ‬

‫‪++‬‬

‫ﺨﻁ ﺍﻝﺼﻠﺏ ﺍﻝﻘﺩﻴﻡ‬

‫‘‪@ @kî×Ûa@òrí†y@kÜ–Ûa@aìß@óÏ@Ý×fm@òîÜ@SMX@ÝØ‬‬

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‫ﻭ ﲢﺪﺙ ﺧﻠﻴﺔ ﺍﻟﺘﺂﻛﻞ ﰲ ﻣﻨﺎﻃﻖ ﺭﺀﻭﺱ ﺍﻟﻠﺤﺎﻣﺎﻥ ﻧﺘﻴﺠﺔ ﺍﺧﺘﻼﻑ ﺍﳌﻨﻄﻘﺔ ﺍﳌﺘﺄﺛﺮﺓ ﺑﺎﻟﻠﺤﺎﻡ ﻣﻴﺘﺎﻟﻮﺭﺟﻴـﹰﺎ‬ ‫ﻋﻦ ﻣﻨﺎﻃﻖ ﺍﳌﺎﺳﻮﺭﺓ ﺍﻷﺧﺮﻯ ﻓﺘﺼﺒﺢ ﺗﻠﻚ ﺍﳌﻨﻄﻘﺔ " ﺁﻧﻮﺩﹰﺍ " ﺑﻴﻨﻤﺎ ﺑﺎﻗﻲ ﺟﺴﻢ ﺍﳌﺎﺳﻮﺭﺓ " ﻛﺎﺛﻮﺩﹰﺍ " ‪.‬‬

‫‪Fe‬‬

‫‪++‬‬

‫‪++‬‬

‫‪Fe‬‬

‫‘‪@ @pbßbzÜÛa@÷ëõ‰@Õbäß@óÏ@Ý×fm@òîÜ@@TMX@ÝØ‬‬ ‫<‪: A -$ > -$ 6-‬‬

‫ﺟﺰﺀ ﺧﻂ ﺍﻟﺼﻠﺐ ﺍﳌﺪﻓﻮﻥ ﰱ ﺍﻟﺮﺩﻡ ﺍﳌﺸﺒﻊ ﺑﺄﲪﺎﺽ ﻣﺘﺴﺮﺑﺔ ﻣﻦ ﻭﻋﺎﺀ ﺗﺼﺒﺢ ﺁﻧﻮﺩﹰﺍ ﺑﻴﻨﻤﺎ ﺑﺎﻗﻲ ﺍﳋـﻂ‬ ‫ﻳﺼﺒﺢ ﻛﺎﺛﻮﺩﹰﺍ ‪.‬‬

‫ﺧﺰﺍﻥ ﺃﲪﺎﺽ‬

‫‪Fe‬‬

‫‪++‬‬

‫‪Ý×fm‬ﺍﻝﻤﺸﺒﻊ ﺒﺎﻷﺤﻤﺎﺽ‬ ‫ﺍﻝﻭﺴﻁ‬ ‫ﺨﻠﻴﺔ‬ ‫@‪@ @āb»þbi@Éj’½a@ÁìÛa@óÏ‬‬ ‫ﺘﺂﻜل‪@@U‬ﻓﻰ‪@òîÜ‬‬ ‫‘‪MX@ÝØ‬‬

‫ﺍﺧﺘﻼﻑ ﻧﺴﺒﺔ ﺗﺮﻛﻴﺰ ﺍﻷﻣﻼﺡ ﰱ ﻣﻮﺍﺩ ﺍﻟﺮﺩﻡ ﻳﺆﺩﻯ ﺇﱃ ﺗﻜﻮﻳﻦ ﺧﻠﻴﺔ ﺍﻟﺘﺂﻛﻞ ‪ .‬ﻓﻨﺠﺪ ﺃﻥ ﺟﺰﺋﻴﺔ ﺍﳋـﻂ‬ ‫ﺍﳌﺎﺭ ﰱ ﻣﻨﻄﻘﺔ ﺫﺍﺕ ﺗﺮﻛﻴﺰ ﻣﻠﺤﻲ ﻣﻨﺨﻔﺾ ﺗﻜﻮﻥ " ﺁﻧﻮﺩﹰﺍ " ﺑﻴﻨﻤﺎ ﺟﺰﺋﻴﺔ ﺍﳋﻂ ﺍﳌﺎﺭ ﰲ ﺍﳌﻨﻄﻘـﺔ ﺫﺍﺕ‬ ‫ﺗﺮﻛﻴﺰ ﻣﻠﺤﻲ ﻋﺎﱄ ﺗﻜﻮﻥ " ﻛﺎﺛﻮﺩﹰﺍ "‪٠‬‬

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‫ﻣﻨﻄﻘﺔ ﺗﺮﻛﻴﺰ ﺃﻣﻼﺡ‬

‫‪Fe‬‬

‫‪++‬‬

‫ﻣﻨﻄﻘﺔ ﺗﺮﻛﻴﺰ ﺃﻣﻼﺡ ﻋﺎﻟﻴﺔ‬

‫@‪@Áë@óÏ‬ﻤﺨﺘﻠﻑ ﺍﻝﺘﺭﻜﻴﺯ‬ ‫ﻭﺴﻁ ﻤﻠﺤﻰ‬ ‫ﺨﻠﻴﺔ@@ﺘﺂﻜل‬ ‫‪@ @Œî×Ûa@ÑÜn«@ózÜß‬‬ ‫‪@òîÜ‬ﻓﻰ‪Ý×fm‬‬ ‫‘‪VMX@ÝØ‬‬

‫ﻧﺴﺒﺔ ﺍﶈﺘﻮﻯ ﺍﻷﻛﺴﻮﺟﻴﲎ ﰱ ﺭﺩﻡ ﺍﳋﻂ ‪ :‬ﺍﺧﺘﻼﻑ ﺩﺭﺟﺔ ﺍﻟﺘﻬﻮﻳﺔ ﰲ ﺭﺩﻡ ﺧﻄﻮﻁ ﺍﻟﺼﻠﺐ ﻳـﺆﺩﻯ ﺇﱃ‬ ‫ﺗﻜﻮﻳﻦ ﺧﻠﻴﺔ ﺍﻟﺘﺂﻛﻞ ‪ .‬ﻓﻨﺠﺪ ﺃﻥ ﺟﺰﻳﺔ ﺧﻂ ﺍﻟﺼﻠﺐ ﺍﳌﺮﺩﻭﻣﺔ ﰲ ﻣﻨﻄﻘﺔ ﺫﺍﺕ ﺗﺮﻛﻴﺰ ﺃﻛﺴﺠﲔ ﻣﻨﺨﻔﺾ‬ ‫ﺗﻜﻮﻥ " ﺁﻧﻮﺩﹰﺍ " ﺑﻴﻨﻤﺎ ﺍﳌﺮﺩﻭﻣﺔ ﰲ ﻣﻨﻄﻘﺔ ﺫﺍﺕ ﺗﺮﻛﻴﺰ ﺃﻛﺴﺠﲔ ﻋﺎﻟﻴﺔ ﺗﻜﻮﻥ " ﻛﺎﺛﻮﺩﹰﺍ " ‪.‬‬

‫ﺭﻣﺎﻝ‬

‫ﺗﺮﺑﺔ ﻃﻴﻨﻴﺔ‬ ‫‪Fe‬‬

‫‪++‬‬

‫‘‪@ @óäîuì×üa@Œî×Ûa@ÑÜn«@Áë@óÏ@Ý×fm@òîÜ@@WMX@ÝØ‬‬

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‫‪ :$ & EF CD 5-8‬‬

‫‪@ @Z@kbä½a@áîà–nÛa@‰bîna @NQ‬‬ ‫•‬

‫ﺍﻟﺒﺴﺎﻃﺔ ﰱ ﺍﻟﺘﺼﻤﻴﻢ ‪.‬‬

‫•‬

‫ﲡﻨﺐ ﺗﻜﻮﻳﻦ ﺍﳋﻼﻳﺎ ﺍﳉﻠﻔﺎﻧﻴﺔ ‪.‬‬

‫•‬

‫ﲡﻨﺐ ﺍﻟﺮﻃﻮﺑﺔ ‪.‬‬

‫‪@ @Z@æ†È½a@òîÇìã@Ýí†Èm NR‬‬ ‫•‬

‫ﺇﺯﺍﻟﺔ ﺍﻟﻌﻨﺎﺻﺮ ﺍﳌﻀﺎﺩﺓ ﺍﳌﺴﺒﺒﺔ ﻟﻠﺘﺂﻛﻞ ‪.‬‬

‫•‬

‫ﺇﺿﺎﻓﺔ ﺍﻟﻌﻨﺎﺻﺮ ﺍﶈﺴﻨﺔ ﳌﻘﺎﻭﻣﺔ ﺍﻟﺘﺂﻛﻞ ‪.‬‬

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‫ﺇﲤﺎﻡ ﺃﻋﻤﺎﻝ ﺍﳌﻌﺎﳉﺔ ﻹﺯﺍﻟﺔ ﺍﻻﺟﻬﺎﺩﺍﺕ ﺍﳌﺘﻮﺍﻓﺮﺓ ﺍﻟﱴ ﻧﺘﺠﺖ ﻋﻦ ﺃﻋﻤﺎﻝ ﺍﻟﻠﺤﺎﻡ ‪.‬‬

‫‪@ @Z@Ý×fnÛa@Áë@îÌm@ë@Ýí†Èm NS‬‬ ‫•‬

‫ﺇﺯﺍﻟﺔ ﺍﻷﻣﻼﺡ ﻋﻦ ﻃﺮﻳﻖ ﺃﻋﻤﺎﻝ ﺍﻟﺘﺄﻳﻦ ‪.‬‬

‫•‬

‫ﺇﺯﺍﻟﺔ ﺍﻷﲪﺎﺽ ﺑﺈﺿﺎﻓﺔ ﺍﳉﲑ ﻭ ﺍﳌﻮﺍﺩ ﺍﻟﻘﻠﻮﻳﺔ ‪.‬‬

‫•‬

‫ﺗﻘﻠﻴﻞ ﻧﺴﺒﺔ ﺗﻮﺍﺟﺪ ﺍﻷﻛﺴﺠﲔ ﺑﺈﺿﺎﻓﺔ ﻣﻮﺍﻧﻊ ﺍﻟﺘﺂﻛﻞ )ﻛﻠﻮﺭﻳﺪ ﺍﻟﺼﻮﺩﻳﻮﻡ ﻭ ﺍﻷﻣﻮﻧﻴـﺎ ﻭ ﻣﻮﺍﻧـﻊ‬ ‫ﺍﻟﺘﺂﻛﻞ ﻭ ﺍﳌﻮﺍﺩ ﺍﻟﻜﻴﻤﺎﻭﻳﺔ ﺍﳌﻘﺎﻭﻣﺔ ﻟﻌﻤﻠﻴﺔ ﺍﻟﺘﺂﻛﻞ( ‪.‬‬

‫‪@ @ZòîĐÌnÛa @NT‬‬ ‫ﻫﻰ ﻭﺳﻴﻠﺔ ﺍﻟﻐﺮﺽ ﻣﻨﻬﺎ ﺗﻜﻮﻳﻦ ﻏﺸﺎﺀ ﻣﺘﺼﻞ ﻣﻦ ﻣﺎﺩﺓ ﻋﺎﺯﻟﺔ ﻟﻠﻜﻬﺮﺑﺎﺀ ﻋﻠﻰ ﺳﻄﺢ ﺍﳌﻌﺪﻥ ﺍﳌﺮﺍﺩ ﲪﺎﻳﺘﻪ‬ ‫ﻋﻦ ﺍﻟﻮﺳﻂ ﺍﻻﻟﻜﺘﺮﻭﻟﻴﱴ ﺍﳌﻼﻣﺲ ﻟﻪ ﻭ ﻛﺬﻟﻚ ﺍﻋﺘﺮﺍﺽ ﺍﻟﺪﺍﺋﺮﺓ )ﺍﻵﻧﻮﺩﻳﺔ – ﺍﻟﻜﺎﺛﻮﺩﻳﺔ( ﻋﻦ ﻃﺮﻳـﻖ‬ ‫ﺫﻟﻚ ﺍﻟﻐﺸﺎﺀ ﺫﻭ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻜﻬﺮﺑﻴﺔ ﺍﻟﻌﺎﻟﻴﺔ ﻭ ﺑﺎﻟﺘﺎﱃ ﻳﻀﻤﺤﻞ ﺑﻞ ﻭ ﻳﻜﺎﺩ ﻳﺘﻼﺷﻰ ﺗﻴﺎﺭ ﺍﻟﺘﺂﻛﻞ‪ .‬ﻭ ﻣـﻦ‬ ‫ﺍﳌﻌﻠﻮﻡ ﺃﻥ ﺃﺳﺎﻟﻴﺐ ﺍﻟﺘﻐﻄﻴﺔ ﺍﳉﻴﺪﺓ ﻭ ﺍﳌﻨﺎﺳﺒﺔ ﻭ ﺍﻟﱴ ﺗﻜﻮﻥ ﻛﻔﺎﺀ‪‬ﺎ ﺃﻛﺜﺮ ﻣﻦ ‪ %٩٩‬ﻣﻦ ﺳﻄﺢ ﺍﳌﻨـﺸﺄ‬ ‫ﺍﳌﻌﺪﱏ ﲢﻤﻰ ﻫﺬﺍ ﺍﳌﻨﺸﺄ ﲤﺎﻣﹰﺎ ﻣﻦ ﺍﻟﺘﺂﻛﻞ ﺇﱃ ﺟﺎﻧﺐ ﻫﺬﺍ ﺇﺫﺍ ﻃﺒﻖ ﻧﻈﺎﻡ ﻟﻠﺤﻤﺎﻳﺔ ﺍﻟﻜﺎﺛﻮﺩﻳﺔ ﻟﻠﻤﻨـﺸﺂﺕ‬ ‫ﺑﺎﻟﺘﻐﻄﻴﺔ ﻓﺈﻧﻪ ﻳﻜﻮﻥ ﻧﻈﺎﻡ ﺑﺴﻴﻂ ﻧﺴﺒﻴﹰﺎ ﺣﻴﺚ ﺗﻜﻮﻥ ﺍﳌﺴﺎﺣﺎﺕ ﺍﳌﻜﺸﻮﻓﺔ ﺃﻭ ﺍﻟﻀﻌﻴﻔﺔ ﺍﻟﺘﻐﻄﻴﺔ ﻫﻰ ﻓﻘﻂ‬ ‫ﺍﳌﺮﺍﺩ ﲪﺎﻳﺘﻬﺎ ﺑﻮﺍﺳﻄﺔ ﺃﺳﺎﻟﻴﺐ ﺍﳊﻤﺎﻳﺔ ﺍﻟﻜﺎﺛﻮﺩﻳﺔ ‪ .‬ﻭ ﻧﻘﺺ ﺍﳌﻌﺮﻓﺔ ﻳﺆﺩﻯ ﺇﱃ ﻋﻤـﻞ ﺗﻐﻄﻴـﺔ ﺿـﻌﻴﻔﺔ‬ ‫ﺑﺴﺒﺐ ﻋﺪﻡ ﻣﻌﺮﻓﺔ ﻧﻮﻉ ﺍﻟﺘﻐﻄﻴﺔ ﺍﳌﻨﺎﺳﺒﺔ ﻭ ﻋﺪﻡ ﺍﻻﻫﺘﻤﺎﻡ ﺑﺘﺠﻬﻴﺰ ﺍﻟﺴﻄﺢ ﻭ ﻣﻌﺎﻣﻠـﺔ ﻣـﺎﺩﺓ ﺍﻟﺘﻐﻄﻴـﺔ‬ ‫ﺑﺈﳘﺎﻝ ﺑﻌﺪ ﺇﲤﺎﻡ ﻋﻤﻠﻴﺔ ﺍﻟﺘﻐﻄﻴﺔ ﻭ ﺃﺛﻨﺎﺀ ﺍﻟﺮﺩﻡ ﺑﺎﻹﺿﺎﻓﺔ ﺇﱃ ﺍﳘﺎﻝ ﻋﻤﻠﻴﺔ ﺍﻟﻔﺤﺺ ﺍﻟﻨﻬﺎﺋﻰ ﺑﻌﺪ ﺍﻧﺘـﻬﺎﺀ‬ ‫ﻋﻤﻠﻴﺔ ﺍﻟﺘﻐﻄﻴﺔ‪ .‬ﻭﻳﻮﺟﺪ ﻋﺪﺓ ﻃﺮﻕ ﳊﻤﺎﻳﺔ ﺍﳌﻌﺎﺩﻥ ﺑﺎﻟﺘﻐﻄﻴﺔ ﻧﺬﻛﺮ ﻣﻨﻬﺎ‪:‬‬

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‫ ‪: 8I G &HI :‬‬

‫ﳝﻜﻦ ﺗﻘﺴﻴﻢ ﺃﻧﻮﺍﻉ ﺍﻟﺘﻐﻠﻴﻒ ﻟﻠﻤﻮﺍﺳﲑ ﺍﳌﺪﻓﻮﻧﺔ ﻛﻤﺎ ﻳﻠﻰ ‪-:‬‬ ‫• ﺍﻟﺒﻴﺘﻮﻣﲔ ‪.‬‬ ‫• ﺷﺮﺍﺋﻂ ﺍﻟﺒﻼﺳﺘﻴﻚ ‪.‬‬ ‫• ﺍﻟﺒﻮﱃ ﺍﻳﺜﻠﲔ ) ﻋﺎﱃ – ﻣﻨﺨﻔﺾ ( ﺍﻟﻜﺜﺎﻓﺔ ‪.‬‬ ‫• ﺷﺮﺍﺋﻂ ﻗﻄﺮﺍﻥ ﺍﻟﻔﺤﻢ ‪.‬‬ ‫! ‪: > (* G &HI :‬‬

‫• ﺍﻷﻏﻄﻴﺔ ﺍﻟﻌﻀﻮﻳﺔ ) ﺍﻟﻮﺭﻧﻴﺸﺎﺕ – ﺍﻟﻼﻛﻴﻬﺎﺕ – ﺍﻟﺒﻮﻳﺎﺕ ﺍﳌﺎﻧﻌﺔ ﻟﻠﺘﺂﻛﻞ ( ‪.‬‬ ‫• ﺯﺟﺎﺝ ﺍﻟﺴﲑﺍﻣﻴﻚ ) ﺍﻷﻏﻄﻴﺔ ﺍﻟﻐﲑ ﻣﻌﺪﻧﻴﺔ ﺍﻟﻐﲑ ﻋﻀﻮﻳﺔ( ‪.‬‬ ‫‪@ÝîÛba@óÏ@ŠàÌÛa@âa†‚nbi@ëc@@÷†½bi@”ŠÛa@âa†‚nbi@ëc@@õýĐÜÛ@ñb‘ŠÐÛa@âa†‚nbi@pbãbç†Ûbi@òîĐÌnÛa@ánmë‬‬ ‫‪@ @@Nbèi@æ†È½a@õý@…aŠ½a@òîöbîàîØÛa‬‬ ‫@@‬ ‫! ‪: ( &<78M ) * 8I : K‬‬

‫ﻭﻫﻰ ﻃﺮﻳﻘﺔ ﻣﻌﺮﻭﻓﺔ ﻭ ﺃﺛﺒﺘﺖ ﺟﺪﺍﺭ‪‬ﺎ ﻟﻠﺘﻐﻄﻴﺔ ﻭ ﺍﻟﻮﻗﺎﻳﺔ ﺍﳋﺎﺭﺟﻴﺔ ﻟﻠﺴﻄﻮﺡ ﰱ ﺣﺎﻻﺕ ﺍﻟﺮﻃﻮﺑﺔ ﺍﻟﻌﺎﻟﻴﺔ‬ ‫ﻭ ﰱ ﺍﻟﻮﻗﺎﻳﺔ ﻣﻦ ﺍﻟﻌﻮﺍﻣﻞ ﺍﳉﻮﻳﺔ ﻭ ﰱ ﺍﻹﻧﺸﺎﺀﺍﺕ ﺍﻟﺒﺤﺮﻳﺔ ﻭ ﻫﻰ ﻋﺪﳝﺔ ﺍﳉﺪﻭﻯ ﰱ ﺍﳊﻤﺎﻳﺔ ﺍﻟﺪﺍﺧﻠﻴﺔ ﻭ‬ ‫ﺗﺘﻢ ﺍﳉﻠﻔﻨﺔ ﺑﺎﻟﻐﻤﺮ ﰱ ﻣﺼﻬﻮﺭ ﻓﻠﺰ ﺍﻟﺰﻧﻚ ﻭ ﺍﳉﻠﻔﻨﺔ ﺗﻌﺘﻤﺪ ﰱ ﺍﳌﻘﺎﻡ ﺍﻷﻭﻝ ﻋﻠﻰ ﺃﻥ ﺍﻟﺰﻧﻚ ﳛﺘﻞ ﻣﻜﺎﻧـﹰﺎ‬ ‫ﻣﺘﻘﺪﻣﹰﺎ ﰱ ﺗﺮﺗﻴﺐ ﺍﻟﻔﻠﺰﺍﺕ ﺑﺎﻟﻨﺴﺒﺔ ﳉﻬﺪ ﺍﻟﻘﻄﺐ ﺍﻟﻘﻴﺎﺳﻰ ﻭ ﻳﻼﺣﻆ ﻭﺟﻮﺩ ﻣﺴﺎﻡ ﳎﻬﺮﻳـﺔ ﰱ ﺑﻌـﺾ‬ ‫ﺍﳊﺎﻻﺕ ﺗﺴﺒﺐ ﺧﻠﻖ ﺧﻼﻳﺎ ﳎﻬﺮﻳﺔ ﺑﲔ ﺍﳌﻌﺪﻥ‪.‬‬ ‫ ‪( > (* 8I ) &HI &8EP Q RH;S &O*G &M‬‬

‫ﻭ ﻗﺒﻞ ﺇﺟﺮﺍﺀ ﻋﻤﻠﻴﺔ ﺍﻟﺘﻐﻠﻴﻒ ﳚﺐ ﲡﻬﻴﺰ ﺍﻟﺴﻄﺢ ﺟﻴﺪﺍ ﻋﻦ ﻃﺮﻳﻖ ﺗﻨﻈﻴﻔﻪ ﻭ ﺗﻠﻤﻴﻌﻪ ﺑـﺎﻟﻄﺮﻕ ﺍﻟﻴﺪﻭﻳـﺔ‬ ‫ﺑﺎﺳﺘﺨﺪﺍﻡ ﻓﺮﺷﺔ ﺃﻭ ﺻﻨﻔﺮﺓ ﺃﻭ ﺑﺎﻟﻄﺮﻳﻘﺔ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻭﻫﻰ ﺍﻟﻄﺮﻳﻘﺔ ﺍﻷﻛﺜﺮ ﺍﻧﺘﺸﺎﺭﹰﺍ ﰱ ﺗﻨﻈﻴـﻒ ﺳـﻄﺢ‬ ‫ﺍﳌﺎﺳﻮﺭﺓ ﺑﺎﺳﺘﺨﺪﺍﻡ ﻛﺮﺍﺕ ﺻﻐﲑﺓ ﻣﻦ ﺍﻟﺼﻠﺐ ﻗﻄﺮ )‪ ١‬ﻣﻢ( ﺃﻭ ﺭﻣﻞ ﻧﺎﻋﻢ ﺑﺎﻧﺪﻓﺎﻉ ﻛﺒﲑ ﻋﻦ ﻃﺮﻳـﻖ‬ ‫ﺿﻐﻂ ﺍﳍﻮﺍﺀ ﰒ ﻳﺘﻢ ﺗﻨﻈﻴﻔﻬﺎ ﻣﻦ ﺍﻷﺗﺮﺑﺔ ﺃﻭ ﺍﻟﺸﺤﻮﻣﺎﺕ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﳌﺬﻳﺒﺎﺕ ﺍﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﻛﺎﻟﺰﻳﻠﲔ ﻛﻤـﺎ‬ ‫ﻳﺘﻢ ﺗﻨﻈﻴﻒ ﺍﻟﺴﻄﺢ ﻛﻴﻤﻴﺎﺋﻴﹰﺎ ﺑﺎﻟﺘﺨﻠﻴﻞ ﻋﻦ ﻃﺮﻳﻖ ﻏﻤﺲ ﺍﻷﻟﻮﺍﺡ ﰱ ﺃﺣﻮﺍﺽ ‪‬ﺎ ﺣﺎﻣﺾ ﻭ ﺗـﺴﺘﺨﺪﻡ‬ ‫ﻟﻸﻟﻮﺍﺡ ﺍﳌﺴﺘﻤﺮﺓ ﻭ ﳝﻜﻦ ﺍﻟﺘﻨﻈﻴﻒ ﺃﻳﻀﹰﺎ ﺍﻟﻜﺘﺮﻭﻛﻴﻤﻴﺎﺋﻴﹰﺎ ﲜﻌﻞ ﺍﻟﻠﻮﺡ ﺍﳌﺮﺍﺩ ﺗﻨﻈﻴﻔﻪ ﺁﻧﻮﺩ ﺩﺍﺧﻞ ﺩﺍﺋـﺮﺓ‬ ‫ﻛﻬﺮﺑﺎﺋﻴﺔ ﻛﺎﻣﻠﺔ‪.‬‬

‫‪١٧٠‬‬


‫‪: 8I T 4‬‬

‫ﻳﺘﻢ ﺇﺟﺮﺍﺀ ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﺘﺎﻟﻴﺔ ﻟﺘﺤﺪﻳﺪ ﺻﻼﺣﻴﺔ ﺍﻟﺘﻐﻠﻴﻒ ‪:‬‬ ‫‪ -١‬ﲰﻚ ﺍﻟﺘﻐﻠﻴﻒ ﻭ ﻳﺘﻢ ﻗﻴﺎﺱ ﲰﻚ ﺍﻟﺘﻐﻠﻴﻒ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﳌﻴﻜﺮﻭﻣﻴﺘﺮ ﰱ ﺣﺎﻻﺕ ﺍﻟﺘﻐﻠﻴـﻒ ﺍﻟـﺴﻤﻴﻜﺔ‬ ‫ﻛﻤﺎ ﻳﺘﻢ ﻗﻴﺎﺳﻪ ﺑﺎﻟﻮﺯﻥ ﰱ ﺍﻷﺟﺰﺍﺀ ﺍﻟﺼﻐﲑﺓ ﺣﻴﺚ ﻳﻮﺯﻥ ﺍﻟﺴﻄﺢ ﻗﺒﻞ ﻭ ﺑﻌﺪ ﺍﻟﺘﻜﺴﻴﺔ ‪.‬‬ ‫‪ -٢‬ﻗﻮﺓ ﺍﻟﺘﻼﺻﻖ ﻭ ﻳﺘﻢ ﺍﺧﺘﺒﺎﺭ ﻗﻮﺓ ﺍﻟﺘﻼﺻﻖ ﺑﺸﺪ ﺍﻟﺘﻐﻠﻴﻒ ﻣﻦ ﻋﻠﻰ ﺳﻄﺢ ﺍﳌﻌﺪﻥ ﻭ ﻳﺴﻤﻰ ﺑﺎﻻﺧﺘﺒﺎﺭ‬ ‫ﺍﻻﺗﻼﰱ ﺃﻭ ﺍﺧﺘﺒﺎﺭ ﺳﻘﻮﻁ ﻛﺮﺓ ﻣﻦ ﺍﺭﺗﻔﺎﻉ ﻋﻠﻰ ﺳﻄﺢ ﺍﳌﻌﺪﻥ ‪.‬‬ ‫‪ -٣‬ﺍﻟﻨﻔﺎﺫﻳﺔ ﻳﺘﻢ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻨﻔﺎﺫﻳﺔ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺟﻬﺎﺯ ﺍﺧﺘﺒﺎﺭ ﺍﻟﻔﺠﻮﺍﺕ ﻭ ﻣﻦ ﺍﳋﻄﺄ ﺍﻻﻋﺘﻤﺎﺩ ﻛﻠﻴﺔ ﻋﻠـﻰ‬ ‫ﻫﺬﺍ ﺍﳉﻬﺎﺯ ﻷﻧﻪ ﻻ ﳝﻜﻨﻪ ﺍﻛﺘﺸﺎﻑ ﻛﻞ ﺃﻧﻮﺍﻉ ﺍﻟﺘﻠﻒ ﺍﳌﻮﺟﻮﺩﺓ ﰱ ﺍﻟﻌﺎﺯﻝ ﻣﺜﻞ ﻫﻞ ﺍﻟﻄﺒﻘـﺔ ﺍﻷﻭﱃ‬ ‫ﻣﻦ ﺍﻟﻌﺎﺯﻝ ﺑﺘﺨﺎﻧﺔ ﺃﻡ ﻻ ﻭ ﻫﻞ ﻫﻰ ﻣﻮﺟﻮﺩﺓ ﺃﻡ ﻻ ﺃﻭ ﻣﺎ ﺇﺫﺍ ﻛﺎﻥ ﻫﻨﺎﻙ ﺑﻌﺾ ﺍﻷﺗﺮﺑﺔ ﺑـﲔ ﻟﻔـﺎﺕ‬ ‫ﺍﻟﻌﺎﺯﻝ ﻭ ﺍﻟﺬﻯ ﳝﻜﻦ ﺃﻥ ﻳﻜﺸﻒ ﻋﻨﻪ ﻫﺬﺍ ﺍﳉﻬﺎﺯ ﻫﻮ ﲣﺎﻧﺔ ﺍﻟﻌـﺎﺯﻝ ﻭ ﺧﻠـﻮﻩ ﻣـﻦ ﺍﻟﺜﻘـﻮﺏ ﻭ‬ ‫ﺍﻟﻔﻘﺎﻋﺎﺕ ﻭ ﺍﳌﻮﺍﺩ ﺍﳌﻮﺻﻠﺔ ﺍﻟﻐﺮﻳﺒﺔ ﻭ ﺇﺫﺍ ﻛﺎﻥ ﺍﻟﻌﺎﺯﻝ ﻳﻠﻒ ﰱ ﺍﳌﻮﻗﻊ ﻓﺎﻧﻪ ﳚﺐ ﺃﻥ ﳜﺘﱪ ﻣﺮﺗﲔ ‪.‬‬ ‫• ﺍﻻﺧﺘﺒﺎﺭ ﺍﻻﻭﻝ‪ :‬ﻭ ﻻ ﻳﻠﺰﻡ ﺃﻥ ﺗﻜﻮﻥ ﻋﻠﻰ ﻛﻞ ﺍﳌﺎﺳﻮﺭﺓ ﺑﻞ ﻓﻘﻂ ﰱ ﺍﳌﻨﺎﻃﻖ ﺍﻟﱴ ﳛﺘﻤـﻞ ﻭﺟـﻮﺩ‬ ‫ﺗﻠﻒ ﻓﻴﻬﺎ ﻟﺘﻐﲑ ﺩﺭﺟﺎﺕ ﺍﳊﺮﺍﺭﺓ ﺃﻭ ﺍﻟﺸﺪ ﺍﻟﻼﺯﻡ ﻟﻠﻒ ﻧﺘﻴﺠﺔ ﻃﺮﻳﻘﺔ ﺍﻟﻨﻘﻞ ‪.‬‬ ‫• ﺍﻻﺧﺘﺒﺎﺭ ﺍﻟﺜﺎﱏ ‪ :‬ﻗﺒﻞ ﺗﱰﻳﻞ ﺍﳌﻮﺍﺳﲑ ﺩﺍﺧﻞ ﺍﻟﻨﻔﻖ ﻭ ﳚﺐ ﺃﻥ ﻳﻜﻮﻥ ﺍﻟﺘﻐﻠﻴﻒ ﺩﻗﻴﻘﹰﺎ ﻭ ﻣﻌﲎ ﺫﻟﻚ ﺃﻧﻪ‬ ‫ﳚﺐ ﺍﻟﻜﺸﻒ ﻋﻠﻰ ﺍﳌﻮﺍﺳﲑ ﺑﺪﻗﺔ ﺧﻄﻮﺓ ﺧﻄﻮﺓ ﻭ ﺇﺻﻼﺡ ﻣﺎ ﻗﺪ ﻳﻜﻮﻥ ﺗﺎﻟﻔﹰﺎ ﻭ ﻫﺬﺍ ﻳﻌﻄﻰ ﻛﻔـﺎﺀﺓ‬ ‫ﻼ‪.‬‬ ‫ﻟﻠﺤﻤﺎﻳﺔ ﻭ ﺟﻌﻞ ﺍﳌﻮﺍﺳﲑ ﺗﻌﻴﺶ ﻃﻮﻳ ﹰ‬ ‫‪ -٤‬ﻣﻘﺎﻭﻣﺘﻪ ﻟﻠﺘﺂﻛﻞ ‪.‬‬ ‫‪ZÞb×þa@ÁìÛa@†èu@îÌm NU‬‬ ‫ﺗﻌﺘﻤﺪ ﻧﻈﺮﻳﺔ ﻋﻤﻞ ﻧﻈﺎﻡ ﺍﳊﻤﺎﻳﺔ ﺍﻟﻜﺎﺛﻮﺩﻳﺔ ﻋﻠﻰ ﻣﻨﻊ ﺳﺮﻳﺎﻥ ﺗﻴﺎﺭ ﺍﻟﺘﺂﻛﻞ ﻣﻦ ﺍﳉﺴﻢ ﺍﳌﺮﺍﺩ ﲪﺎﻳﺘﻪ ) ﺧﻂ‬ ‫ﺍﻟﺼﻠﺐ ( ﻓﺈﺫﺍ ﰎ ﻋﻜﺲ ﺍﻟﻔﻮﻟﺖ ﻓﺎﻥ ﺍﻟﺘﻴﺎﺭ ﻳﻨﺴﺎﺏ ﻣﻦ ﺍﻟﺘﺮﺑﺔ ﺇﱃ ﺳﻄﺢ ﺍﳉﺴﻢ ﻭ ﺑـﺬﻟﻚ ﻳﺘﻮﻗـﻒ‬ ‫ﺍﻟﺘﺂﻛﻞ ‪ .‬ﻭ ﺣﻴﺚ ﺃﻥ ﺃﻳﻮﻧﺎﺕ ﺍﻟﺼﻠﺐ ﺃﻭ ﺍﳊﺪﻳﺪ ‪ ++Fe‬ﺗﻨﺘﻘﻞ ﺇﱃ ﺍﻟﻮﺳﻂ ﺍﻻﻟﻜﺘﺮﻭﻟﻴﱴ ﺍﶈﻴﻂ ﺑﺎﳌﻨـﺸﺄ‬ ‫ﺳﻮﺍﺀ ﻛﺎﻥ ﺗﺮﺑﺔ ﺃﻭ ﻣﺎﺀ ﺇﺫﺍ ﻣﺎ ﺗﻮﺍﻓﺮ ﻓﺮﻕ ﺟﻬﺪ ﻛﺎﰱ ﺑﲔ ﺫﻟﻚ ﺍﳉﺴﻢ ﻭ ﺍﻟﻮﺳـﻂ ﻭ ﻧﺘﻴﺠـﺔ ﻟـﺬﻟﻚ‬ ‫ﻳﻨﺴﺎﺏ ﺍﻷﻳﻮﻥ ﺍﳌﻮﺟﺐ ‪ ++Fe‬ﻣﻦ ﺍﳉﺴﻢ ﺇﱃ ﺍﻟﺘﺮﺑﺔ‪ .‬ﻓﺈﻧﻪ ﺇﺫﺍ ﺍﻧﺘﻘﻞ ﺗﻴﺎﺭ ﻛﻬﺮﰉ ﻣﺴﺘﻤﺮ ﻣﻦ ﺍﻟﻮﺳـﻂ‬ ‫ﺍﻻﻟﻜﺘﺮﻭﻟﻴﱴ ﺇﱃ ﺳﻄﺢ ﺍﳌﻨﺸﺄ )ﰱ ﻋﻜﺲ ﺍﲡﺎﻩ ﺗﻴﺎﺭ ﺍﻟﺘﺂﻛﻞ( ﻓﺈﻥ ﺳﻄﺢ ﺍﳌﻨﺸﺄ ﻳﺼﺒﺢ ﻛﺎﺛﻮﺩ ﻭ ﻻ ﻳﺘﺂﻛﻞ‬ ‫‪ ،‬ﻭ ﻫﺬﺍ ﻳﺘﺤﻘﻖ ﺑﻄﺮﻳﻘﺘﲔ‪:‬‬ ‫• ﺍﺳﺘﺨﺪﺍﻡ ﺍﻵﻭﺍﻧﻴﺪ ﺍﳌﺴﺘﻬﻠﻜﺔ ‪.SACRIFICIAL ANODES‬‬ ‫• ﺍﻟﺘﻴﺎﺭ ﺍﳌﺴﻠﻂ ‪.IMPRESSED CURRENT‬‬ ‫ﻭ ﻟﻜﻞ ﻃﺮﻳﻘﺔ ﳎﺎﻝ ﺗﻄﺒﻴﻖ ﻣﻌﲔ ﻭ ﺗﻌﺘﻤﺪ ﺍﳌﻔﺎﺿﻠﺔ ﺑﻴﻨﻬﺎ ﻋﻠﻰ ﻋﻮﺍﻣﻞ ﻓﻨﻴﺔ ﻭ ﺍﻗﺘﺼﺎﺩﻳﺔ ﻭ ﻣﻊ ﺫﻟﻚ ﳝﻜﻦ‬ ‫ﺍﳉﻤﻊ ﺑﲔ ﺍﻟﻨﻈﺎﻣﲔ ﰱ ﻣﺸﺮﻭﻉ ﻭﺍﺣﺪ ‪.‬‬ ‫‪١٧١‬‬


‫ ‪-:&80U * V G & Q- :‬‬

‫ﻋﻨﺪ ﻋﻤﻞ ﲪﺎﻳﺔ ﻛﺎﺛﻮﺩﻳﺔ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﳋﻠﻴﺔ ﺍﳉﻠﻔﺎﻧﻴﺔ ﻳﻌﺮﻑ ﻫﺬﺍ ﺑﻨﻈﺎﻡ ﺍﻵﻧﻮﺩ ﻛﻤﺎ ﺗـﺴﻤﻰ ﺍﻵﻧـﻮﺩﺍﺕ‬ ‫ﺍﻟﺘﻔﻀﻴﻠﻴﺔ ﻛﺬﻟﻚ ﺑﺎﻵﻧﻮﺩﺍﺕ ﺍﳉﻠﻔﺎﻧﻴﺔ ‪ .‬ﻭﻫﺬﻩ ﺗﺼﻨﻊ ﻣﻦ ﻣﻌﺎﺩﻥ ﺃﻭ ﺳﺒﺎﺋﻚ ﺳﺎﻟﺒﺔ ﺍﻟـﺸﺤﻨﺔ ﺑﺎﻟﻨـﺴﺒﺔ‬ ‫ﻟﻠﻤﻨﺸﺄ ﺍﳌﻌﺪﱏ ﺍﳌﻄﻠﻮﺏ ﲪﺎﻳﺘﻪ ﻭ ﲟﻌﲎ ﺁﺧﺮ ﻓﺈ‪‬ﺎ ﺍﻗﺮﺏ ﺇﱃ ﺍﻟﻨﻬﺎﻳﺔ ﺍﻵﻧﻮﺩﻳﺔ ﰱ ﺍﻟﺴﻠـﺴﺔ ﺍﳉﻠﻔﺎﻧﻴـﺔ ﻭ‬ ‫ﻋﻨﺪ ﺩﻓﻦ ﺍﻵﻧﻮﺩ ﰱ ﺍﻟﺘﺮﺑﺔ ﻧﻔﺴﻬﺎ ﺍﻟﱴ ﻓﻴﻬﺎ ﺍﳌﻨﺸﺄ ﺍﳌﻌﺪﱏ ﻭ ﺗﻮﺻﻴﻠﻬﺎ ﺑﺴﻠﻚ ﻣﻮﺻـﻞ ﻓـﺈﻥ ﺍﻵﻧـﻮﺩ‬ ‫ﺍﻟﺘﻔﻀﻴﻠﻰ ﻳﺼﺒﺢ ﺍﻵﻧﻮﺩ ﻟﻠﺨﻠﻴﺔ ﺍﳉﻠﻔﺎﻧﻴﺔ ﻭ ﻳﺘﺂﻛﻞ ﺣﻴﺚ ﻳﺘﻮﻟﺪ ﺗﻴﺎﺭ ﻛﻬﺮﰉ ﻭ ﺍﳌﻨﺸﺄ ﺍﳌﻌـﺪﱏ ﻳـﺼﺒﺢ‬ ‫ﻛﺎﺛﻮﺩﹰﺍ ﻭ ﺗﺘﻢ ﲪﺎﻳﺘﻪ ﻣﻦ ﺍﻟﺘﺂﻛﻞ‪ .‬ﻭ ﺍﳊﻤﺎﻳﺔ ﺑﺎﻵﻧﻮﺩ ﺍﻟﺘﻔﻀﻴﻠﻰ ﳝﻜﻦ ﺍﻥ ﺗﺴﺘﺨﺪﻡ ﰱ ﺍﳌﻨﺎﻃﻖ ﺍﻟﺴﺎﺧﻨﺔ ﺃﻭ‬ ‫ﺍﻟﻌﺪﻭﺍﻧﻴﺔ ﺍﻟﱴ ﻳﺘﻢ ﲢﺪﻳﺪﻫﺎ ﻣﻦ ﺧﻼﻝ ﺍﳌﺴﺎﺣﺔ ﺍﳊﻘﻠﻴﺔ ﻭ ﺩﺭﺍﺳﺔ ﺍﻟﺘﺮﺑﺔ ﺍﻟﱴ ﺳﻮﻑ ﻳﺪﻓﻦ ﻓﻴﻬـﺎ ﺧـﻂ‬ ‫ﺍﳌﻮﺍﺳﲑ ﻭ ﻫﺬﺍ ﻳﺘﻄﻠﺐ ﺃﻥ ﻳﺮﺍﻋﻰ ﺍﻟﺘﻮﺻﻴﻞ ﺍﻟﻜﻬﺮﰉ ﰱ ﺣﺎﻟﺔ ﻭﺟﻮﺩ ﺟﻮﺍﻧﺎﺕ ﺍﳌﻄﺎﻁ ﺑﺎﻟﻨﺴﺒﺔ ﻷﻃـﻮﺍﻝ‬ ‫ﺍﳌﻮﺍﺳﲑ ﺍﳉﺎﺭﻯ ﲪﺎﻳﺘﻬﺎ ﻭ ﻧﻔﺲ ﺍﳊﻤﺎﻳﺔ ﳝﻜﻦ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﳊﻤﺎﻳﺔ ﺧﺰﺍﻧﺎﺕ ﺍﻟﺼﻠﺐ ‪ ،‬ﻭ ﻣﻮﺍﺳﲑ ﺍﻟﺼﻠﺐ‬ ‫ﻭﻛﺬﻟﻚ ﺑﻌﺾ ﺍﳌﻌﺪﺍﺕ ﺍﳌﻌﺪﻧﻴﺔ ﳌﻌﺎﳉﺔ ﺍﳌﻴﺎﻩ ‪.‬‬

‫‪RISER‬‬

‫‪STUD‬‬

‫‪Fe ANODE‬‬

‫‪SERVICE‬‬

‫‪++‬‬

‫‘‪@ @óãbÐÜ¦a@…ìãŁbi@òß†ä@@ÂìĐ¨@òí…ìqbØÛa@òíbà§a@âbÄã@XM@X@ÝØ‬‬

‫‪١٧٢‬‬


‫@‪ X Y ZE‬ء ‪:‬‬

‫ﻳﺴﺘﺨﺪﻡ ﻋﺎﺩﺓ ﻣﻌﺪﻥ ﺍﻟﺰﻧﻚ ﻭ ﺍﳌﺎﻏﻨﺴﻴﻮﻡ ﻛﺂﻧﻮﺩﺍﺕ ﺗﻔﻀﻴﻠﻴﺔ ﳊﻤﺎﻳﺔ ﺍﻧﺸﺎﺀﺍﺕ ﺍﳊﺪﻳﺪ ﻭ ﺍﻟﺼﻠﺐ ﻭ ﺍﻷﻛﺜـﺮ‬ ‫ﺍﺳﺘﺨﺪﺍﻣﹰﺎ ﻫﻰ ﺁﻭﺍﻧﻴﺪ ﺍﳌﺎﻏﻨﺴﻴﻮﻡ ﻷ‪‬ﺎ ﺗﻨﺘﺞ ﺟﻬﺪ ﺧﻠﻴﺔ ﺃﻋﻠﻰ ﻣﻦ ﺁﻭﺍﻧﻴﺪ ﺍﻟﺰﻧـﻚ ‪ .‬ﻭ ﺗـﺴﺘﺨﺪﻡ ﺁﻭﺍﻧﻴـﺪ‬ ‫ﺍﳌﺎﻏﻨﺴﻴﻮﻡ ﻟﻠﺤﻤﺎﻳﺔ ﰱ ﺍﻟﺘﺮﺑﺔ ﺣﻴﺚ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻜﻬﺮﺑﻴﺔ ﺃﻗﻞ ﻣﻦ ‪ ٥٠٠٠‬ﺃﻭﻡ ﻭ ﺗﺴﺘﺨﺪﻡ ﺁﻭﺍﻧﻴـﺪ ﺍﻟﺰﻧـﻚ ﰱ‬ ‫ﺍﻟﺘﺮﺑﺔ ﺫﺍﺕ ﻣﻘﺎﻭﻣﺔ ‪ ١٠٠٠‬ﺃﻭﻡ ﺃﻭ ﺃﻗﻞ ‪.‬‬

‫ﺧﺪﺵ ﰱ ﺍﻟﺘﻐﻠﻴﻒ‬

‫ﻗﻄﺐ ﻣﺎﻏﻨﺴﻴﻮﻡ‬

‫ﻣﺴﺎﺭ ﺗﻴﺎﺭ‬ ‫‪I‬‬

‫ﺨﻁ ﺍﻝﺼﻠﺏ ﺍﻝﻤﺩﻓﻭﻥ‬

‫‘‪@ @òØÜèn½a@†îãaëŁbi@òíbà§a@âbÄã@Y@–@X@ÝØ‬‬ ‫^]> (\ <[ ‪: ( A‬‬ ‫•‬

‫ﻻ ﳛﺘﺎﺝ ﺍﻟﻨﻈﺎﻡ ﺇﱃ ﻣﺼﺪﺭ ﻛﻬﺮﺑﺎﺀ ﺧﺎﺭﺟﻰ ﻟﻠﺘﺸﻐﻴﻞ ‪.‬‬

‫•‬

‫ﻻ ﳛﺪﺙ ﺗﺪﺍﺧﻞ ﻛﻬﺮﰉ ﻣﻊ ﺍﳌﺮﺍﻓﻖ ﺍﻷﺧﺮﻯ ‪.‬‬

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‫ﺫﺍﺕ ﺗﻜﻠﻔﺔ ﻣﻘﺒﻮﻟﺔ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻸﳘﻴﺔ ﺍﻟﻜﱪﻯ ﺍﻟﱴ ﻳﺆﺩﻳﻬﺎ ﻟﻠﺸﺒﻜﺔ ‪.‬‬

‫‪: _G-P‬‬ ‫•‬

‫ﻓﺮﻕ ﺍﳉﻬﺪ ﺍﳊﺎﻓﺰ ﻟﺪﻓﻊ ﺍﻟﺘﻴﺎﺭ ﺍﻟﻜﻬﺮﺑﺎﺋﻰ ﺻﻐﲑ ﺟﺪﹰﺍ ‪.‬‬

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‫ﻛﻤﻴﺔ ﺍﻟﺘﻴﺎﺭ ﺍﻟﻜﻬﺮﰉ ﺍﳌﺘﻮﻟﺪﺓ ﻋﻨﻪ ﳏﺪﻭﺩﺓ ‪.‬‬

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‫ﻣﻜﻠﻒ ﺟﺪﹰﺍ ﳊﻤﺎﻳﺔ ﺍﳌﻮﺍﺳﲑ ﺫﺍﺕ ﺍﻷﻗﻄﺎﺭ ﺍﻟﻜﺒﲑﺓ ﻭ ﻛﺬﻟﻚ ﺭﺩﻳﺌﺔ ﺍﻟﺘﻐﻠﻴﻒ‪.‬‬

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‫ﻻ ﻳﺆﺩﻯ ﺍﻟﻐﺮﺽ ﺇﺫﺍ ﺍﺳﺘﺨﺪﻡ ﰱ ﺗﺮﺑﺔ ﺫﺍﺕ ﻣﻘﺎﻭﻣﺔ ﻋﺎﻟﻴﺔ ﻟﻠﺘﺂﻛﻞ‪.‬‬

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‫ﻭ ﺗﺴﺘﺨﺪﻡ ﺃﻗﻄﺎﺏ ﺍﳌﺎﻏﻨﺴﻴﻮﻡ ﺯﻧﺔ ‪ ٧,٧‬ﻛﺠﻢ ﻭ ﺍﳌﺪﻓﻮﻧﺔ ﰱ ﻣﺮﻛﺐ ﻛﻴﻤﻴـﺎﺋﻰ ﻣـﻦ ﺍﳉـﺒﺲ ﻭ‬ ‫ﺍﻟﺒﻨﺘﻮﻧﻴﺖ ﻭ ﺍﻟﺼﻮﺩﻳﻮﻡ ﺑﻨﺴﺐ ﳏﺪﺩﺓ ﺑﻐﺮﺽ ﺍﺳﺘﻘﺮﺍﺭ ﺍﳉﻬﺪ ﻭ ﺗﻮﺯﻳﻊ ﺍﺳﺘﻬﻼﻙ ﺍﻵﻧﻮﺩ ﺑﺎﻧﺘﻈﺎﻡ ‪.‬‬

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‫ﻭ ﺗﻮﺯﻉ ﺍﻷﻗﻄﺎﺏ ﻋﻠﻰ ﻣﺴﺎﺭ ﺧﻂ ﺍﻟﺼﻠﺐ ﺃﻣﺎ ﻓﺮﺍﺩﻯ ﺃﻭ ﰱ ﳎﺎﻣﻴﻊ ﻋﻠﻰ ﺟﺎﻧﱮ ﺍﳋﻂ ﺍﳌـﺮﺩﻭﻡ ﻭ‬ ‫ﻋﻠﻰ ﻣﺴﺎﻓﺎﺕ ﺑﻴﻨﻴﺔ ﳏﺪﺩﺓ ﻭ ﺫﻟﻚ ﺗﺒﻌﹰﺎ ﻟﻘﻄﺮ ﺧﻂ ﺍﻟﻐﺎﺯ ‪.‬‬

‫‪١٧٣‬‬


‫‪-: ?8@ =4 T U$ 8P ` HQS ? *

‫ﳏﻮﺭ ﺍﻟﻘﻄﺐ ﻳﻮﺍﺯﻯ ﳏﻮﺭ ﺧﻂ ﺍﻟﺼﻠﺐ ‪.‬‬

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‫ﺍﳌﺴﺎﻓﺔ ﺑﲔ ﺍﻟﺮﺍﺳﻢ ﺍﳉﺎﻧﱮ ﻟﻠﻤﺎﺳﻮﺭﺓ ﻭ ﻗﻄﺐ ﺍﳌﺎﻏﻨﺴﻴﻮﻡ ﻻ ﺗﺰﻳﺪ ﻋﻦ ‪ ٣‬ﻣﺘﺮ ‪.‬‬

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‫ﻣﺴﺘﻮﻯ ﺍﻟﻘﻄﺐ ﻳﻜﻮﻥ ﺃﺳﻔﻞ ﻣﺴﺘﻮﻯ ﺧﻂ ﺍﻟﻐﺎﺯ ﲟﺴﺎﻓﺔ ﻻ ﺗﻘﻞ ﻋﻦ ‪ ٣٠‬ﺳﻢ ‪.‬‬

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‫ﻳﻜﻮﻥ ﺍﻟﻮﺳﻂ ﺑﲔ ﺍﻟﻘﻄﺐ ﻭ ﺍﳋﻂ ﺧﺎﻟﻴﹰﺎ ﲤﺎﻣﹰﺎ ﻣﻦ ﺃﻯ ﻣﺮﻓﻖ ﺃﻭ ﻋﺎﺋﻖ ﳝﻨﻊ ﻣﺮﻭﺭ ﺍﻟﺘﻴﺎﺭ ﺇﱃ ﺧﻂ‬ ‫ﺍﻟﺼﻠﺐ ‪.‬‬

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‫ﺗﺮﺩﻡ ﻣﻘﱪﺓ ﺍﻟﻘﻄﺐ ﺑﻨﻔﺲ ﺍﻟﺘﺮﺑﺔ ﺍﶈﻔﻮﺭﺓ ﻣﻦ ﺍﳋﻨﺪﻕ ‪.‬‬

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‫ﺍﻻﻟﺘﺰﺍﻡ ﺑﺄﻟﻮﺍﻥ ﺃﺳﻼﻙ ﺗﻮﺻﻴﻞ ﺍﻷﻗﻄﺎﺏ ﺑﺎﻟﻨﺴﺒﺔ ﻻﲡﺎﻩ ﻣﺮﻭﺭ ﺍﻟﻐﺎﺯ ﺑﺎﳋﻂ ﻟﺴﻬﻮﻟﺔ ﺍﻟﺘﻌﺮﻑ ﻋﻠﻰ‬ ‫ﻣﻮﺍﺿﻊ ﺍﻷﻗﻄﺎﺏ ﰱ ﻣﺮﺍﺣﻞ ﺍﻟﺘﺸﻐﻴﻞ ﻭ ﺍﻟﺼﻴﺎﻧﺔ ‪.‬‬

‫‪: 78M - V A [ 8‬‬

‫ﻫﺬﺍ ﺍﻟﻨﻈﺎﻡ ﻳﺼﺒﺢ ﻣﻌﻘﺪﹰﺍ ﻋﻨﺪﻣﺎ ﻳﻜﻮﻥ ﻫﻨﺎﻙ ﻣﺼﺎﻋﺪ ﻣﺎﻏﻨﺴﻴﻮﻡ ﻣﺘﻌـﺪﺩﺓ ﺗﻌﻤـﻞ ﻛﻤﺨـﺎﺭﺝ ﻟﻠﺘﻴـﺎﺭ‬ ‫ﻻﺣﺘﻤﺎﻝ ﺇﺻﺎﺑﺔ ﺑﻌﺾ ﺍﻷﺟﺰﺍﺀ ﺑﺎﻟﺘﻠﻒ ﻭ ﻫﺬﺍ ﻳﻌﲎ ﺿﺮﻭﺭﺓ ﺍﳌﺮﺍﺟﻌﺔ ﻋﻠﻰ ﻧﻘﺎﻁ ﻣﺘﻌﺪﺩﺓ ﻭ ﺍﻟﺘﻠﻒ ﺍﻟﺬﻯ‬ ‫ﳝﻜﻦ ﺃﻥ ﻳﺘﻌﺮﺽ ﻟﻪ ﺍﻟﻨﻈﺎﻡ ﻫﻮ ‪-:‬‬ ‫•‬

‫ﺍﺳﺘﻬﻼﻙ ﻣﺼﻌﺪ ﺃﻭ ﺍﻛﺜﺮ ﺑﺎﻻﺳﺘﻌﻤﺎﻝ ﺍﻟﻌﺎﺩﻯ ﺃﻭ ﺑﺎﻟﺘﺄﺛﲑﺍﺕ ﺍﶈﻠﻴﺔ ﻭ ﻳﻈﻬﺮ ﺫﻟـﻚ ﻣـﻦ ﺧـﻼﻝ‬ ‫ﺍﳔﻔﺎﺽ ﺍﳉﻬﺪ ﻭ ﺍﻟﺘﻴﺎﺭ ‪.‬‬

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‫ﺗﻠﻒ ﺃﻭ ﺗﺪﻣﲑ ﺍﻷﺳﻼﻙ ﺍﳌﻮﺻﻠﺔ ‪.‬‬

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‫ﻓﻘﺪ ﺍﻟﺘﻴﺎﺭ ﻧﺘﻴﺠﺔ ﺟﻔﺎﻑ ﺍﻟﺘﺮﺑﺔ ﺍﻟﻐﲑ ﻋﺎﺩﻯ ﺳﻮﺍﺀ ﻋﻨﺪ ﺍﳌﺎﺳﻮﺭﺓ ﺃﻭ ﻋﻨﺪ ﺍﳌﺼﻌﺪ ﺃﻭ ﻛﻠﻴﻬﻤﺎ ‪.‬‬

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‫ﺍﻻﺗﺼﺎﻝ ﺍﻟﻜﻬﺮﰉ ﺑﲔ ﺍﳋﻂ ﻭ ﺃﻯ ﻣﻨﺸﺄ ﻣﻌﺪﱏ ﺁﺧﺮ ﻏﲑ ﺩﺍﺧﻞ ﰱ ﺍﻻﻋﺘﺒﺎﺭ ‪.‬‬

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‫ﺗﻠﻒ ﺍﻟﻌﺰﻝ ‪.‬‬

‫! ‪: =8U T G & Q-‬‬

‫ ﻣﻨﻈﻮﻣﺎﺕ ﺍﳊﻤﺎﻳﺔ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﻟﺘﻴﺎﺭ ﺍﳌﺴﻠﻂ ‪ Impressed Current‬ﺗﺄﰐ ﺍﻟﺘﺴﻤﻴﺔ ﻣﻦ ﻛﻮﻥ ﺗﻴـﺎﺭ‬‫ﺍﳊﻤﺎﻳﺔ ﻣﺴﻠﻂ ﻣﻦ ﻣﺼﺪﺭ ﺧﺎﺭﺟﻲ ﻭﺗﺘﻜﻮﻥ ﺍﳌﻨﻈﻮﻣﺔ ﻋﺎﺩﺓ ﻣﻦ ﺍﻷﺟﺰﺍﺀ ﺍﻟﺘﺎﻟﻴﺔ‪ - :‬ﻣﺼﺪﺭ ﺗﻴﺎﺭ ﻣـﺴﺘﻤﺮ‬ ‫‪ - Dc Source‬ﺃﻗﻄﺎﺏ ﺗﻀﺤﻴﺔ )ﺃﻧﻮﺩﺍﺕ( ‪ -‬ﻛﺎﺑﻼﺕ ﻭﺃﺳﻼﻙ ﻟﻠﺮﺑﻂ ﻣﻊ ﻣﻠﺤﻘﺎ‪‬ﺎ‬ ‫ﻳﺴﺘﺨﺪﻡ ﻋﺎﺩﺓ ﻣﺼﺪﺭ ﺗﻴﺎﺭ ﻣﺴﺘﻤﺮ ﻣﻦ ﻧﻮﻉ ﳏﻮﻟﺔ‪/‬ﻣﻌﺪﻟﺔ ‪ Transformer/Rectifier‬ﻋﻨـﺪ ﺗـﻮﻓﺮ‬ ‫ﻣﺼﺪﺭ ﻗﺮﻳﺐ ﻟﻠﺘﻐﺬﻳﺔ ﺑﺎﻟﻄﺎﻗﺔ ﺍﻟﻜﻬﺮﺑﺎﺋﻴﺔ ﻭﻫﻮ ﺍﳌﻔﻀﻞ ﳍﺬﺍ ﺍﻷﺳﻠﻮﺏ ﻣﻦ ﺍﳊﻤﺎﻳﺔ ﻻﺳـﺒﺎﺏ ﺗـﺸﻐﻴﻠﻴﺔ‬ ‫ﻭﺍﻗﺘﺼﺎﺩﻳﺔ‪ ،‬ﻭﰲ ﺣﺎﻟﺔ ﻋﺪﻡ ﺗﻮﻓﺮ ﺫﻟﻚ ﳝﻜﻦ ﺍﺳﺘﺨﺪﺍﻡ ﻣﻮﻟﺪﺍﺕ ﻛﻬﺮﺑﺎﺀ ﺣﺮﺍﺭﻳﺔ ﻋﻨﺪ ﺗﻮﻓﺮ ﻏﺎﺯ ﻛﻮﻗﻮﺩ‬ ‫ﻟﺘﺸﻐﻴﻠﻬﺎ ﺃﻭ ﺍﺳﺘﺨﺪﺍﻡ ﻣﻨﻈﻮﻣﺎﺕ ﺗﻌﻤﻞ ﺑﺎﻟﻄﺎﻗﺔ ﺍﻟﺸﻤﺴﻴﺔ ﻛﻤﺎ ﳝﻜﻦ ﺍﺳﺘﺨﺪﺍﻡ ﻣﻮﻟﺪﺍﺕ ﺗﻌﻤﻞ ﺑﻄﺎﻗـﺔ‬ ‫‪١٧٤‬‬


‫ﺍﻟﺮﻳﺎﺡ ﺃﻭ ﺍﺳﺘﺨﺪﺍﻡ ﻣﻮﻟﺪﺍﺕ ﻛﻬﺮﺑﺎﺋﻴﺔ )ﺩﻳﺰﻝ(‪ .‬ﺃﻣﺎ ﺃﻗﻄﺎﺏ ﺍﻟﺘﻀﺤﻴﺔ ﻓﻬﻲ ﻋﺎﺩﺓ ﺗﻜﻮﻥ ﻣﻦ ﺣﺪﻳـﺪ –‬ ‫ﺳﻠﻴﻜﻮﻥ ﺃﻭ ﺍﻟﻜﺮﺍﻓﺎﻳﺖ‪ .‬ﻳﺘﻄﻠﺐ ﺍﺳﺘﺨﺪﺍﻡ ﺍﳊﻤﺎﻳﺔ ﺍﻟﻜﺎﺛﻮﺩﻳﺔ ﻣﻦ ﺍﻟﻨﻮﻉ ﺍﻟﻘﺴﺮﻱ ﰲ ﺣﺎﻟـﺔ ﺍﳊﺎﺟـﺔ‬ ‫ﳊﻤﺎﻳﺔ ﺧﻄﻮﻁ ﺍﻷﻧﺎﺑﻴﺐ ﻭﻗﻮﺍﻋﺪ ﺍﳋﺰﺍﻧﺎﺕ ﺫﺍﺕ ﺍﻷﺳﻄﺢ ﺍﻟﻜﺒﲑﺓ ﻭﺍﻟﱵ ﺗﺘﻄﻠﺐ ﺗﻴـﺎﺭ ﲪﺎﻳـﺔ ﻋـﺎﱄ‬ ‫ﻭﻟﻔﺘﺮﺍﺕ ﻃﻮﻳﻠﺔ ﲤﺘﺪ ﻋﻠﻰ ﻣﺪﻯ ﻋﻤﺮ ﺍﳌﻨﺸﺂﺕ ﺍﻟﱵ ﺗﻌﻮﺩ ﺇﻟﻴﻬﺎ )‪ ٢٠‬ﺳﻨﺔ ﻓـﺄﻛﺜﺮ(‪ .‬ﺗﺘـﻮﻓﺮ ﰲ ﻫـﺬﻩ‬ ‫ﺍﳌﻨﻈﻮﻣﺎﺕ ﺇﻣﻜﺎﻧﻴﺔ ﺍﻟﺴﻴﻄﺮﺓ ﻋﻠﻰ ﺍﳊﻤﺎﻳﺔ ﻭﻣﺮﺍﻗﺒﺘﻬﺎ ﺍﳌﺴﺘﻤﺮﺓ‪.‬‬ ‫‪ï™‰c@āìy‬‬ ‫‪@ @Þý@‰bînÛa@ôŠß‬‬ ‫@‪lìjãþa@µg@ā‰þa‬‬ ‫‪kîibãc@Á‬‬

‫‪ÁÜ½a@‰bînÛa@â†‚nm@òí…ìqb×@òíb»@òĐª‬‬ ‫‪=8U T >a 6- :$ & EF &$-[< bcTS d-F‬‬

‫ﲢﻮﻱ ﺍﻷﺣﻮﺍﺽ ﺍﻷﺭﺿﻴﺔ ﻋﻠﻰ ﺍﻻﻧﻮﺩﺍﺕ ﻭﻣﻦ ﺍﻻﻧـﻮﺩﺍﺕ ﺍﻟـﺸﺎﺋﻌﺔ ﺍﻻﺳـﺘﺨﺪﺍﻡ ﻫـﻲ ﺍﻧـﻮﺩﺍﺕ‬ ‫ﺣﺪﻳﺪ‪/‬ﺳﻠﻴﻜﻮﻥ ‪ FeSi‬ﻭﺍﻟﺬﻱ ﻳﺒﻠﻎ ﻣﻌﺪﻝ ﺍﺳﺘﻬﻼﻛﻪ ﻣﻦ ‪ ٠,١‬ﻟﻐﺎﻳﺔ ‪ ٠,٥‬ﻛﺠﻢ‪/‬ﺃﻣﺒﲑ‪/‬ﺳـﻨﺔ ﻭﻫﻨـﺎﻙ‬ ‫ﻛﺬﻟﻚ ﺍﻧﻮﺩﺍﺕ ﻣﻦ ﻧﻮﻉ ﺍﳉﺮﺍﻓﻴﺖ ﻭﺍﻟﱵ ﻳﺒﻠﻎ ﺍﺳﺘﻬﻼﻛﻬﺎ ﻣﻦ ‪ ٠,١‬ﻟﻐﺎﻳﺔ ‪ ٢‬ﻛﺠﻢ‪/‬ﺃﻣﺒﲑ‪/‬ﺳـﻨﺔ‪ .‬ﺑﻌـﺪ‬ ‫ﲢﺪﻳﺪ ﻛﺜﺎﻓﺔ ﺍﻟﺘﻴﺎﺭ ﺍﳌﻄﻠﻮﺏ ﻟﺘﻮﻓﲑ ﺍﳊﻤﺎﻳﺔ ﻭﲟﻌﺮﻓﺔ ﺍﳌﺴﺎﺣﺔ ﺍﻟﺴﻄﺤﻴﺔ ﻟﻠﻤﻌﺪﻥ ﺍﳌﺮﺍﺩ ﲪﺎﻳﺘـﻪ ﻭﻋﻤـﺮ‬ ‫ﺍﳌﻨﻈﻮﻣﺔ ﺍﳌﻔﺘﺮﺽ ﺑﺎﻟﺴﻨﻮﺍﺕ ﳝﻜﻦ ﺣﺴﺎﺏ ﺍﻟﻮﺯﻥ ﺍﻟﻜﻠﻲ ﻟﻼﻧﻮﺩﺍﺕ ﺍﻟﱵ ﻳﺘﻄﻠﺐ ﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﻭﺑﺎﻟﺘـﺎﱄ‬ ‫ﺍﺣﺘﺴﺎﺏ ﺃﻋﺪﺍﺩﻫﺎ ﺣﺴﺐ ﻭﺯﻥ ﺍﻷﻧﻮﺩ ﺍﻟﻮﺍﺣﺪ‪ .‬ﺗﺪﻓﻦ ﺍﻻﻧﻮﺩﺍﺕ ﻋﺎﺩﺓ ﰲ ﻣﺴﺤﻮﻕ ﻣﻦ ﺍﻟﻔﺤﻢ ﺍﳊﺠﺮﻱ‬ ‫ﻟﺘﻘﻠﻴﻞ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺘﻤﺎﺱ ﺑﲔ ﺍﻻﻧﻮﺩﺍﺕ ﻭﺍﻟﺘﺮﺑﺔ ﻭﺑﺎﻟﺘﺎﱄ ﺗﻘﻠﻴﻞ ﺟﻬﺪ ﺍﻟﺪﺍﺋﺮﺓ ﺍﻟﻜﻬﺮﺑﺎﺋﻴﺔ ﻟﺪﻓﻊ ﺗﻴﺎﺭ ﺍﳊﻤﺎﻳﺔ‬ ‫ﻭﺗﻘﻠﻴﻞ ﺍﺳﺘﻬﻼﻙ ﺍﻻﻧﻮﺩﺍﺕ‪ .‬ﻃﺮﻳﻘﺔ ﺩﻓﻦ ﺍﻻﻧﻮﺩﺍﺕ ﺗﻌﺘﻤﺪ ﻋﻠﻰ ﻃﺒﻴﻌﺔ ﺍﳌﻨﻄﻘﺔ ﻭﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻨﻮﻋﻴﺔ ﻟﻠﺘﺮﺑﺔ‪،‬‬ ‫ﻓﺄﻥ ﻛﺎﻧﺖ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻨﻮﻋﻴﺔ ﻭﺍﻃﺌﺔ ﻭﻣﺴﺘﻮﻯ ﺍﳌﻴﺎﻩ ﻋﺎﱄ ﳝﻜﻦ ﺍﺳﺘﺨﺪﺍﻡ ﺃﺣﻮﺍﺽ ﺃﺭﺿﻴﺔ ﺳﻄﺤﻴﺔ ﻭﺗﺪﻓﻦ‬ ‫ﺍﻻﻧﻮﺩﺍﺕ ﺃﻓﻘﻴﺎ ﻋﻠﻰ ﺃﻋﻤﺎﻕ ﻗﻠﻴﻠﺔ ‪ ٣-٢‬ﻣﺘﺮ ﺑﻴﻨﻤﺎ ﻳﺘﻄﻠﺐ ﺩﻓﻦ ﺍﻻﻧﻮﺩﺍﺕ ﻋﻤﻮﺩﻳﺎ ﻋﻠﻰ ﺃﻋﻤﺎﻕ ﺃﻛـﱪ‬ ‫‪‬ﺪﻑ ﺍﻟﻮﺻﻮﻝ ﺇﱃ ﻃﺒﻘﺎﺕ ﺍﻟﺘﺮﺑﺔ ﻭﺍﻃﺌﺔ ﺍﳌﻘﺎﻭﻣﺔ‪ .‬ﺃﻣﺎ ﰲ ﺍﳌﻨﺎﻃﻖ ﺫﺍﺕ ﺍﳌﻘﺎﻭﻣﺔ ﺍﻟﻨﻮﻋﻴﺔ ﺍﳌﺮﺗﻔﻌﺔ ﺟـﺪﺍ‬ ‫ﻭﺍﻟﱵ ﺗﻜﻮﻥ ﺃﻛﺜﺮ ﻣﻦ ‪ ٥٠‬ﺍﻭﻡ‪.‬ﻣﺘﺮ ﻭﻟﻐﺮﺽ ﺍﻟﻮﺻﻮﻝ ﺇﱃ ﺍﻟﻄﺒﻘﺎﺕ ﺍﻟﺴﻔﻠﻰ ﺫﺍﺕ ﺍﳌﻘﺎﻭﻣـﺔ ﺍﻟﻨﻮﻋﻴـﺔ‬ ‫ﺍﻟﻮﺍﻃﺌﺔ ﻳﺘﻄﻠﺐ ﺍﻻﻣﺮ ﺣﻔﺮ ﺃﺣﻮﺍﺽ ﺃﺭﺿﻴﺔ ﻋﻤﻴﻘﺔ ﺣﻴﺚ ﳝﻜﻦ ﺃﻥ ﻳﻜﻮﻥ ﺍﻟﻌﻤﻖ ‪ ٣٠‬ﻣﺘﺮ ﻓﺎﻛﺜﺮ‪ .‬ﺗﻮﺻﻞ‬ ‫ﺍﻻﻧﻮﺩﺍﺕ ﺑﺴﻠﻚ ﻛﻬﺮﺑﺎﺋﻲ ﺇﱄ ﻣﺼﺪﺭ ﺍﻟﻄﺎﻗﺔ ﺍﻟﻜﻬﺮﺑﺎﺋﻴﺔ )ﻣﺼﺪﺭ ﺍﻟﺘﻴﺎﺭ(‪ ،‬ﺑﻴﻨﻤﺎ ﺗﻮﺻﻞ ﻛﺎﻓﺔ ﺍﻻﻧﻮﺩﺍﺕ‬ ‫ﻓﻴﻤﺎ ﺑﻴﻨﻬﺎ ﻋﻠﻰ ﺍﻟﺘﻮﺍﺯﻱ‪.‬‬ ‫‪١٧٥‬‬


‫‪>fX< b8P g"!f R8U **+ *h 6-8‬‬

‫ﺻﺪﺃ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﰲ ﺍﳌﻨﺸﺂﺕ ﺍﳋﺮﺳﺎﻧﻴﺔ ﻳﻬﺪﺩ ﺍﻻﺳﺘﺜﻤﺎﺭﺍﺕ ﺍﻟﻌﻘﺎﺭﻳﺔ ﻭﻳﺴﺘﱰﻑ ﺍﻟﻜﺜﲑ ﰲ ﺃﻋﻤـﺎﻝ‬ ‫ﺍﻹﺻﻼﺡ ﻭﺍﳊﻤﺎﻳﺔ ﻟﻠﻤﻨﺸﺎﺕ ﺍﻟﻌﺎﻣﺔ ﻭﺍﳋﺎﺻﺔ ‪ ،‬ﻭﻻ ﺑﺪ ﻣﻦ ﺍﺳﺘﺨﺪﺍﻡ ﺍﺣﺪﺙ ﺍﻟﻄﺮﻕ ﳊﻤﺎﻳﺔ ﻭﺇﺻـﻼﺡ‬ ‫ﺍﳌﻨﺸﺎﺕ ﻟﻠﻤﺤﺎﻓﻈﺔ ﻋﻠﻲ ﺍﻟﺜﺮﻭﺍﺕ ﺍﻟﻮﻃﻨﻴﺔ ‪.‬ﻳﺘﻜﻮﻥ ﺍﻟﺼﺪﺃ ﺑﻮﺟﻪ ﻋﺎﻡ ﻧﺘﻴﺠﺔ ﺗﻌﺮﺽ ﺍﳊﺪﻳﺪ ﻟﻠﻬﻮﺍﺀ ﻭﺍﳌﺎﺀ‬ ‫‪,‬ﻭﺍﳋﺮﺳﺎﻧﺔ ﺑﻄﺒﻴﻌﺘﻬﺎ ﻣﺎﺩﺓ ﻣﺴﺎﻣﻴﺔ ﲢﻮﻱ ﺭﻃﻮﺑﺔ ﻭﻟﺬﻟﻚ ﻣﻦ ﺍﻟﻄﺒﻴﻌﻲ ﺣﺪﻭﺙ ﺻﺪﺃ ﻟﻠﺤﺪﻳﺪ ﺑﺪﺍﺧﻠﻬﺎ‬ ‫ﻟﻜﻦ ﻟﻴﺲ ﺑﺎﻟﻀﺮﻭﺭﺓ ﺣﺪﻭﺙ ﺍﻟﺼﺪﺃ ﻟﻠﺤﺪﻳﺪ ﰲ ﺍﳋﺮﺳﺎﻧﺔ ﻻﻥ ﺍﳋﺮﺳﺎﻧﺔ ﻣﺎﺩﺓ ﻗﻠﻮﻳﺔ ﻭﻫﻲ ﻣﻌﺎﻛـﺴﺔ‬ ‫ﻟﻸﲪﺎﺽ ﻭﺑﺎﻟﺘﺎﱄ ﻓﺈﻥ ﺍﳋﺮﺳﺎﻧﺔ ﺗﻘﻮﻡ ﲝﻤﺎﻳﺔ ﺍﳊﺪﻳﺪ ﻣﻦ ﺍﻟﺼﺪﺃ ﺑﺘﻜﻮﻥ ﻃﺒﻘﺔ ﻗﻠﻮﻳﺔ ﻛﺜﻴﻔﺔ ﲤﻨﻊ ﺣـﺪﻭﺙ‬ ‫ﺍﻟﺼﺪﺃ ﻃﺒﻘﺔ ﲪﺎﻳﺔ ﺳﻠﺒﻴﺔ ‪.‬ﻭﳛﺪﺙ ﺍﻟﺼﺪﺃ ﻧﺘﻴﺠﺔ ﺗﻜﺴﲑ ﻃﺒﻘﺔ ﺍﳊﻤﺎﻳﺔ ﺍﻟﺴﻠﺒﻴﺔ ﻭﻇﻬﻮﺭ ﺍﻟـﺼﺪﺃ ﻋﻠـﻲ‬ ‫ﺳﻄﺢ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ‪ ,‬ﻳﺒﺪﺃ ﺻﺪﺃﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﰲ ﺍﻟﺘﻜﻮﻥ ﻣﻦ ﻧﻘﺮﺓ ﺻﻐﲑﻩ ﰲ ﺍﻟﺴﻴﺦ ﰒ ﺗﺰﺩﺍﺩﻫـﺬﻩ‬ ‫ﺍﻟﻨﻘﺮ ﻭﳛﺪﺙ ﺍﲢﺎﺩ ﺑﻴﻨﻬﺎ ﳑﺎ ﻳﻜﻮﻥ ﺍﻟﺼﺪﺃ ﺍﻟﻌﺎﻡ ‪ .‬ﻭﻫﻨﺎﻙ ﺃﺳﺒﺎﺏ ﺃﺧﺮﻯ ﻟﺘﻜﻮﻥ ﺍﻟﺼﺪﺃ ﻭﻫﻲ ﺍﻟﺒﻜﺘﲑﻳﺎ‪.‬‬ ‫ﻭﻫﻲ ﺑﺎﻟﻐﺎﻟﺐ ﻣﻮﺟﻮﺩﺓ ﺑﺎﻟﺘﺮﺑﺔ ﻭﺗﻘﻮﻡ ﺑﺘﺤﻮﻳﻞ ﺍﻷﻣﻼﺡ ﻭﺍﻷﲪﺎﺽ ﺇﱄ ﲪﺾ ﺍﻟﻜﱪﻳﺘﻴﻚ ﺍﻟﺬﻱ ﻳﻬـﺎﺟﻢ‬ ‫ﺍﳊﺪﻳﺪ ﻭﻳﺴﺒﺐ ﻋﻤﻠﻴﺔ ﺍﻟﺼﺪﺃ ‪ .‬ﻣﻌﺪﻝ ﺍﻟﺼﺪﺃ ﻳﺮﺗﺒﻂ ﺑﻌﻮﺍﻣﻞ ﻛﺜﲑﺓ ﻭﻟﻜﻦ ﰲ ﻣﻨﻄﻘﺘﻨﺎ ﺍﻟﺮﻃﻮﺑﺔ ﻭﺩﺭﺟﺔ‬ ‫ﺍﳊﺮﺍﺭﺓ ﻋﻮﺍﻣﻞ ﺭﺋﻴﺴﻴﻪ ﻭﻣﺆﺛﺮﺓ ﺑﺪﺭﺟﺔ ﻛﺒﲑﻩ ﺟﺪﺍ ﰲ ﻣﻌﺪﻻﺕ ﺍﻟﺼﺪﺃ ﻭﻟﺬﻟﻚ ﳚﺐ ﺍﻟﺘﺤﻜﻢ ﰲ ﺗﻠـﻚ‬ ‫ﺍﻟﻌﻮﺍﻣﻞ ﻟﻴﺼﺒﺢ ﻣﻌﺪﻝ ﺍﻟﺼﺪﺃ ﻗﻠﻴﻞ ﲝﻴﺚ ﻻ ﻳﺴﺒﺐ ﻣﺸﻜﻠﺔ ﻛﺒﲑﺓ ﻋﻠﻲ ﺍﳌﻨﺸﺄﺓ ﺍﻟﻌﻘﺎﺭﻳﺔ‪.‬‬ ‫‪١٧٦‬‬


‫‪& ;j 4 **i8 *@ )*+ &7‬‬

‫ﻋﻤﻠﻴﺔ ﻛﻬﺮﻭﻛﻴﻤﺎﺋﻴﺔ ﲢﺪﺙ ﻋﻨﺪ ﺍﻟﺴﻄﺢ ﺍﻟﻔﺎﺻﻞ ﺑﲔ ﺻﻠﺐ ﺍﻟﺘﺴﻠﻴﺢ ﻭﺍﳋﺮﺳﺎﻧﺔ ﰱ ﻭﺟـﻮﺩ ﻋﺎﻣـﻞ‬ ‫ﻣﺆﻛﺴﺪ ) ﺍﻻﻛﺴﺠﲔ( ﻭﺭﻃﻮﺑﺔ ﻭﺗﻴﺎﺭ ﻣﻦ ﺍﻻﻟﻜﺘﺮﻭﻧﻴﺎﺕ ﻳﺴﺮﻯ ﻣﻦ ﻗﻄﺐ ﻣﻮﺟﺐ ﺍﱃ ﻗﻄﺐ ﺳـﺎﻟﺐ‬ ‫ﻭﻭﺳﻂ ﻳﻨﻘﻞ ﺍﻟﺘﻴﺎﺭ ﺍﻟﻜﻬﺮﰉ ﻣﺎﺀ ﺍﻭ ﳏﻠﻮﻝ ﻣﺎﺋﻰ ﺑﺔ ﺍﻣﻼﺡ ﺫﺍﺋﺒﺔ‪ .‬ﻳﺒﺪﺃ ﺍﻟﺼﺪﺃ ﻋﻨﺪ ﺗﻜﺴﺮ ﺍﻟﻄﺒﻘﺔ ﺍﳊﺎﻣﻴﺔ‬ ‫ﳊﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﺫﺍﺕ ﺍﻟﻘﺎﻋﺪﻳﺔ ﺍﻟﻌﺎﻟﻴﺔ ﻭﺍﻟﱴ ﺗﺘﻠﺨﺺ ﰱ ‪-:‬‬ ‫‪ -١‬ﻳﺬﻭﺏ ﺍﳊﺪﻳﺪ ﻣﻦ ﺍﻟﻘﻄﺐ ﺍﳌﻮﺟﺐ ﻋﻠﻰ ﻫﻴﺌﺔ ﺍﻳﻮﻧﺎﺕ ﺍﳊﺪﻳﺪﻭﺯ ‪ (Fe)++‬ﺣﺴﺐ ﺍﻟﺘﻔﺎﻋﻞ‬ ‫‪2 Fe++ + 4e‬‬‫‪ -٢‬ﺗﻨﺘﻘﻞ ﺍﻻﻟﻜﺘﺮﻭﻧﻴﺎﺕ ﺍﳌﺘﻮﻟﺪﺓ ﻣﻦ ﺍﻟﺘﻔﺎﻋﻞ ﺍﻟﺴﺎﺑﻖ ‪ 4e-‬ﻣﻦ ﺍﻟﺴﻴﺦ ﺍﳊﺪﻳﺪ ﺍﱃ ﺍﻟﻘﻄﺐ ﺍﻟﺴﺎﻟﺒﺤﻴﺚ‬ ‫‪2 Fe -‬‬

‫ﺗﺘﻔﺎﻋﻞ ﻣﻊ ﺍﻻﻛﺴﺠﲔ ﻭﺍﳌﺎﺀ ﻣﻜﻮﻧﺔ ﺍﻳﻮﻧﺎﺕ ﺍﳍﻴﺪﺭﻭﻛﺴﻴﻞ ‪ (OH)-‬ﺣﺴﺐ ﺍﻟﺘﻔﺎﻋﻞ‪:‬‬ ‫‪2H2O + O2 + 4e-‬‬

‫‪4 ( OH )-‬‬

‫‪ -٣‬ﻳﺘﻢ ﺍﻟﺘﻔﺎﻋﻞ ﺑﲔ ﺍﻳﻮﻧﺎﺕ ﺍﳊﺪﻳﺪﻭﺯ ﺍﻟﻨﺎﲡﺔ ﻣﻦ ﺍﻟﺘﻔﺎﻋﻞ ﺍﻻﻭﻝ ﻣﻊ ﺍﻳﻮﻧﺎﺕ ﺍﳍﻴﺪﺭﻭﻛﺴﻴﻞ ﺍﻟﻨﺎﲡﺔ ﻣﻦ‬ ‫ﺍﻟﺘﻔﺎﻋﻞ ﺍﻟﺜﺎﱏ‬ ‫‪4 Fe++ + 4 ( OH )-‬‬

‫‪2 Fe ( OH )2‬‬

‫‪ -٤‬ﻳﺘﺄﻛﺴﺪ ﻫﻴﺪﺭﻭﻛﺴﻴﺪ ﺍﳊﺪﻳﺪﻭﺯ ﺍﻟﻨﺎﺗﺞ ﺑﻔﻌﻞ ﺍﻻﻛﺴﺠﲔ ﻭﺍﳌﺎﺀ ﺍﱃ ﺍﻳﺪﺭﻭﻛﺴﻴﺪ ﺍﳊﺪﻳﺪﻳﻚ ﻭﺍﻟﺬﻯ‬ ‫ﻳﺘﺤﻠﻞ ﻣﻜﻮﻧﺎ ﺻﺪﺃ ﺣﺪﻳﺪ ﺍﻟﺘﺴﻠﻴﺢ ﺍﻛﺴﻴﺪ ﺍﳊﺪﻳﺪ‬ ‫‪Fe2O3 . H2O.‬‬

‫‪2 Fe ( OH )3‬‬

‫‪O2‬‬

‫‪+‬‬

‫‪H 2O‬‬

‫‪2 Fe ( OH )2 -‬‬

‫ﻭﻳﻌﺘﱪ ﺃﻛﺴﻴﺪ ﺍﳊﺪﻳﺪ ﺷﺪﻳﺪ ﺍﻻﻣﺘﺼﺎﺹ ﻟﻠﻤﺎﺀ ﻭﺿﻌﻴﻒ ﺍﻻﻟﺘﺼﺎﻕ ﺑﺎﳊﺪﻳﺪ ﻭﻳﺴﻬﻞ ﺍﺯﺍﻟﺘﺔ ﺑﺎﻟـﺬﻭﺑﺎﻥ‬ ‫ﺍﻟﺒﻄﻰﺀ ﺗﺎﺭﻛﺎ ﺳﻄﺢ ﺍﳊﺪﻳﺪ ﻟﻴﺴﻤﺢ ﺑﺘﻜﻮﻥ ﺻﺪﺃ ﺍﳊﺪﻳﺪ‪ .‬ﻫﻴﺪﺭﻭﻛﺴﻴﺪ ﺍﳊﺪﻳﺪ ﺍﻟﻨﺎﺗﺞ ﻳﺰﻳﺪ ﺣﺠﻤﺔ ﻋﻦ‬ ‫ﺣﺠﻢ ﺍﻟﺴﻴﺦ ﺍﻻﺻﻠﻰ ﳑﺎ ﻳﺆﺩﻯ ﺍﱃ ﺍﺟﻬﺎﺩﺍﺕ ﺍﻧﻔﻌﺎﻟﻴﺔ ﺗﺆﺩﻯ ﺍﱃ ﺷﺮﻭﺥ ﺍﻧﻔﺼﺎﻟﻴﺔ ﺣﻮﻝ ﳏﻮﺭ ﺍﻟـﺴﻴﺦ‬ ‫ﻭﻋﻨﺪ ﺯﻳﺎﺩﺓ ﺍﻟﺼﺪﺃ ﺗﺒﺪﺃ ﺍﳋﺮﺳﺎﻧﺔ ﺍﻟﺴﻄﺤﻴﺔ ﰱ ﺍﻟﺴﻘﻮﻁ‪.‬‬

‫‪١٧٧‬‬


‫; ` ‪-:R8U **+ *h‬‬

‫‪ -١‬ﻧﻘﺾ ﺍﻟﻐﻄﺎﺀ ﺍﳋﺮﺳﺎﱏ ﻋﻦ ﺣﺪ ﻣﻌﲔ ﻣﻊ ﻭﺟﻮﺩ ﺍﻟﺮﻃﻮﺑﺔ ﻭﺍﻻﻛﺴﺠﲔ‬ ‫‪ -٢‬ﻓﻘﺪ ﺍﳊﻤﺎﻳﺔ ﺍﻟﺴﻠﺒﻴﺔ ﺍﳌﺘﻮﻓﺮﺓ ﻟﻸﺳﻴﺎﺥ ﺑﻮﺟﻮﺩ ﺍﳋﺮﺳﺎﻧﺔ ﻭﺫﻟﻚ ﺑﻔﻘﺪ ﻗﺎﻋﺪﻳﺔ ﺍﳋﺮﺳﺎﻧﺔ ﺍﶈﻴﻄـﺔ‬ ‫ﺑﺎﻻﺳﻴﺎﺥ ﻭﻧﻘﺺ ﻗﻴﻤﺘﻬﺎ ﺍﱃ ﺍﳊﺪ ﺍﻟﺬﻯ ﻳﻨﺨﻔﺾ ﻓﲕ ﺍﻻﺱ ﺍﳍﻴﺪﺭﻭﺟﻴﲎ )‪ (PH‬ﺍﱃ ﺍﻗﻞ ﻣـﻦ‬ ‫‪ ١٠‬ﺣﻴﺚ ﺗﺼﺒﺢ ﺍﻟﻄﺒﻘﺔ ﺍﳊﺎﻣﻴﺔ ﺍﻟﺴﻠﺒﻴﺔ ﻏﲑ ﻣﺘﺰﻧﺔ ﻭﳛﺪﺙ ﺍﻟﺼﺪﺃ ﻃﺒﻘﺎ ﻟﻠﺘﻔﺎﻋﻼﺕ ﺍﻟﺴﺎﺑﻘﺔ‪.‬‬ ‫ ‪( <1T*n o pk ) &*P k *k l m. $-‬‬

‫‪ -١‬ﺍﻟﺘﺤﻮﻝ ﺍﻟﻜﺮﺑﻮﱏ ﺍﻭ ﺍﻟﻜﱪﻳﱴ ﻟﻠﺨﺮﺳﺎﻧﺔ‪ .‬ﻭﻫﻮ ﻋﺒﺎﺭﺓ ﻋﻦ ﺗﻔﺎﻋﻞ ﺛﺎﱏ ﺍﻛﺴﻴﺪ ﺍﻟﻜﺮﺑﻮﻥ ﺍﻭ ﺛﺎﱏ‬ ‫ﺍﻛﺴﻴﺪ ﺍﻟﻜﱪﻳﺖ ﺍﳌﻮﺟﻮﺩ ﺑﺎﳉﻮ ﻣﻊ ﺍﳌﻮﺍﺩ ﺍﻟﻘﺎﻋﺪﻳﺔ ﺍﳌﻮﺟـﻮﺩﺓ ﺑﺎﳋﺮﺳـﺎﻧﺔ )ﻫﻴﺪﺭﻭﻛـﺴﻴﺪ‬ ‫ﺍﻟﻜﺎﻟﺴﻴﻮﻡ( ﳏﻮﻻ ﺍﺑﺎﻫﺎ ﺍﱃ ﻛﺮﺑﻮﻧﺎﺕ ﺍﻭ ﻛﱪﻳﺘﺎﺕ ﰱ ﻭﺟﻮﺩ ﺍﻟﺮﻃﻮﺑﺔ‪ .‬ﻭﻧﺘﻴﺠﺔ ﻟـﺬﻟﻚ ﺗﻘـﻞ‬ ‫ﻗﺎﻋﺪﻳﺔ ﺍﳋﺮﺳﺎﻧﺔ ﺍﱃ ﺍﻗﻞ ﻣﻦ ﺍﳌﺴﺘﻮﻯ ﺍﳌﻄﻠﻮﺏ ﻟﺘﻮﻓﲑ ﺍﳊﻤﺎﻳﺔ ﺍﻟﺴﻠﺒﻴﺔ ﻟﻸﺳﻴﺎﺥ‪.‬‬ ‫‪ -٢‬ﻭﺟﻮﺩ ﺷﺮﻭﺥ ﺳﻄﺤﻴﺔ ﻋﻠﻰ ﺍﳋﺮﺳﺎﻧﺔ ﻭﺫﻟﻚ ﺍﱃ ﻋﻤﻖ ﻳﺼﻞ ﺍﱃ ﺍﺳﻴﺦ ﺍﻟﺘﺴﻠﻴﺢ‬ ‫‪ -٣‬ﺗﻌﺮﺽ ﺍﻟﻌﻀﻮ ﺍﳋﺮﺳﺎﱏ ﺍﱃ ﺍﲞﺮﺓ ﺍﻭ ﳏﺎﻟﻴﻞ ﺣﺎﻣﻀﻴﺔ‪.‬‬ ‫‪ -٤‬ﻭﺟﻮﺩ ﺍﻟﻜﻠﻮﺭﻳﺪﺍﺕ ﻭﺯﻳﺎﺩﺓ ﳏﺘﻮﺍﻫﺎﺳﻮﺍﺀ ﰱ ﺍﳋﻠﻄﺔ ﺍﳋﺮﺳﺎﻧﻴﺔ ﺍﺻﻼ ﺍﻭ ﺗﻐﻠﻐﻠﻬﺎ ﰱ ﺍﳋﺮﺳـﺎﻧﺔ‬ ‫ﻣﻦ ﺍﻟﻮﺳﻂ ﺍﶈﻴﻂ‪ .‬ﻭﻭﺟﻮﺩ ﺍﻟﻜﻠﻮﺭﻳﺪﺍﺕ ﺍﻯ ﻛﺎﻥ ﻣﺼﺪﺭﻫﺎ ﰱ ﺍﳋﺮﺳﺎﻧﺔ ﻳﺆﺩﻯ ﺍﱃ ﺗﻨـﺸﻴﻂ‬ ‫ﻋﻤﻠﻴﺔ ﺍﻟﺼﺪﺃ ﺑﺎﻟﺮﻏﻢ ﻣﻦ ﺍﻥ ﻗﺎﻋﺪﻳﺔ ﺍﳋﺮﺳﺎﻧﺔ ﻣﺮﺗﻔﻌﺔ‪ .‬ﻭﺍﳉﺪﻳﺮ ﺑﺎﻟﺬﻛﺮ ﺍﻥ ﺍﻟﻜﻠﻮﺭﻳﺪﺍﺕ ﺍﻟﱴ‬ ‫ﺗﺘﻐﻠﻐﻞ ﺍﱃ ﺍﳋﺮﺳﺎﻧﺔ ﺍﺷﺪ ﻓﺎﻋﻠﻴﺔ ﰱ ﺍﻟﺘﺄﺛﲑ ﻋﻠﻰ ﺻﻠﺐ ﺍﻟﺘﺴﻠﻴﺢ ﻣﻦ ﺍﻟﻜﻠﻮﺭﻳﺪﺍﺕ ﺍﳌﻮﺟﻮﺩﺓ ﰱ‬ ‫ﺍﳋﻠﻄﺔ ﺣﻴﺚ ﺍﻻﻭﱃ ﺗﻜﻮﻥ ﺣﺮﺓ ﺍﳊﺮﻛﺔ ﰱ ﺍﳌﺎﺀ ﺍﻣﺎ ﺍﻟﺜﺎﻧﻴﺔ ﺗﻜﻮﻥ ﻣﻘﻴﺪﺓ ﺍﳊﺮﻛﺔ‪.‬‬ ‫*******‬

‫‪١٧٨‬‬


‫ ‬ ‫ ‬ ‫‪ 1 – 9‬‬

‫ﺍﳌﻌﺎﳉﺔ ﺍﳊﺮﺍﺭﻳﺔ ﻫﻲ ﺭﻓﻊ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﳌﻌﺪﻥ ﺃﻭ ﺍﻟﺴﺒﻴﻜﺔ ﺇﱃ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﻣﻌﻴﻨﺔ ﻭﺗﺜﺒﻴـﺖ ﺩﺭﺟـﺔ‬ ‫ﺍﳊﺮﺍﺭﺓ ﻟﻔﺘﺮﺓ ﺯﻣﻨﻴﺔ ﻣﻼﺋﻤﺔ ﻭﻣﻦ ﰎ ﺍﻟﺘﱪﻳﺪ ﲟﻌﺪﻝ ﺗﱪﻳﺪ ﻣﻌﲔ ﻓﻬﺬﻩ ﺍﻟﻌﻮﺍﻣﻞ ﺍﻟﺜﻼﺛﺔ ‪-:‬‬ ‫‪M@c‬‬

‫…‪@ @Næ†È½a@bèîÛg@å‚í@Ûa@ñ‰aŠ§a@òu‰‬‬

‫‪M@l‬‬

‫‹‪N@ñ‰aŠ§a@òu‰…@oîjrm@åß‬‬

‫‪M@p‬‬

‫‪N@†ínÛa@Þ†Èß‬‬

‫ﳍﺎ ﺗﺄﺛﲑ ﺑﺎﻟﻎ ﻋﻠﻰ ﺍﳋﻮﺍﺹ ﺍﳌﺮﺍﺩ ﲢﻘﻴﻘﻬﺎ ﻣﻦ ﺍﳌﻌﺎﳉﺔ ﺍﳊﺮﺍﺭﻳﺔ ﻟﺬﺍ ﻳﻨﺒﻐﻲ ﺃﻥ ﲢﺪﺩ ﻫﺬﻩ ﺍﻟﻌﻮﺍﻣﻞ ﺑﺼﻮﺭﺓ‬ ‫ﺩﻗﻴﻘﺔ ﻭﺇﻥ ﺃﻱ ﺧﻄﺎ ﰲ ﲢﺪﻳﺪ ﻫﺬﻩ ﺍﻟﻌﻮﺍﻣﻞ ﻳﺆﺩﻱ ﺇﱃ ﻋﺪﻡ ﲢﻘﻴﻖ ﺍﳋﻮﺍﺹ ﺍﳌﻄﻠﻮﺑﺔ ﻭﺍﻟﻐﺎﻳﺔ ﺍﳌﺘﻮﺧﺎﻩ ﻣﻦ‬ ‫ﺍﳌﻌﺎﳉﺔ ﺍﳊﺮﺍﺭﻳﺔ ‪.‬‬ ‫‪ 2- 9‬‬

‫‪‬ﺪﻑ ﺍﳌﻌﺎﳉﺔ ﺍﳊﺮﺍﺭﻳﺔ ﻟﻠﻤﻌﺎﺩﻥ ﻭﺍﻟﺴﺒﺎﺋﻚ ﺇﱃ ‪-:‬‬ ‫• ﺇﻛﺴﺎﺏ ﺍﳌﻌﺪﻥ ﺍﳋﻮﺍﺹ ﺍﻟﻨﻬﺎﺋﻴﺔ ﺍﳌﻄﻠﻮﺑﺔ ﻭﻳﺘﻢ ﺫﻟﻚ ﻋﻠﻰ ﻗﻄﻊ ﺍﻟﻌﻤﻞ ﺍﳌﻨﺘﻬﻴﺔ ﻣﺜﻞ ) ﺍﻟﺘﺼﻠﻴﺪ‬ ‫‪ ،‬ﺍﻟﺘﺼﻠﻴﺪ ﺍﻟﻐﻼﰲ ( ﻭﻣﻦ ﺍﳌﻤﻜﻦ ﺃﻥ ﺗﺘﺒﻊ ﻫﺬﻩ ﺍﻟﻌﻤﻠﻴﺔ ﻋﻤﻠﻴﺎﺕ ﺗﺸﻄﻴﺐ ‪‬ﺎﺋﻴﺔ ﻹﺯﺍﻟﺔ ﺑﻌـﺾ‬ ‫ﺗﺸﻮﻫﺎﺕ ﺍﳌﻌﺎﳉﺔ ﺍﳊﺮﺍﺭﻳﺔ‪.‬‬ ‫• ﲢﺴﲔ ﺍﳋﻮﺍﺹ ﺍﻟﺘﺸﻐﻴﻠﻴﺔ ﻭﺍﻟﺘﺸﻜﻴﻠﻴﺔ ﻟﻠﻤﻌﺪﻥ ﻭﺫﻟﻚ ﺑﺰﻳﺎﺩﺓ ﻟﺪﻭﻧﺘﻪ ﳑﺎ ﻳﺴﻤﺢ ﺑﺰﻳﺎﺩﺓ ﺇﻧﺘﺎﺟﻴﺔ‬ ‫ﺍﻟﺘﺸﻐﻴﻞ ﻭﻋﺪﻡ ﺣﺪﻭﺙ ﺗﺸﻮﻫﺎﺕ ﺃﺛﻨﺎﺀ ﻋﻤﻠﻴﺎﺕ ﺍﻟﺘﺸﻜﻴﻞ ﻣﺜﻞ ﺍﻟﺴﺤﺐ ﻭﺍﻟﻜﺒﺲ ﻭﻣﻦ ﺍﳌﻌﺘﺎﺩ‬ ‫ﺃﻥ ﻳﺘﻢ ﺫﻟﻚ ﻋﻠﻰ ﺍﳌﻮﺍﺩ ﺍﳋﺎﻡ ﻭﻧﺼﻒ ﺍﳌﺼﻨﻌﺔ ﻗﺒﻞ ﻭﺃﺛﻨﺎﺀ ﻋﻤﻠﻴﺎﺕ ﺍﻟﺘﺸﻐﻴﻞ ﻭﺍﻟﺘﺸﻜﻴﻞ ‪.‬‬ ‫‪! "# " $% & ' ()* 3 -9‬‬

‫ﺃ‪ -‬ﺍﻟﺘﺨﻤﲑ ﻫﻰ ﺍﳌﻌﺎﳉﺔ ﺍﳊﺮﺍﺭﻳﺔ ﺍﻟﱴ ﺗﺰﻳﺪ ﻣﻦ ﻣﺮﻭﻧﺔ ﻭﻟﺪﻭﻧﺔ ﺍﻟﺼﻠﺐ‬ ‫ﺏ‪ -‬ﺍﻟﺘﺼﻠﻴﺪ ﻫﻰ ﺍﳌﻌﺎﳉﺔ ﺍﳊﺮﺍﺭﻳﺔ ﺍﻟﱴ ﺗﺰﻳﺪ ﻣﻦ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺼﻠﺐ ﻟﻠﺨﺪﺵ ﻭﺍﻟﺘﺂﻛﻞ‬ ‫‪١٧٩‬‬


‫ﺕ‪ -‬ﺍﳌﺮﺍﺟﻌﺔ ﻫﻰ ﺍﳌﻌﺎﳉﺔ ﺍﳊﺮﺍﺭﻳﺔ ﺍﻟﱴ ﺗﻘﻠﻞ ﻣﻦ ﺍﳍﺸﺎﺷﻴﺔ ﺍﳌﻮﺟﻮﺩﺓ ﰲ ﺍﻟـﺼﻠﺐ ﺑﻌـﺪ ﻋﻤﻠﻴـﺔ‬ ‫ﺍﻟﺘﺼﻠﻴﺪ‪.‬‬ ‫ﺙ‪ -‬ﺍﳌﻌﺎﺩﻟﺔ ﻫﻰ ﺍﳌﻌﺎﳉﺔ ﺍﳊﺮﺍﺭﻳﺔ ﺍﻟﱴ ﺗﻌﻤﻞ ﻋﻠﻰ ﺗﻨﻈﻴﻢ ﺍﻟﺘﺮﻛﻴﺐ ﺍﻟﺒﻴﲏ ﻟﻠﻤﻌﺪﻥ ﻧﺘﻴﺠﺔ ﻟـﺘﻐﲑﻩ ﰲ‬ ‫ﻋﻤﻠﻴﺎﺕ ﺍﻟﺘﺸﻜﻴﻞ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ‪.‬‬ ‫‪Hardening ( - ) 4 -9‬‬

‫ﻫﻨﺎﻙ ﺃﺭﺑﻌﺔ ﺃﻧﻮﺍﻉ ﻣﻦ ﺍﳌﻌﺎﳉﺎﺕ ﺍﳊﺮﺍﺭﻳﺔ ﺍﻷﺳﺎﺳﻴﺔ ﺍﻟﺸﺎﺋﻌﺔ ﺍﻟﱵ ﲡﺮﻱ ﻋﻠﻰ ﺍﻟﺼﻠﺐ ﻟﻐـﺮﺽ ﺗﻐـﻴﲑ‬ ‫ﺧﻮﺍﺻﻪ ﺍﳌﻴﻜﺎﻧﻴﻜﻴﺔ ﻭﻣﻦ ﺍﻣﺜﻠﺘﻬﺎ ﺍﻟﺘﺼﻠﻴﺪ‪-:‬‬ ‫‪@ @@†îÜ–nÛa@òîÜàÇ@åß@Ò†a@@Q@MT@MY‬‬ ‫‪‬ﺪﻑ ﻫﺬﻩ ﺍﻟﻌﻤﻠﻴﺔ ﺇﱃ ﺯﻳﺎﺩﺓ ﺻﻼﺩﺓ ﺍﻟﻔﻮﻻﺫ ﻭﺭﻓﻊ ﻣﻘﺎﻭﻣﺘﻪ ﻹﺟﻬﺎﺩ ﺍﻟﺸﺪ ﻭﻣﻘﺎﻭﻣﺔ ﺍﻟﺘﺂﻛﻞ ﺑﺎﻻﺣﺘﻜﺎﻙ‬ ‫ﻭﻳﺘﻢ ﺍﻟﺘﺼﻠﻴﺪ ﺇﻣﺎ ﺑﺎﻟﺘﺸﻜﻴﻞ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﺃﻭ ﺑﺎﳌﻌﺎﳉﺎﺕ ﺍﳊﺮﺍﺭﻳﺔ‪.‬‬ ‫‪@ @Z@†îÜ–nÛa@bîuìÛìäØm@R@–@T@–@Y‬‬ ‫ﺍﳊﺪﻳﺪ ﻣﻦ ﺍﳌﻌﺎﺩﻥ ﺍﳌﺘﺂﺻﻠﺔ ﻓﻔﻲ ﺩﺭﺟﺎﺕ ﺍﳊﺮﺍﺭﺓ ﺍﻷﻋﻠﻰ ﻳﻜﻮﻥ ﻋﺒﺎﺭﺓ ﻋﻦ ﺃﻭﺳـﺘﻨﻴﺖ ﺫﻱ ﺍﻟـﺸﺒﻜﺔ‬ ‫ﺍﳌﻜﻌﺒﻴﺔ ﺍﳌﺘﻤﺮﻛﺰﺓ ﺍﻟﻮﺟﻪ ﻭﺍﻟﱵ ﺗﺬﻳﺐ ﺍﻟﻜﺮﺑﻮﻥ‪.‬‬ ‫ﻋﻨﺪ ﺗﱪﻳﺪ ﺍﳊﺪﻳﺪ ﺗﱪﻳﺪﺃ ﺑﻄﻴﺌﹰﺎ ﻳﺘﺤﻮﻝ ﺇﱃ ﺍﻟﻔﺮﻳﺖ ﺫﻱ ﺍﻟﺸﺒﻜﺔ ﺍﳌﻜﻌﺒﻴﺔ ﺍﳌﺘﻤﺮﻛﺰﺓ ﺍﳉﺴﻢ ﺍﻟﱵ ﻻ ﺗﺬﻳﺐ‬ ‫ﺍﻟﻜﺮﺑﻮﻥ‪.‬‬ ‫ﻋﻨﺪ ﺍﻟﺘﱪﻳﺪ ﺍﻟﺴﺮﻳﻊ ﺍﻟﻔﺠﺎﺋﻲ ﻭﺳﺮﻋﺔ ﺍﻟﺘﺤﻮﻝ ﻣﻦ ﺍﻟﺸﺒﻜﺔ ﺍﳌﻜﻌﺒﻴﺔ ﺍﳌﺘﻤﺮﻛـﺰﺓ ﺍﻟﻮﺟـﻪ ﺇﱃ ﺍﻟـﺸﺒﻜﺔ‬ ‫ﺍﳌﻜﻌﺒﻴﺔ ﺍﳌﺘﻤﺮﻛﺰﺓ ﺍﳉﺴﻢ ﻻ ﲡﺪ ﺫﺭﺍﺕ ﺍﻟﻜﺮﺑﻮﻥ ﻓﺮﺻﺘﻬﺎ ﻟﻼﻧﻄﺮﺍﺩ ﺧﺎﺭﺝ ﺣﺪﻭﺩ ﺍﻟﺬﺭﺍﺕ ﻓﺘﻨﺤـﺸﺮ‬ ‫ﺩﺍﺧﻞ ﺍﻟﺬﺭﺍﺕ ﻣﻜﻮﻧﺔ ﺑﻨﻴﺔ ﺻﻠﺪﺓ ﻭﻗﺼﻔﺔ ﺗﺴﻤﻰ ﺍﳌﺮﺗﱰﻳﺖ ﻭﻻ ﳛﺪﺙ ﺫﻟـﻚ ﺇﻻ ﺑﺎﻟﺘﱪﻳـﺪ ﺍﳌﻔـﺎﺟﺊ‬ ‫ﺍﻟﺴﺮﻳﻊ‪.‬‬ ‫‪@ @Z@†îÜ–nÛa@òîÜàÈÛ@òîäÐÛa@þa@S@–@T@–@Y‬‬ ‫‪ .١‬ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﻟﺘﺼﻠﻴﺪ‬

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‫‪ .٢‬ﻭﺟﻮﺏ ﲡﺎﻧﺲ ﺍﻷﻭﺳﺘﻨﻴﺖ ﻗﺒﻞ ﺍﻟﺘﱪﻳﺪ‪ .‬ﻟﻀﻤﺎﻥ ﺍﻟﺘﻮﺯﻳﻊ ﺍﳌﻨﺘﻈﻢ ﻟﺬﺭﺍﺕ ﺍﻟﻜﺮﺑﻮﻥ ﺩﺍﺧﻞ‬ ‫ﺣﺒﻴﺒﺎﺕ ﺍﻷﻭﺳﺘﻨﻴﺖ ﺣﱴ ﻻ ﳓﺼﻞ ﻋﻠﻰ ﺻﻠﺐ ﺫﻱ ﺻﻼﺩﺍﺕ ﻣﺘﺒﺎﻳﻨﺔ ‪ ،‬ﻭﲢﺴﺐ ﰲ ﺍﻟﻐﺎﻟﺐ‬ ‫ﻟﻜﻞ ‪ ٢,٥‬ﺳﻢ ﻟﻠﺴﻤﻚ ﺃﻭ ﺍﻟﻘﻄﺮ‪.‬‬ ‫‪ .٣‬ﺍﻻﻧﺘﻘﺎﻝ ﺍﳊﺮﺍﺭﻱ ﺃﺛﻨﺎﺀ ﻋﻤﻠﻴﺔ ﺍﻟﺘﺼﻠﻴﺪ‪ .‬ﺻﻼﺩﺓ ﻗﻄﻌﺔ ﺍﻟﻌﻤﻞ ﺗﻌﺘﻤﺪ ﻋﻠﻰ ﺳﺮﻋﺔ ﺍﻟﺘﱪﻳﺪ ﻓﻴﺠﺐ‬ ‫ﺍﻟﺘﻘﻠﻴﺐ ﺍﻟﺴﺮﻳﻊ ﻭﺍﳌﺴﺘﻤﺮ ﺃﺛﻨﺎﺀ ﺍﻟﺘﺼﻠﻴﺪ ﻟﻠﺘﺨﻠﺺ ﻣﻦ ﺍﻟﻄﺒﻘﺔ ﺍﻟﻐﺎﺯﻳﺔﺍﶈﻴﻄﺔ ﻟﻘﻄﻌﺔ ﺍﻟﻌﻤﻞ ‪.‬‬ ‫‪ .٤‬ﻧﻮﻉ ﻭﺳﻴﻂ ﺍﻟﺘﱪﻳﺪ‪ .‬ﳚﺐ ﺃﻥ ﻳﺘﻤﺘﻊ ﻭﺳﻴﻂ ﺍﻟﺘﱪﻳﺪ ﻭﻟﻮ ﺑﺸﻜﻞ ﻧﺴﱯ ﲟﻴﺰﺓ ﺍﺳﺘﻴﻌﺎﺏ ﻛﻤﻴﺔ‬ ‫ﺍﳊﺮﺍﺭﺓ ﰲ ﺍﻟﻠﺤﻈﺎﺕ ﺍﻷﻭﱃ ﻟﻌﻤﻠﻴﺔ ﺍﻟﺘﱪﻳﺪ ﻟﻀﻤﺎﻥ ﺗﻜﻮﻥ ﺍﳌﺮﺗﱰﻳﺖ ﰒ ﲟﻌﺪﻝ ﺗﱪﻳﺪ ﻣﻨﺨﻔﺾ‬ ‫ﳌﻨﻊ ﺍﻟﺘﺸﻮﻩ ﺍﻟﺬﻱ ﻗﺪ ﳛﺪﺙ ﰲ ﻣﻨﻄﻘﺔ ﺍﻟﻌﻤﻞ ‪ ،‬ﻭﻣﻦ ﻭﺳﺎﺋﻂ ﺍﻟﺘﱪﻳﺪ ﺍﳌﺴﺘﺨﺪﻣﺔ ﺍﳌﺎﺀ ‪ ،‬ﺍﻟﺰﻳﺖ‪.‬‬ ‫‪ .٥‬ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﻟﻮﺳﻴﻂ‪ .‬ﻛﻠﻤﺎ ﺯﺍﺩﺕ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﻭﺳﻴﻂ ﺍﻟﺘﱪﻳﺪ ﻗﻞ ﻣﻌﺪﻝ ﺍﻟﺘﱪﻳﺪ ‪ ،‬ﻭﻟﻀﻤﺎﻥ‬ ‫ﺫﻟﻚ ﳚﺐ ﺍﺳﺘﺨﺪﺍﻡ ﻛﻤﻴﺎﺕ ﻛﺒﲑﺓ ﻣﻦ ﻭﺳﻴﻂ ﺍﻟﺘﱪﻳﺪ ﻭﺇﺣﺪﺍﺙ ﺣﺮﻛﺎﺕ ﺩﻭﺍﻣﻴﺔ ﺃﺛﻨﺎﺀ ﺗﻘﻠﻴﺐ‬ ‫ﻗﻄﻊ ﺍﻟﻌﻤﻞ ‪.‬‬ ‫‪ .٦‬ﺳﻄﺢ ﻗﻄﻌﺔ ﺍﻟﻌﻤﻞ ﺍﳌﺼﻠﺪﺓ‪ .‬ﺗﺘﻜﻮﻥ ﻋﻠﻰ ﺳﻄﺢ ﻗﻄﻌﺔ ﺍﻟﻌﻤﻞ ﻃﺒﻘﺔ ﻣﻦ ﺍﻷﻭﻛﺴﻴﺪ ﻧﺘﻴﺠﺔ ﲞﺎﺭ‬ ‫ﺍﳌﺎﺀ ﻭﻫﺬﻩ ﺍﻟﻄﺒﻘﺔ ﺗﻘﻠﻞ ﻣﻌﺪﻝ ﺍﻟﺘﱪﻳﺪ ﻭﻳﺘﻐﻠﺐ ﻋﻠﻰ ﺫﻟﻚ ﺑﻌﺪﺓ ﻃﺮﻕ ﻣﻨﻬﺎ ‪-:‬‬ ‫• ﺍﻟﻄﻼﺀ ﺑﺎﻟﻨﺤﺎﺱ‬ ‫• ﺍﺳﺘﺨﺪﺍﻡ ﺟﻮ ﺧﺎﻣﻞ ﺩﺍﺧﻞ ﻓﺮﻥ ﺍﻟﺘﺴﺨﲔ‬ ‫• ﺍﻟﺘﺴﺨﲔ ﰲ ﲪﺎﻣﺎﺕ ﺍﻷﻣﻼﺡ ﺍﳌﻨﺼﻬﺮﺓ‬ ‫• ﺇﺣﺎﻃﺔ ﺍﳉﺰﺀ ﺑﱪﺍﺩﺓ ﺣﺪﻳﺪ ﺍﻟﺰﻫﺮ‬ ‫‪@ @†îÜ–nÛa@òîÜàÇ@õbäqc@bèqë†y@åØà½a@lìîÈÛa@T@–@T@–@Y‬‬ ‫‪ .١‬ﺍﳔﻔﺎﺽ ﺍﻟﺼﻼﺩﺓ ﻭﲢﺪﺙ ﻧﺘﻴﺠﺔ ﻋﺪﻡ ﺍﻟﺘﺴﺨﲔ ﺇﱃ ﺩﺭﺟﺔ ﺍﳊﺮﺍﺭﺓ ﺍﻟﻼﺯﻣﺔ ﺃﻭ ﻋﺪﻡ‬ ‫ﺍﻟﺘﱪﻳﺪ ﺑﺎﻟﺴﺮﻋﺔ ﺍﻟﻜﺎﻓﻴﺔ ‪.‬‬ ‫‪ .٢‬ﺍﻟﺼﻼﺩﺓ ﺍﳌﺘﻔﺎﻭﺗﺔ ﻭﳛﺪﺙ ﻟﻌﺪﻡ ﲡﺎﻧﺲ ﺍﻷﻭﺗﻨﺴﻴﺖ ﰲ ﺍﻟﺒﻨﻴﺔ ‪.‬‬ ‫‪ .٣‬ﺗﺄﻛﺴﺪ ﺍﻟﺴﻄﺢ ﻭﺍﺣﺘﺮﺍﻕ ﺍﻟﻜﺮﺑﻮﻥ ﻓﻴﻪ ﻭﳛﺪﺙ ﻧﺘﻴﺠﺔ ﻋﺪﻡ ﻋﺰﻝ ﺳﻄﺢ ﺍﻟﻘﻄﻌﺔ‬ ‫ﺍﳌﺼﻠﺪﺓ ‪.‬‬ ‫‪ .٤‬ﺗﺸﻘﻖ ﺍﳌﺸﻐﻮﻻﺕ ﻭﺍﻋﻮﺟﺎﺟﻬﺎ ﻭﻫﻮ ﻣﻦ ﺃﺧﻄﺮ ﺍﻟﻌﻴﻮﺏ ﻭﳛﺪﺙ ﻧﺘﻴﺠﺔ ﺍﻹﺟﻬﺎﺩﺍﺕ‬ ‫ﺍﻟﻜﺒﲑﺓ ﺍﻟﱵ ﲢﺪﺙ ﺃﺛﻨﺎﺀ ﻋﻤﻠﻴﺔ ﺍﻟﺘﺼﻠﻴﺪ ﻟﺬﻟﻚ ﳚﺐ ﺗﺪﻭﻳﺮ ﺃﺭﻛﺎﻥ ﺍﻟﻘﻄﻊ ﺍﳌﺼﻠﺪﺓ‬ ‫ﻭﺍﻟﺘﺪﺭﺝ ﰲ ﻣﻘﺎﻃﻊ ﺍﳌﺸﻐﻮﻻﺕ ‪.‬‬ ‫‪١٨١‬‬


‫‪@ @Z@ïzĐÛa@†îÜ–nÛa@U@–@T@–@Y‬‬ ‫ﻳﻜﻮﻥ ﺍﻟﺘﺼﻠﻴﺪ ﺍﻟﺴﻄﺤﻲ ﻋﻠﻰ ﺳﻄﺢ ﻗﻄﻊ ﺍﻟﻌﻤﻞ ﻓﻘﻂ ﻭﺫﻟﻚ ﻟﻠﺤﺼﻮﻝ ﻋﻠﻰ ﺳﻄﺢ ﻳﻘـﺎﻭﻡ ﺍﻟﺘﺂﻛـﻞ‬ ‫ﺑﺎﻻﺣﺘﻜﺎﻙ ﻣﻊ ﺍﻻﺣﺘﻔﺎﻅ ﺑﻘﻠﺐ ﻟﲔ ﻳﻘﺎﻭﻡ ﺍﻟﺼﺪﻣﺎﺕ ﻭﻳﺘﻢ ﺍﻟﺘﺼﻠﻴﺪ ﺍﻟﺴﻄﺤﻲ ﺑﺸﻜﻞ ﻋﺎﻡ ﻋﻠﻰ ﺍﻟﺼﻠﺐ‬ ‫ﻣﻨﺨﻔﺾ ﺍﻟﻜﺮﺑﻮﻥ ﻭﺫﻟﻚ ﺑﻌﺪﺓ ﻃﺮﻕ ‪-:‬‬ ‫‪ ١ - 5 – 4 – 9‬ﺍﻟﺘﺼﻠﻴﺪ ﺑﺎﻟﻜﺮﺑﻨﺔ ‪Carburizing‬‬

‫ﻭﺗﻌﺘﻤﺪ ﻋﻠﻰ ﺗﻐﻠﻐﻞ ﺍﻟﻜﺮﺑﻮﻥ ﻭﺍﻧﺘﺸﺎﺭﻩ ﻋﻠﻰ ﺳﻄﺢ ﺍﻟﺼﻠﺐ ﻣﻜﻮﻧﹰﺎ ﻣﺮﻛﺐ ﻛﺮﺑﻴﺪ ﺍﳊﺪﻳﺪ ) ‪( Fe3C‬‬ ‫ﺑﻌﺪ ﺗﺴﺨﻴﻨﻪ ﻟﺪﺭﺟﺔ ﺗﻜﻮﻥ ﺍﻷﻭﺗﻨﺴﻴﺖ ‪ ،‬ﻭﺍﻟﻜﺮﺑﻮﻥ ﻳﻜﻮﻥ ﳏﺎﻃﹰﺎ ﺑﻘﻄﻌﺔ ﺍﻟﻌﻤﻞ ﻋﻠﻰ ﺷﻜﻞ ﺻﻠﺐ ﺃﻭ‬ ‫ﺳﺎﺋﻞ ﺃﻭ ﻏﺎﺯ ‪.‬‬ ‫ﺃ – ﺍﻟﻜﺮﺑﻨﺔ ﰲ ﻭﺳﻂ ﺻﻠﺐ‬ ‫ﺗﻮﺿﻊ ﺍﻟﻌﻴﻨﺔ ﰲ ﺻﻨﺎﺩﻳﻖ ﻭﺗﻜﻮﻥ ﳏﺎﻃﺔ ﺑﺎﳌﺎﺩﺓ ﺍﻟﻜﺮﺑﻮﻧﻴﺔ ﻣﺜﻞ ﻓﺤﻢ ﺍﳋﺸﺐ ﺃﻭ ﺍﻟﻔﺤﻢ ﺍﳊﻴﻮﺍﱐ ﺃﻭ ﻓﺤﻢ‬ ‫ﺍﻟﻌﻈﺎﻡ ﺃﻭ ﺍﳉﻠﺪ ﺍﳊﻴﻮﺍﱐ ﻭﺗﻮﺿﻊ ﻋﻠﻰ ﻣﺴﺎﻓﺎﺕ ‪ ٥٠‬ﻣﻢ ﻭﺗﻀﺎﻑ ﻣـﺎﺩﺓ ﻣﻨـﺸﻄﺔ ﻣﺜـﻞ ﻛﺮﺑﻮﻧـﺎﺕ‬ ‫ﺍﻟﺼﻮﺩﻳﻮﻡ ﺃﻭ ﻛﺮﺑﻮﻧﺎﺕ ﺍﻟﺒﺎﺭﻳﻮﻡ ﻭﳛﻜﻢ ﻏﻠﻖ ﺍﻟﺼﻨﺪﻭﻕ ﲝﺸﻮ ﺍﲰﻨﱵ ﻣﺎﻧﻊ ﻣﻦ ﺍﻟﺘﺴﺮﺏ ﻭﻳﺴﺨﻦ ﺑﺒﻂﺀ‬ ‫ﺣﱴ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﻟﻜﺮﺑﻨﺔ ‪ oc 950 – oc 900‬ﻭﳛﻔﻆ ﻋﻨﺪ ﻫﺬﻩ ﺍﻟﺪﺭﺟﺔ ﳌﺪﺓ ﺗـﺼﻞ ﺇﱃ ﲬـﺲ‬ ‫ﺳﺎﻋﺎﺕ ﺗﺒﻌﹰﺎ ﻟﺴﻤﻚ ﺍﻟﻄﺒﻘﺔ ﺍﳌﻄﻠﻮﺑﺔ‬ ‫ﺏ – ﺍﻟﻜﺮﺑﻨﺔ ﰲ ﻭﺳﻂ ﺳﺎﺋﻞ‬ ‫ﺗﺘﻢ ﰲ ﲪﺎﻣﺎﺕ ﻣﻨﺼﻬﺮﺓ ﲢﺘﻮﻱ ﻋﻠﻰ ‪ %٥٠ - %٢٠‬ﺳﻴﺎﻧﻴﺪ ﺍﻟﺼﻮﺩﻳﻮﻡ ﻣﻊ ﻛﺮﺑﻮﻧﺎﺕ ﺍﻟـﺼﻮﺩﻳﻮﻡ‬ ‫ﺑﻨﺴﺒﺔ ‪ %٤٠‬ﰒ ﻳﻀﺎﻑ ﻛﻠﻮﺭﻳﺪ ﺍﻟﺼﻮﺩﻳﻮﻡ ﺃﻭ ﺍﻟﺒﺎﺭﻳﻮﻡ ﻭﻳﺴﺨﻦ ﻫﺬﺍ ﺍﳋﻠﻴﻂ ﺍﻟﻐﲏ ﺑﺎﻟﺴﻴﺎﻧﻴﺪ ﰲ ﺑﻮﺍﺗﻖ‬ ‫ﻣﻐﻠﻔﺔ ﺑﺎﻷﻟﻮﻣﻨﻴﻮﻡ ﺣﱴ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ‪ ، 950oc – 870oc‬ﻭﻳﻐﻤﺮ ﺍﳌﻨﺘﺞ ﺍﳌﻮﺿﻮﻉ ﰲ ﺳـﻼﻝ ﻣـﻦ‬ ‫ﺍﻟﺴﻠﻚ ﻟﻔﺘﺮﺍﺕ ﺗﺘﺮﺍﻭﺡ ﻣﻦ ﲬﺲ ﺩﻗﺎﺋﻖ ﻭﺣﱴ ﺳﺎﻋﺔ ﻭﺫﻟﻚ ﺣﺴﺐ ﺍﻟﻄﺒﻘﺔ ﺍﳌﻄﻠﻮﺑﺔ ﻭﻣﻦ ﳑﻴﺰﺍﺕ ﻫﺬﻩ‬ ‫ﺍﻟﻄﺮﻳﻘﺔ ﻧﻈﺎﻓﺔ ﺳﻄﺢ ﺍﳌﺸﻐﻮﻻﺕ ﻭﺩﻗﺔ ﺍﻟﺘﺤﻜﻢ ﰲ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﳊﻤﺎﻡ ﺍﳌﻨﺼﻬﺮ ﻣﻊ ﺇﻣﻜﺎﻧﻴـﺔ ﺗﱪﻳـﺪ‬ ‫ﺍﻟﺴﻠﺔ ﺍﳊﺎﻭﻳﺔ ﻟﻠﻤﻨﺘﺞ ﺗﱪﻳﺪﹰﺍ ﻓﺠﺎﺋﻴﹰﺎ ﻭﺗﺴﺘﺨﺪﻡ ﻫﺬﻩ ﺍﻟﻄﺮﻳﻘﺔ ﻹﻧﺘﺎﺝ ﻃﺒﻘﺔ ﺭﻗﻴﻘﺔ ﻋﻠﻰ ﺍﻟﺴﻄﺢ ﺑـﺴﻤﻚ‬ ‫‪ ٠,٢٥ – ٠,١‬ﻣﻢ‬

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‫ﺝ – ﺍﻟﻜﺮﺑﻨﺔ ﰲ ﻭﺳﻂ ﻏﺎﺯﻱ‬ ‫ﲡﺮﻱ ﻋﻤﻠﻴﺎﺕ ﺍﻟﻜﺮﺑﻨﺔ ﺍﻟﻐﺎﺯﻳﺔ ﰲ ﺍﻷﻓﺮﺍﻥ ﺫﺍﺕ ﺍﻹﻧﺘﺎﺝ ﺍﳌﺘﻘﻄﻊ ﻭﺍﻷﻓﺮﺍﻥ ﺍﻹﻧﺘﺎﺟﻴﺔ ﻭﻓﻴﻬـﺎ ﺗـﺴﺨﻦ‬ ‫ﺍﳌﻨﺘﺠﺎﺕ ﺣﱴ ‪ oc 900‬ﳌﺪﺓ ﺛﻼﺙ ﺃﻭ ﺃﺭﺑﻊ ﺳﺎﻋﺎﺕ ﰲ ﺟﻮ ﳛﺘﻮﻱ ﻋﻠﻰ ﺍﻟﻜﺮﺑﻮﻥ ﻣﺜﻞ ﺍﳌﻴﺜﺎﻥ ‪CH4‬‬ ‫ﺃﻭ ﺍﻟﱪﻭﺑﺎﻥ ‪ C3H8‬ﺣﻴﺚ ﻳﻨﺒﻐﻲ ﺃﻥ ﺗﻜﻮﻥ ﻋﺎﻟﻴﺔ ﺍﻟﻨﻘﺎﻭﺓ ﻟﺘﻔﺎﺩﻱ ﺍﻟﺘﺮﺳﻴﺐ ﻭﺍﻟﺬﻱ ﻳﻌﻴﻖ ﻋﻤﻠﻴﺔ ﺍﻟﻜﺮﺑﻨﺔ‬ ‫‪.‬‬ ‫‪@ @@Nitriding@ñ…äÛbi@†îÜ–nÛa@@RM@UM@T@MY‬‬ ‫ﺗﺸﺒﻪ ﺍﻟﻨﺘﺮﺩﺓ ﻋﻤﻠﻴﺔ ﺍﻟﻜﺮﺑﻨﺔ ﻭﺫﻟﻚ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﻟﻨﻴﺘﺮﻭﺟﲔ ﺑﺪ ﹰﻻ ﻣﻦ ﺍﻟﻜﺮﺑﻮﻥ ﺑﺎﻹﺿﺎﻓﺔ ﺇﱃ ﺃﻥ ﻋﻤﻠﻴـﺔ‬ ‫ﺍﻟﻨﺘﺮﺩﺓ ﲢﺘﺎﺝ ﺇﱃ ﺍﻧﻮﺍﻉ ﺧﺎﺻﺔ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﻟﺴﺒﺎﺋﻜﻲ ‪.‬‬ ‫ﻭﺗﺘﻢ ﰲ ﺩﺭﺟﺎﺕ ﺣﺮﺍﺭﺓ ﻣﻨﺨﻔﻀﺔ ﻧﺴﺒﻴﹰﺎ ) ‪ ( oc 500‬ﰲ ﻏﺮﻓﺔ ﳏﻜﻤﺔ ﳝﺮ ﺑﺪﺍﺧﻠـﻬﺎ ﻏﺎﺯﺍﻷﻣﻮﻧﻴـﺎ )‬ ‫ﺍﻟﻨﺸﺎﺩﺭ (‬ ‫‪@ @ñ†äîÛbi@†îÜ–nÛa@@SM@UM@T@MY‬‬ ‫ﻭﰲ ﻫﺬﻩ ﺍﻟﻄﺮﻳﻘﺔ ﻳﻐﻤﺲ ﺍﻟﻔﻮﻻﺫ ﰲ ﻣﺼﻬﻮﺭ ﺳﻴﺎﻧﻴﺪ ﺍﻟﺒﻮﺗﺎﺳﻴﻮﻡ ﻟﻔﺘﺮﺓ ﻗﺼﲑﺓ ﻭﻳﱪﺩ ﺑﻌﺪ ﺫﻟﻚ ﺗﱪﻳـﺪﹰﺍ‬ ‫ﻓﺠﺎﺋﻴﹰﺎ ﺳﺮﻳﻌﹰﺎ ﺣﻴﺚ ﳝﺘﺺ ﺍﻟﻔﻮﻻﺫ ﺑﻌﻀﹰﺎ ﻣﻦ ﺍﻟﻜﺮﺑﻮﻥ ﻭﺍﻟﻨﻴﺘﺮﻭﺟﲔ ﳑﺎ ﻳـﺆﺩﻱ ﺇﱃ ﺯﻳـﺎﺩﺓ ﺍﻟـﺼﻼﺩﺓ‬ ‫ﺍﻟﺴﻄﺤﻴﺔ ﻭﺗﻄﺒﻖ ﻫﺬﻩ ﺍﻟﻄﺮﻳﻘﺔ ﻟﻠﺤﺼﻮﻝ ﻋﻠﻰ ﺗﺼﻠﻴﺪ ﺳﻄﺤﻲ ﻗﻠﻴﻞ ﺍﻟﻌﻤﻖ ‪.‬‬ ‫‪@ @kèÜÛbi@†îÜ–nÛa@@TM@UM@T@MY‬‬ ‫ﺗﺘﻢ ﻋﻤﻠﻴﺔ ﺍﻟﺘﺼﻠﻴﺪ ﺑﺎﻟﻠﻬﺐ ﻋﻠﻰ ﺍﳌﺸﻐﻮﻻﺕ ﺍﻟﻜﺒﲑﺓ ﻭﺫﻟﻚ ﻟﺘﺼﻠﻴﺪ ﻣﻨﺎﻃﻖ ﳏـﺪﺩﺓ ﻣﺜـﻞ ﻣﻮﺍﺿـﻊ‬ ‫ﺍﳌﺮﺗﻜﺰﺍﺕ ﻋﻠﻰ ﺍﶈﺎﻭﺭ ﻭﻳﺘﻢ ﺗﺴﺨﲔ ﺍﻟﺴﻄﺢ ﺑﻠﻬﺐ ﻏﺎﺯ ﻣﺜﻞ ﺧﻠﻴﻂ ﻏﺎﺯ ﺍﻷﺳـﻴﺘﻴﻠﲔ ﻭﺍﻷﻭﻛـﺴﺠﲔ‬ ‫ﻭﻳﺒﻠﻎ ﻋﻤﻖ ﻃﺒﻘﺔ ﺍﻟﺘﺼﻠﻴﺪ ﺃﻗﻞ ﻣﻦ ‪١‬ﻣﻢ ﻭﳝﻜﻦ ﺍﻟﺘﺤﻜﻢ ﻓﻴﻪ ﺑﻮﺍﺳﻄﺔ ﺩﺭﺟﺔ ﺣـﺮﺍﺭﺓ ﺍﻟﻠـﻬﺐ ﻭﻓﺘـﺮﺓ‬ ‫ﺍﻟﺘﺴﺨﲔ ‪.‬‬ ‫‪@ @ïöbiŠèØÛa@s§bi@†îÜ–nÛa@UM@UM@T@MY‬‬ ‫ﻳﺴﺘﺨﺪﻡ ﻣﻠﻒ ﻻﻧﺘﺎﺝ ﳎﺎﻝ ﻣﻐﻨﺎﻃﻴﺴﻲ ﻣﺘﺮﺩﺩ ﳛﺪﺙ ﺗﻴﺎﺭﺍﺕ ﺩﻭﺍﻣﻴﺔ ﰲ ﻗﻄﻌﺔ ﺍﻟﻌﻤﻞ ﻭﻳﺆﺩﻱ ﺳـﺮﻳﺎﻥ‬ ‫ﺍﻟﺘﻴﺎﺭ ﺇﱃ ﺍﺭﺗﻔﺎﻉ ﺳﺮﻳﻊ ﰲ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﻟﻄﺒﻘﺔ ﺍﻟﺴﻄﺤﻴﺔ ﺍﳌﻄﻠﻮﺏ ﺗﺼﻠﻴﺪﻫﺎ ﺣﻴﺚ ﻳﺒﻠﻎ ﻋﻤﻖ ﺍﻟﺘﺼﻠﻴﺪ‬ ‫‪١٨٣‬‬


‫ﻣﻦ ‪ ٠,٢‬ﻣﻢ – ‪ ٥٠‬ﻣﻢ ﻭﺗﺴﺘﺨﺪﻡ ﻫﺬﻩ ﺍﻟﻌﻤﻠﻴﺔ ﰲ ﺃﻏﻠﺐ ﺍﻷﺣﻮﺍﻝ ﰲ ﺍﳌﺸﻐﻮﻻﺕ ﺍﻟﺴﺎﺑﻖ ﺗـﺼﻠﻴﺪﻫﺎ‬ ‫ﻭﺗﻄﺒﻴﻌﻬﺎ ﻭﻣﻦ ﳑﻴﺰﺍﺕ ﻫﺬﻩ ﺍﻟﻄﺮﻳﻘﺔ ﺇﻣﻜﺎﻧﻴﺔ ﺍﻟﺘﺤﻜﻢ ﰲ ﻋﻤﻖ ﺍﻟﻄﺒﻘﺔ ﺍﻟﺴﻄﺤﻴﺔ ﺍﳌﺼﻠﺪﺓ ﻭﻗﻠﺔ ﺍﻟﺘـﺸﻮﻩ‬ ‫ﰲ ﺍﳌﺸﻐﻮﻻﺕ ﺍﻟﻨﺎﺟﻢ ﻣﻦ ﻋﻤﻠﻴﺔ ﺍﻟﺘﺼﻠﻴﺪ ‪.‬‬ ‫‪Annealing ( 3 ) 012 5 – 9‬‬

‫ﻫﻮ ﺍﺣﺪ ﺃﺷﻜﺎﻝ ﺍﳌﻌﺎﳉﺎﺕ ﺍﳊﺮﺍﺭﻳﺔ ﺣﻴﺚ ﻳﺘﻢ ﺗﺴﺨﲔ ﺍﳌﻌﺪﻥ ﺗﺴﺨﻴﻨﹰﺎ ﺑﻄﻴﺌﹰﺎ ﻭﺇﺑﻘﺎﺅﻩ ﻋﻨﺪ ﻫﺬﻩ ﺍﻟﺪﺭﺟﺔ‬ ‫ﻓﺘﺮﺓ ﺯﻣﻨﻴﺔ ﻣﻌﻴﻨﺔ ﻭﻣﻦ ﰒ ﺗﱪﻳﺪﻩ ﺗﱪﻳﺪﹰﺍ ﺑﻄﻴﺌﹰﺎ ﻭﻳﺘﻢ ﺫﻟﻚ ﻋﻠﻰ ﺛﻼﺙ ﻣﺮﺍﺣﻞ ‪:‬‬ ‫• ﺍﻟﺘﺨﻠﺺ ﻣﻦ ﺍﻻﺟﻬﺎﺩﺍﺕ ﺍﻟﺪﺍﺧﻠﻴﺔ‬ ‫• ﺇﻋﺎﺩﺓ ﺍﻟﺘﺒﻠﻮﺭ‬ ‫• ﳕﻮ ﺍﳊﺒﻴﺒﺎﺕ‬ ‫‪@ @à‚nÛa@Êaìãc@Q@M@U@MY‬‬ ‫• ﺍﻟﺘﺨﻤﲑ ﻹﺯﺍﻟﺔ ﺍﻻﺟﻬﺎﺩﺍﺕ ‪:‬‬ ‫ﺣﻴﺚ ﳚﺮﻱ ﺑﻌﺪ ﻋﻤﻠﻴﺎﺕ ﺍﻟﺘﺸﻜﻴﻞ ﺍﻟﻌﻨﻴﻔﺔ ﻣﺜﻞ ﻋﻤﻠﻴﺎﺕ ﺍﻟﺪﺭﻓﻨﺔ ﺃﻭ ﺳـﺤﺐ ﺍﻷﺳـﻼﻙ ﺃﻭ ﺗـﺸﻜﻴﻞ‬ ‫ﺍﻟﺼﻔﺎﺋﺢ ﺍﳌﻌﺪﻧﻴﺔ ‪ ،‬ﺣﻴﺚ ﻳﺘﻐﲑ ﺍﻟﺸﻜﻞ ﺍﻟﺒﻠﻮﺭﻱ ﻟﻠﻤﻌﺪﻥ ﺗﺘﺪﺍﺧﻞ ﺍﻟﺒﻠﻮﺭﺍﺕ ﻣﺴﺘﻮﻳﺎﺕ ﺍﻻﻧـﺰﻻﻕ ﳑـﺎ‬ ‫ﻳﺆﺩﻱ ﺇﱃ ﺇﺟﻬﺎﺩﺍﺕ ﺩﺍﺧﻠﻴﺔ ﻋﻨﻴﻔﺔ ‪ ،‬ﻟﺬﻟﻚ ﻳﻠﺰﻡ ﻫﺬﺍ ﺍﻟﻨﻮﻉ ﻣﻦ ﺃﻧﻮﺍﻉ ﺍﳌﻌﺎﳉـﺎﺕ ﺍﳊﺮﺍﺭﻳـﺔ ﻭﻳـﺘﻢ‬ ‫ﺑﺘﺴﺨﲔ ﺍﳌﻌﺪﻥ ﺇﱃ ‪ 400oc‬ﻭﻣﻦ ﰒ ﻳﺘﺮﻙ ﻳﱪﺩ ﺑﺒﻂﺀ ﺑﺎﻟﻔﺮﻥ ‪.‬‬ ‫• ﺗﱪﻳﺪ ﺇﻋﺎﺩﺓ ﺍﻟﺘﺒﻠﻮﺭ ‪:‬‬ ‫ﻭﻳﺘﻢ ﻹﺯﺍﻟﺔ ﺍﻹﺟﻬﺎﺩﺍﺕ ﺍﻟﺪﺍﺧﻠﻴﺔ ﺍﻟﻨﺎﺷﺌﺔ ﻣﻦ ﺍﻟﺘﺸﻜﻴﻞ ﻋﻠﻰ ﺍﻟﺒﺎﺭﺩ ﻭﻳﺘﻢ ﺑﺘﺴﺨﲔ ﺍﳌﻌﺪﻥ ﺇﱃ ‪700oc‬‬ ‫ﻭﻣﻦ ﰒ ﻳﺘﺮﻙ ﻳﱪﺩ ﺑﺒﻂﺀ ﺩﺍﺧﻞ ﺍﻟﻔﺮﻥ ‪.‬‬ ‫• ﺍﻟﺘﺨﻤﲑ ﺍﳊﺒﻴﱯ ‪:‬‬ ‫ﻭﻳﺘﻢ ﻟﺘﻜﻮﻳﺮ ﺻﻔﺎﺋﺢ ﺍﻟﺴﻤﻨﺘﻴﺖ ﺍﳌﻮﺟﻮﺩﺓ ﰲ ﺍﻟﱪﻟﻴﺖ ﻭﺫﻟﻚ ﺑﺎﻟﺘﺴﺨﲔ ﻭﺍﻟﺘﱪﻳﺪ‪.‬‬

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‫‪Normalizing ( 567 ) 6-9‬‬

‫ﺗﺘﻢ ﻋﻤﻠﻴﺔ ﺍﳌﻌﺎﺩﻟﺔ ﺑﺮﻓﻊ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﻟﺼﻠﺐ ﺍﻋﻠﻰ ﻣﻦ ﺍﻟﺪﺭﺟﺔ ﺍﳊﺮﺟﺔ ﲝﻮﺍﱃ ‪ ٣٠‬ﺩﺭﺟﺔ ﻣﺌﻮﻳـﺔ ﰒ‬ ‫ﻳﺘﻢ ﺍﻟﺘﱪﻳﺪ ﺍﱃ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﻟﻐﺮﻓﺔ ﺑﺎﳍﻮﺍﺀ ﺍﻟﺴﺎﻛﻦ‪.‬‬ ‫‪@ @òÛ…bÈ½a@òîÜàÇ@åß@Ò†a@QMVMY‬‬ ‫• ﲢﺴﲔ ﺍﳋﻮﺍﺹ ﺍﻟﺘﺸﻐﻴﻠﻴﺔ ﻟﻠﺼﻠﺐ‪.‬‬ ‫• ﺗﻮﺣﻴﺪ ﺍﳊﺠﻢ ﺍﳊﺒﻴﱯ ﰲ ﺍﻟﺒﻨﻴﺔ‪.‬‬ ‫• ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﻣﻘﺎﻭﻣﺔ ﻟﻠﺸﺪ ﻭﺻﻼﺩﺓ ﺃﻋﻠﻰ ﻣﻦ ﺍﻟﱵ ﻳﺘﻢ ﺍﳊﺼﻮﻝ ﻋﻠﻴﻬﺎ ﰱ ﺣﺎﻟـﺔ‬ ‫ﺍﻟﺘﺨﻤﲑ ﺍﻟﻜﺎﻣﻞ‪.‬‬ ‫‪Tempering (:;<) 9 7-9‬‬

‫ﺗﺘﻢ ﻋﻤﻠﻴﺔ ﺍﳌﺮﺍﺟﻌﺔ ﻟﺘﻘﻠﻴﻞ ﻗﺼﺎﻓﺔ ﺍﳌﻌﺪﻥ ﻭﺫﻟﻚ ﺑﺮﻓﻊ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺍﻟﺼﻠﺐ ﺍﱃ ﺩﺭﺟﺔ ﺣﺮﺍﺭﺓ ﺃﻗﻞ ﻣﻦ‬ ‫ﺩﺭﺟﺔ ﺍﳊﺮﺍﺭﺓ ﺍﳊﺮﺟﺔ ﺍﻟﺪﻧﻴﺎ ﻭﻣﻦ ﰒ ﺗﺮﻛﻬﺎ ﺗﱪﺩ ﺗﱪﻳﺪﺍ ﺑﻄﻴﺌﺎ‪.‬‬ ‫******‬

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‫ ‬ ‫ ‬ ‫‪ 1-10‬‬

‫ﺻﻼﺩﺓ ﺍﳌﻌﺎﺩﻥ ﻫﻲ ﻗﺪﺭﺓ ﺍﳌﻌﺪﻥ ﻋﻠﻰ ﻣﻘﺎﻭﻣﺔ ﺣﺪﻭﺙ ﻋﻼﻣﺔ ﺑﻪ ﻭﻣﻘﺎﻭﻣﺘﻪ ﻟﻠـﱪﻯ ﻭﺍﻟﺘﺂﻛـﻞ ﻧﺘﻴﺠـﺔ‬ ‫ﺍﻻﺣﺘﻜﺎﻙ ﻧﺘﻴﺠﺔ ﺍﻟﺘﺤﻤﻴﻞ ‪ .‬ﻭﻫﺬﺍ ﺍﻟﺘﻌﺮﻳﻒ ﻳﻌﺘﱪ ﺗﻌﺮﻳﻔﺎ ﻋﺎﻣﺎ ﻭﻫﻨﺎﻙ ﺃﻧﻮﺍﻉ ﳐﺘﻠﻔﺔ ﻟﻠـﺼﻼﺩﺓ ﳝﻜـﻦ‬ ‫ﺗﻌﺮﻳﻔﻬﺎ ﻛﺎﻵﰐ ‪:‬‬ ‫‪@ @Z@òßýÈÛa@ñ…ý•@–@c‬‬

‫ﻫﻲ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﳊﺪﻭﺙ ﻋﻼﻣﺔ ﻧﺘﻴﺠﺔ ﲢﻤﻴﻠﻪ ﲝﻤﻞ ﺍﺳﺘﺎﺗﻴﻜﻰ ﺃﻭ ﺩﻳﻨﺎﻣﻴﻜﻰ ﻭﺍﳌﻌﺎﺩﻥ ﺍﻟﱴ ﳍﺎ ﻣﻘﺎﻭﻣﺔ‬ ‫ﺻﻼﺩﺓ ﻛﺒﲑﺓ ﳝﻜﻦ ﺍﻻﺳﺘﻔﺎﺩﺓ ‪‬ﺎ ﻣﺜﻞ ﻣﺜﻼ ﰲ ﻋﻤﻞ ﺍﻟﺪﺑﺎﺑﺎﺕ ﳌﻨـﻊ ﺍﺧﺘـﺮﺍﻕ ﺍﻟﺮﺻـﺎﺹ ﻭﺍﻟﻘﻨﺎﺑـﻞ‬ ‫ﳉﺪﺭﺍ‪‬ﺎ‪.‬‬ ‫‪@ @Z@…a†m‰üa@ñ…ý•@–@l‬‬

‫ﻫﻲ ﻗﺪﺭﺓ ﺍﳌﻌﺪﻥ ﻋﻠﻰ ﺍﻟﺮﺟﻮﻋﻴﺔ ﺃﻱ ﺍﻣﺘﺼﺎﺹ ﺍﻟﻄﺎﻗﺔ ﻭﺇﻋﺎﺩ‪‬ﺎ ﺛﺎﻧﻴﺔ ﻋﻨـﺪ ﺇﺯﺍﻟـﺔ ﺍﻷﲪـﺎﻝ ﺍﳌـﺆﺛﺮﺓ‬ ‫ﻭﺗﺴﺘﻌﻤﻞ ﺍﳌﻌﺎﺩﻥ ﺍﻟﱴ ﳍﺎ ﺻﻼﺩﺓ ﺇﺭﺗﺪﺍﺩ ﻋﺎﻟﻴﺔ ﰱ ﺻﻨﺎﻋﺔ ﺍﻟﺪﺑﺎﺑﺎﺕ ‪.‬‬ ‫‪@ @Z@”†ä@ñ…ý•@M@;u‬‬

‫ﻫﻰ ﺧﺎﺻﻴﺔ ﻣﻘﺎﻭﻣﺔ ﺳﻄﺢ ﺍﳌﻌﺪﻥ ﻟﻠﺨﺪﺵ ‪ .‬ﻭﺍﳌﻌﺎﺩﻥ ﺍﻟﱴ ﳍﺎ ﺻﻼﺩﺓ ﺧﺪﺵ ﺻﻐﲑﺓ ﻳﻜﻮﻥ ﻣﻦ ﺍﻟﺴﻬﻞ‬ ‫ﺇﺟﺮﺍﺀ ﻋﻤﻠﻴﺎﺕ ﺍﻟﱪﺍﺩﺓ ﳍﺎ ﺃﺛﻨﺎﺀ ﺗﺼﻨﻴﻌﻬﺎ ‪.‬‬ ‫…@–@•‪@ @@H@Wear hardness@I@ÝØ’Ûa@ñ…ý‬‬

‫ﻫﻲ ﻗﺪﺭﺓ ﺍﳌﻌﺪﻥ ﳌﻘﺎﻭﻣﺔ ﺍﻟﱪﻯ ﻭﺍﻟﺘﺂﻛﻞ ﺑﺴﻄﺤﻪ ﻧﺘﻴﺠﺔ ﺍﻻﺣﺘﻜﺎﻙ ﻭﺗﺴﺘﻌﻤﻼ ﺍﳌﻌﺎﺩﻥ ﺍﻟﱴ ‪‬ﺎ ﺻـﻼﺩﺓ‬ ‫ﺗﺄﻛﻞ ﻋﺎﻟﻴﺔ ﰱ ﺗﻐﻠﻴﻒ ﻋﺠﻼﺕ ﺍﻟﻘﻄﺎﺭﺍﺕ ﻭﺳﻄﻮﺡ ﺍﻟﻘﻀﺒﺎﻥ ﻭﰱ ﻋﻤﻞ ﺟـﺰﺍﺀ ﺍﳌﻜﻨـﺎﺕ ﺍﳌﻌﺮﺿـﺔ‬ ‫ﻟﻺﺣﺘﻜﺎﻙ ‪.‬‬ ‫‪@ @Z@pbäØ½bi@ÝîÌ’nÛa@ñ…ý•@M@;ç‬‬

‫ﻭﻫﻰ ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺪﻥ ﻟﻠﺘﺸﻐﻴﻞ ﺑﺎﳌﻜﻨﺎﺕ ﺍﳌﺴﺘﻌﻤﻠﺔ ﰱ ﻋﻤﻠﻴﺎﺕ ﺍﻟﻘﻄﻊ ﻭﺍﻟﺜﻘﺐ ﻭﺍﻟﱪﺩ ‪ ...‬ﺍﱁ ‪ .‬ﺑﺎﻟﻮﺭﺷﺔ‬ ‫ﻭﺍﳌﻌﺎﺩﻥ ﺍﻟﱴ ﳍﺎ ﺻﻼﺩﺓ ﺗﺸﻐﻴﻞ ﻋﺎﻟﻴﺔ ﺗﻘﻠﻞ ﻣﻦ ﺍﻹﻧﺘﺎﺝ ﻭﺗﺘﻄﻠﺐ ﻗﻄﻊ ﻏﻴﺎﺭ ﻛﺜﲑﺓ ﻟﻠﻤﻜﻨﺎﺕ ﺍﳌﺴﺘﻌﻤﻠﺔ‬ ‫ﰱ ﺍﻟﺘﺸﻐﻴﻞ‪.‬‬ ‫‪١٨٧‬‬


‫‪ 2-10‬‬

‫ﺗﻨﺺ ﻣﻌﻈﻢ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻘﺎﺳﻴﺔ ﻋﻠﻰ ﺿﺮﻭﺭﺓ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﺍﻟﺼﻼﺩﺓ ﻟﻠﻤﻌﺎﺩﻥ ﻭﺍﻋﺘﺒﺎﺭﻩ ﻛﺎﺧﺘﺒﺎﺭ‬ ‫ﻗﺒﻮﻝ ﺃﻭ ﺭﻓﺾ ﳍﺎ‪ .‬ﻭﲢﺪﺩ ﺻﻼﺩﺓ ﺍﻟﻌﻼﻣﺔ ﺑﺎﺧﺘﺒﺎﺭ ﺑﺮﻧﻞ ﺃﻭ ﻓﻴﻜﺮﺯﺍ ﻭﳝﻜﻦ ﺍﻻﺳﺘﻔﺎﺩﺓ ﻣـﻦ ﻫـﺬﻩ‬ ‫ﺍﻻﺧﺘﺒﺎﺭﺍﺕ ﰱ ﺻﻨﺎﻋﺔ ﺍﳌﻨﺘﺠﺎﺕ ﺍﳌﻌﺪﻧﻴﺔ ﻛﺎﻵﺗﻰ ‪:‬‬ ‫• ﺿﺒﻂ ﻧﺴﺒﺔ ﺍﻟﻜﺮﺑﻮﻥ ﰱ ﺻﻨﺎﻋﺔ ﺍﻟﺼﻠﺐ ﺣﻴﺚ ﺃﻧﻪ ﻭﺟﺪ ﻛﻠﻤﺎ ﻗﻠﺖ ﻧﺴﺒﺔ ﺍﻟﻜﺮﺑﻮﻥ ﰱ ﺍﳌﻌﺎﺩﻥ‬ ‫ﻛﻠﻤﺎ ﻗﻠﺖ ﺻﻼﺩﺗﻪ ‪.‬‬ ‫• ﻳﺴﺎﻋﺪ ﺗﻌﻴﲔ ﺻﻼﺩﺓ ﺍﳌﻌﺎﺩﻥ ﰱ ﲢﺪﻳﺪ ﻧﻮﻉ ﺍﻻﺳﺘﻌﻤﺎﻝ ﺍﳌﻨﺎﺳﺐ ﻟﻜﻞ ﻣﻌﺪﻥ ﰱ ﺍﻟﺼﻨﺎﻋﺔ‬ ‫• ﺍﻟﺘﺄﻛﺪ ﻣﻦ ﺻﺤﺔ ﻭﺩﻗﺔ ﻋﻤﻠﻴﺎﺕ ﺍﳌﻌﺎﻣﻠﺔ ﺍﳊﺮﺍﺭﻳﺔ ﰱ ﺻﻨﺎﻋﺔ ﺍﳌﻌﺎﺩﻥ ﺣﻴﺚ ﺃﻧﻪ ﻭﺟﺪ ﺃﻥ ﻫـﺬﻩ‬ ‫ﺍﻟﻌﻤﻠﻴﺎﺕ ﺗﺆﺛﺮ ﺗﺄﺛﲑﺍ ﻣﺒﺎﺷﺮﺍ ﻋﻠﻰ ﺻﻼﺩﺓ ﺳﻄﺢ ﺍﳌﻌﺪﻥ ‪.‬‬ ‫•‬

‫ﺍﻟﺘﺤﻜﻢ ﰱ ﻣﺴﺘﻮﻯ ﺍﻹﻧﺘﺎﺝ ﺃﺛﻨﺎﺀ ﺍﻟﺘﺼﻨﻴﻊ ﻭﺫﻟﻚ ﺑﻘﻴﺎﺱ ﺻﻼﺩﺓ ﺍﳌﻨﺘﺠﺎﺕ ﺍﳌﻌﺪﻧﻴـﺔ ﻭﺇﺟـﺮﺍﺀ‬ ‫ﺍﻟﺘﻌﺪﻳﻼﺕ ﺍﳌﻨﺎﺳﺒﺔ ﰱ ﺻﻨﺎﻋﺔ ﺍﳌﻌﺎﺩﻥ ﺇﺫﺍ ﻟﺰﻡ ﺍﻷﻣﺮ ﻟﻠﺤﺼﻮﻝ ﻋﻠـﻰ ﺍﳌﻮﺍﺻـﻔﺎﺕ ﺍﳌﻄﻠﻮﺑـﺔ‬ ‫ﻟﻠﻤﻌﺪﻥ ﻭﺍﳌﻨﺘﺠﺎﺕ‬

‫ﺍﻟﺼﻨﺎ ‪.‬‬

‫• ﳝﻜﻦ ﺑﺈﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭﺍﺕ ﺍﻟﺼﻼﺩﺓ ﺑﻄﺮﻳﻘﺔ ﺑﺮﻧﻞ ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﺍﻟﺘﻘﺮﻳﺒﻴﺔ ﻟﻠﻤﻌـﺪﻥ‬ ‫ﺑﺪﻭﻥ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﻣﺘﻠﻒ ﻟﻪ‪.‬‬ ‫‪3 – 10‬‬

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‫‪@ @@(Brinell Hardness Test) :@ÝãŠi@òÔíŠĐi@æ…bÈàÜÛ@òßýÈÛa@ñ…ý•@‰bjna@@Q@M@S@@MQP‬‬ ‫ﺗﺘﻜﻮﻥ ﻣﻜﻨﺔ ﺍﺧﺘﺒﺎﺭ ﺑﺮﻧﻞ ﻣﻦ ﺍﺳﻄﻮﺍﻧﺔ ﻣﺜﺒﺖ ﰱ ﺍﻋﻼﻫﺎ ﺇﻃﺎﺭ ﻳﺘﺪﱃ ﻣﻨﻪ ﺟﺰﺀ ﳐﺮﻭﻃﻰ ﻣﺜﺒﺖ ﺑﻄﺮﻓﻪ‬ ‫ﻟﺴﻔﻠﻰ ﻛﺮﺓ ﻣﻦ ﺍﻟﺼﻠﺐ ﺍﻟﺼﻠﺪ ﺗﺴﻤﻰ ﻛﺮﺓ ﺑﺮﻧﻞ ﻭﳚﺐ ﺃﻥ ﺗﻜﻮﻥ ﺫﺍﺕ ﺳﻄﺢ ﺃﻣﻠﺲ ﻭﳚﺐ ﺑﻌﺪ‬ ‫ﺇﺟﺮﺍﺀ ﺍﻻﺧﺘﺒﺎﺭ ﺍﻟﺘﺄﻛﺪ ﻣﻦ ﻋﺪﻡ ﺇﻧﺒﻌﺎﺟﻬﺎ ﺃﻭ ﺣﺪﻭﺙ ﺗﻐﲑ ﰱ ﻗﻄﺮﻫﺎ ﻭﺇﻻ ﺃﺻﺒﺤﺖ ﻏـﲑ ﺻـﺎﳊﺔ‬ ‫ﻟﻼﺳﺘﻌﻤﺎﻝ ﻭﻳﻠﺰﻡ ﺍﺳﺘﺒﺪﺍﳍﺎ ﺑﺄﺧﺮﻯ ﺃﻛﱪ ﻣﻨﻬﺎ ‪ .‬ﻭﻛﺮﺓ ﺑﺮﻧﻞ ﻗﺪ ﻳﻜﻮﻥ ﻗﻄﺮﻫﺎ ‪١ ، ٢ ، ٥ ، ١٠‬‬ ‫‪ ،‬ﻣﻠﻠﻴﻤﺘﺮ ‪ .‬ﻭﻳﻮﺟﺪ ﺑﺪﺍﺧﻞ ﺍﻻﺳﻄﻮﺍﻧﺔ ﻣﻜﺒﺲ ﻳﺘﺤﺮﻙ ﺇﱃ ﺃﻋﻠﻰ ﻋﻨﺪ ﺩﻭﺭﺍﻥ ﺍﻟﺬﺭﺍﻉ ﻧﺘﻴﺠﺔ ﻟﻀﻐﻂ‬ ‫ﺍﻟﺰﻳﺖ ﺍﳌﻮﺟﻮﺩ ﺑﺎﻻﺳﻄﻮﺍﻧﺔ ﻋﻠﻴﻪ‪ .‬ﻭﺗﻮﺿﻊ ﺍﻟﻌﻴﻨﺔ ﻋﻨﺪ ﺍﻻﺧﺘﺒﺎﺭ ﻓﻮﻕ ﺍﳌﻜﺒﺲ ﺷﻜﻞ )‪(١-١٠‬‬

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‫‘‪@ @ñ…ý–ÜÛ@ÝãŠi@òäî×bß@HQMQPI@ÝØ‬‬

‫ا ‪P‬‬

‫ آ ة ‪D‬‬

‫‪h‬‬ ‫ ا ‪d‬‬

‫‘‪@ @ÝãŠi@òÔíŠĐi@ñ…ý–Ûa@‰bjna@H@R@MQPI@ÝØ‬‬

‫ﻭﻟﻘﻴﺎﺱ ﺍﳊﻤﻞ ﺍﳌﻮﺟﻮﺩ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﻋﻨﺪ ﺍﻻﺧﺘﺒﺎﺭ ﺗﻮﺻﻞ ﺃﻧﺒﻮﺑﺔ ﺑﺄﺳﻔﻞ ﻭﻳﺮﻛﺐ ﻋﻠﻴﻬـﺎ ﻣﻘﻴـﺎﺱ‬ ‫ﺩﺍﺋﺮﻱ ﻣﺪﺭﺝ ﻳﺘﺤﺮﻙ ﺑﺪﺍﺧﻠﻪ ﻣﺆﺷﺮ ﻧﺘﻴﺠﺔ ﺿﻐﻂ ﺍﻟﺰﻳﺖ ﻣﺒﻴﻨﺎ ﺍﳊﻤﻞ ﺍﳌﻮﺟﻮﺩ ﻋﻠﻰ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ‪.‬‬ ‫‪١٨٩‬‬


‫‪@ @Z@‰bjnüa@paìĐ@Q@MQ@MMS@@MQP‬‬ ‫‪ – ١‬ﳜﺘﺎﺭ ﻗﻄﺮ ﺍﻟﻜﺮﺓ ﺍﳌﻨﺎﺳﺐ ‪ D‬ﻟﻨﻮﻉ ﺍﳌﻌﺪﻥ ﻭﺻﻼﺩﺗﻪ ﻭﺗﺮﻛﺐ ﺍﻟﻜﺮﺓ ﲟﻜﻨﺔ ﺑﺮﻧﻞ ﰒ ﺗﻮﺿﻊ ﻋﻴﻨﺔ‬ ‫ﺍﻻﺧﺘﺒﺎﺭ ﻓﻮﻕ ﺍﳌﻜﺒﺲ ﻭﺃﺳﻔﻞ ﻛﺮﺓ ﺑﺮﻧﻞ ﰒ ﻳﺪﺍﺭ ﺍﻟﺬﺭﺍﻉ ﺣﱴ ﺗﺮﺗﻔﻊ ﺍﳌﻜﺒﺲ ﻭﺗﻼﻣﺲ ﻛﺮﺓ ﺑﺮﻧـﻞ‬ ‫ﺍﻟﻌﻴﻨﺔ‬ ‫‪ -٢‬ﳛﺪﺩ ﺑﺮﻧﻞ ﲪﻞ ﺍﻻﺧﺘﺒﺎﺭ ‪ P‬ﲝﻴﺚ ﻳﻜﻮﻥ ﻣﻨﺎﺳﺒﺎ ﻟﻘﻄﺮ ﻛﺮﺓ ﺑﺮﻧﻞ ﻭﲝﻴﺚ ﳝﻜﻦ ﺍﳊﺼﻮﻝ ﻋﻠﻰ‬ ‫ﺃﺛﺮ ﻣﻨﺎﺳﺐ ﻟﻠﻜﺮﺓ ﺑﺎﻟﻌﻴﻨﺔ ﳝﻜﻦ ﻗﻴﺎﺳﻪ ﺑﺪﻗﺔ ﻭﻳﺮﺍﻋﻰ ﺃﻥ ﻳﻜﻮﻥ ‪:‬‬ ‫أ‪-‬‬

‫‪d‬‬ ‫‪D‬‬

‫= ‪ ٠٥‬ـــــــــــــــــــــــ ‪ = ٠٢٥‬‬

‫ب – إ'&د ا‪ !"#$‬ار = ‬ ‫‪P‬‬ ‫أى أن ‪p‬‬ ‫= أو‬ ‫‪2‬‬ ‫‪D‬‬ ‫‪d2‬‬

‫= ‬

‫ﺣﻴﺚ ‪ d‬ﻗﻄﺮ ﺍﻷﺛﺮ ﺍﻟﺬﻯ ﺳﻴﺤﺪﺙ ﺑﻌﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ‬ ‫ﻭﺑﺎﺳﺘﻌﻤﺎﻝ ﺟﺪﻭﻝ )‪ ( ١- ١٠‬ﳝﻜﻦ ﺇﳚﺎﺩ ﻗﻴﻤﺔ ﺍﳊﻤﻞ ﺍﳌﺴﺘﻌﻤﻞ ﰱ ﺍﻻﺧﺘﺒﺎﺭ ﻭﺫﻟﻚ ﲟﻌﻠﻮﻣﻴـﺔ‬ ‫ﻗﻄﺮ ﺍﻟﻜﺮﺓ ﺍﳌﺴﺘﻌﻤﻠﺔ ﻭﻧﻮﻉ ﺍﳌﻌﺪﻥ ﺍﳌﺨﺘﱪ ﻭﻗﻴﻤﺔ ﺍﻟﺜﺎﺑﺖ ﳍﺬﺍ ﺍﳌﻌﺪﻥ ﻓﻠﻤﻌﺪﻥ ﺍﻟﺼﻠﺐ ﻭﻛﺮﺓ ﺑﺮﻧﻞ‬ ‫ﺍﻟﱴ ﻗﻄﺮﻫﺎ ‪ ١٠‬ﻣﻠﻠﻴﻤﺘﺮ‬ ‫‪@ @ñ…ý–ÜÛ@ÝãŠi@òÔíŠ@âa†‚na@…ë†y@HQMQPIÞë†u‬‬

‫‪@ @oibrÛa‬‬

‫‪@ @ÝãŠi@áÓ‰‬‬

‫‪@ @æ†È½a@Êìã‬‬

‫‪٣٠‬‬

‫ﺣﺪﻳﺪ‬

‫ﺍﻛﱪ ﻣﻦ ‪١٦٠‬‬

‫‪١٠‬‬

‫ﺳﺒﺎﺋﻚ ﳓﺎﺱ ﺍﻭﺍﻟﻮﻣﻨﻴﻮﻡ‬

‫‪١٦٠ - ٦٠‬‬

‫‪٥‬‬

‫ﳓﺎﺱ ‪ -‬ﺍﻟﻮﻣﻨﻴﻮﻡ‬

‫‪٦٠ – ٢٠‬‬

‫‪١‬‬

‫ﺭﺻﺎﺹ ﻭﻗﺼﺪﻳﺮ ﻭﺳﺒﺎﺋﻜﻬﻤﺎ‬

‫ﺍﻗﻞ ﻣﻦ ‪٢٠‬‬

‫‪ – ٣‬ﻳﺪﺍﺭ ﺍﻟﺬﺭﺍﻉ ﻓﻴﺒﺪﺍ ﲢﻤﻴﻞ ﺍﻟﻌﻴﻨﺔ ﺣﱴ ﻳﺼﻞ ﻣﺆﺷﺮ ﺍﻟﺘﺤﻤﻴﻞ ﺇﱃ ﲪﻞ ﺍﻻﺧﺘﺒﺎﺭ ﺍﳌﻄﻠﻮﺏ ﻭﻳﺘﺮﻙ‬ ‫ﻫﺬﺍ ﺍﳊﻤﻞ ﻣﺆﺛﺮﺍ ﻋﻠﻰ ﻗﻄﻌﻰ ﺍﻻﺧﺘﺒﺎﺭ ﻓﺘﺮﺓ ﰱ ﺣﺪﻭﺩ ﻣﻦ ‪ ١٥‬ﺇﱃ ‪ ٣٠‬ﺛﺎﻧﻴﺔ ﰒ ﻳﺰﺍﻝ ﺍﳊﻤﻞ‬ ‫‪ – ٤‬ﻳﻘﺎﺱ ﻗﻄﺮ ﺍﻷﺛﺮ ‪ d‬ﺑﻮﺍﺳﻄﺔ ﳎﻬﺮ ﲟﻘﻴﺎﺱ ﻣﺪﺭﺝ ﻭﳛﺴﺐ ﺭﻗﻢ ﺑﺮﻧﻞ ﻛﺎﻵﺗﻰ ‪:‬‬ ‫ر‪./ $ 012 34‬دة =‬

‫‪ 078‬ار ‪356$‬‬ ‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬ ‫=<‪ 8‬ا‪ 2‬آ‪2‬ة ‪ 012‬ا‪ :$‬ا‪297$‬ة‬

‫‪١٩٠‬‬


‫∴ ر‪./ $ 012 34‬دة =‬

‫‪p‬‬ ‫‪= B.H .N‬‬ ‫‪π Dh‬‬

‫‪ ?7 = h >8‬أ‪ 2‬آ‪2‬ة ‪012‬‬

‫‪p‬‬ ‫ر‪./ $ 012 34‬دة =‬

‫‪d‬‬ ‫‪2‬‬

‫) ‪π D ( D / 2 − ( D / 2) 2 − ( ) 2‬‬ ‫‪p‬‬ ‫) ‪( D − ( D)2 − (d ) 2‬‬

‫‪πD‬‬ ‫‪2‬‬

‫‪8‬وى ‪ 2@4‬آ‪2‬ة ‪37$ 012‬‬ ‫‪ 2@4 = d‬ا‪37$ 2B‬‬ ‫‪ 078 = p‬ار ‪356$‬‬

‫‪@ @@Z@ÝãŠi@‰bjna@õaŠua@†äÇ@òiìÜĐ½a@pbbînyüa@R@@MQ@M@MMS@@MQP‬‬ ‫‪ (١‬ﳚﺐ ﻋﻨﺪ ﲢﻀﲑ ﻗﻄﻌﺔ ﺍﻻﺧﺘﻴﺎﺭ ﺃﻻ ﻳﻘﻞ ﲰﻚ ﻗﻄﻌﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻦ ‪ ١٠‬ﺃﻣﺜﺎﻝ ﻋﻤﻖ ﺍﻷﺛﺮ ‪h‬‬ ‫ﺣﱴ ﻻ ﻳﻈﻬﺮ ﺃﻯ ﺍﻧﺒﻌﺎﺝ ﻟﻠﺴﻄﺢ ﺍﳋﻠﻔﻰ ﻟﻘﻄﻌﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻧﺘﻴﺠﺔ ﺿﻐﻂ ﺍﳊﻞ ﻋﻠﻴﻬﺎ‬ ‫‪ (٢‬ﳚﺐ ﺃﻥ ﻳﻜﻮﻥ ﺳﻄﺢ ﻗﻄﻌﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻣﺼﻘﻮﻻ ﻭﺧﺎﻟﻴﺎ ﻛﻤﻦ ﺍﻟﺰﻳﺖ ﻭﺍﻟﺸﺤﻢ ﺣﱴ ﻻ ﺗﺘﺄﺛﺮ‬ ‫ﻧﺘﻴﺠﺔ ﺍﻻﺧﺘﺒﺎﺭ‪.‬‬ ‫‪ (٣‬ﳚﺐ ﺃﻻ ﺗﻘﻞ ﺍﳌﺴﺎﻓﺔ ﺑﲔ ﻣﺮﻛﺰ ﺑﺮﻧﻞ ﻭﺣﺎﻓﺔ ﻗﻄﻌﺔ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻦ ‪ ٢,٥‬ﻗﻄﺮ ﺍﻷﺛﺮ ﻭﺃﻻ ﺗﻘﻞ‬ ‫ﺍﳌﺴﺎﻓﺔ ﺑﲔ ﻣﺮﻛﺰﻯ ﺃﺛﺮﻳﻦ ﻣﺘﺠﺎﻭﺭﻳﻦ ﻋﻦ ‪ ٤,٠‬ﻗﻄﺮ ﺍﻷﺛﺮ‪.‬‬ ‫‪ (٤‬ﺗﻌﺘﱪ ﻧﺘﺎﺋﺞ ﺍﺧﺘﺒﺎﺭ ﺑﺮﻧﻞ ﻏﲑ ﺻﺤﻴﺤﺔ ﰱ ﺍﻷﺣﻮﺍﻝ ﺍﻵﺗﻴﺔ ‪:‬‬ ‫ﺃ‪ -‬ﺇﺫﺍ ﻛﺎﻥ ﺍﳌﻌﺪﻥ ﺷﺪﻳﺪ ﺍﻟﺼﻼﺑﺔ ﲝﻴﺚ ﻳﻐﲑ ﻣﻦ ﺷﻜﻞ ﻛﺮﺓ ﺑﺮﻧﻞ ﻭﻻ ﳛﺪﺙ ﺍﻟﻌﻼﻣﺔ‬ ‫ﺍﳌﻄﻠﻮﺑﺔ‬ ‫ﺏ‪ -‬ﺇﺫﺍ ﺣﺪﺙ ﺍﻧﺒﻌﺎﺝ ﻟﺴﻄﺢ ﺍﳌﻌﺪﻥ ﻭﻇﻬﺮ ﺃﺛﺮﻩ ﻋﻠﻰ ﺍﳉﺎﻧﺐ ﺍﻵﺧﺮ ﻟﻌﻴﻨﺔ ﺍﻻﺧﺘﺒﺎﺭ ‪.‬‬ ‫ﺕ‪ -‬ﺇﺫﺍ ﻛﺎﻧﺖ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻣﺼﻠﺪﺓ ﺑﺎﻟﺘﻐﻠﻴﻒ ﻭﻛﺎﻥ ﻋﻤﻖ ﺍﻷﺛﺮ ﺍﳊﺎﺩﺙ ﺃﻛﱪ ﻣﻦ ﲰﻚ‬ ‫ﺍﻟﻄﺒﻘﺔ ﺍﳌﺼﻠﺪﺓ ﺣﻴﺚ ﺍﻧﻪ ﰱ ﻫﺬﻩ ﺍﳊﺎﻟﺔ ﻻ ﳝﺜﻞ ﺭﻗﻢ ﺑﺮﻧﻞ ﻟﻠﺼﻼﺩﺓ ﺻﻼﺩﺓ ﺍﳉﺰﺀ‬ ‫ﺍﳌﺼﻠﺪ ‪.‬‬

‫‪١٩١‬‬


‫‪@ @@æ…bÈàÜÛ@†’Ûa@òßëbÔß@íë@ñ…ý–ÜÛ@ÝãŠi@áÓ‰@í@òÓýÈÛa@S@MQ@MMS@@MQP‬‬ ‫ﻭﺟﺪ ﺑﺮﻧﻞ ﻋﻤﻠﻴﺎ ﺃﻥ ﻫﻨﺎﻙ ﻋﻼﻗﺔ ﺗﻘﺮﻳﺒﻴﺔ ﺑﲔ ﺭﻗﻢ ﺑﺮﻧﻞ ﻟﻠﺼﻼﺩﺓ ﻭﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﳑﺎ ﻳﻔﻴﺪ ﰱ ﻣﻌﺮﻓﺔ‬ ‫ﻣﻘﺎﻭﻣﺔ ﺍﳌﻌﺎﺩﻥ ﻟﻠﺸﺪ ﺑﺪﻭﻥ ﺇﺟﺮﺍﺀ ﺍﺧﺘﺒﺎﺭ ﻣﺘﻠﻒ ﻋﻠﻴﻬﺎ ‪.‬‬ ‫ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﺑﺎﻟﻜﺠﻢ ‪ /‬ﻣﻢ‪ = ٢‬ﺭﻗﻢ ﺑﺮﻧﻞ × ‪٠,٣٦‬‬ ‫ﻣﺜﺎﻝ‬ ‫ﺍﺟﺮﻯ ﺍﺧﺘﺒﺎﺭ ﺑﺮﻧﻞ ﻟﻠﺼﻼﺩﺓ ﻋﻠﻰ ﻋﻴﻨﺔ ﻣﻦ ﺍﻟﺼﻠﺐ ﺑﺈﺳﺘﺨﺪﺍﻡ ﻛﺮﺓ ﺑﺮﻧﻞ ﻗﻄﺮﻫﺎ ‪ ٥‬ﻣﻢ ﻓﺈﺫﺍ ﻛﺎﻥ ﻗﻄﺮ‬ ‫ﺍﻷﺛﺮ ‪ ٢‬ﻣﻢ ‪ .‬ﺍﺣﺴﺐ ﺭﻗﻢ ﺑﺮﻧﻞ ﻟﻠﺼﻼﺩﺓ ﻭﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﺍﻟﺘﻘﺮﻳﺒﻴﺔ ﻟﻠﺼﻠﺐ ﺍﳌﺨﺘﱪ ‪.‬‬ ‫ﺍﳊﻞ‬ ‫ﺣﻴﺚ ﺃﻥ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﻣﻦ ﺍﻟﺼﻠﺐ‬ ‫ﺍﻟﺜﺎﺑﺖ =‬

‫‪P‬‬ ‫‪D2‬‬

‫= ‪30‬‬

‫ﲪﻞ ﺍﻻﺧﺘﺒﺎﺭ = ‪ × ٣٠‬ﻣﺮﺑﻊ ﻗﻄﺮ ﻛﺮﺓ ﺑﺮﻧﻞ ﺍﳌﺴﺘﻌﻤﻠﺔ ‪.‬‬ ‫= ‪ ٧٥٠ = ٢(٥)× ٣٠‬ﻛﺠﻢ‬

‫ﺭﻗﻢ ﺑﺮﻧﻞ ﻟﻠﺼﻼﺩﺓ ) ‪) = ( B.H.N...‬‬ ‫=‬

‫‪P‬‬ ‫‪D2 − d 2‬‬

‫‪(πD / 2 )(D −‬‬

‫)‬

‫‪750‬‬

‫‪2 × 2 − 5 × 5 − 5 × 2.5 × 3.14‬‬

‫(‬

‫= ‪٢٣٥‬‬ ‫ﻣﻘﺎﻭﻣﺔ ﺍﻟﺸﺪ ﺍﻟﺘﻘﺮﻳﺒﻴﺔ = ‪ × ٠,٣٦‬ﺭﻗﻢ ﺑﺮﻧﻞ ﻟﻠﺼﻼﺩﺓ‬ ‫= ‪ ٨٤,٥ = ٢٣٥ × ٠,٣٦‬ﻛﺠﻢ ‪ /‬ﻣﻢ‬

‫‪٢‬‬

‫‪@ @@(Vickers Hardness Rest)@Z@‹ŠØîÏ@òÔíŠĐi@òßýÈÛa@ñ…ý•@‰bjna@@RMS@MQP‬‬ ‫ﳚﺮﻯ ﻫﺬﺍ ﺍﻻﺧﺘﺒﺎﺭ ﺑﻮﺍﺳﻄﺔ ﺟﻬﺎﺯ ﺧﺎﺹ ﻳﺴﻤﻰ ﺟﻬﺎﺯ ﻓﻴﻜﺮﺯ ‪ ،‬ﺗﻘﺮﻳﺒﺎ ﺑﻨﻔﺲ ﻃﺮﻳﻘﺔ ﺑﺮﻧﻞ ﻣﻊ ﺍﺳﺘﺒﺪﺍﻝ‬ ‫ﻛﺮﺓ ﺑﺮﻧﻞ ‪‬ﺮﻡ ﺩﻗﻴﻖ ﻣﻦ ﺍﳌﺎﺱ ﻗﺎﻋﺪﺗﻪ ﻣﺮﺑﻊ ﻭﻳﺘﻘﺎﻃﻊ ﻛﻞ ﺳﻄﺤﲔ ﻣﺘﻘﺎﺑﻠﲔ ﳍﺬﺍ ﺍﳍﺮﻡ ﻋﻠﻰ ﺯﺍﻭﻳـﺔ‬ ‫‪ ١٣٦ -‬ﺩﺭﺟﺔ ‪.‬‬

‫‪١٩٢‬‬

‫‪θ‬‬


‫ا ‪P‬‬ ‫! ا ‬

‫ا " ‬

‫ ار‬

‫‘‪@ @‹ŠØîÏ@òÔíŠĐi@ñ…ý–Ûa@‰bjna@H@S@MQPI@ÝØ‬‬

‫@‪@ @@‰bjnüa@paìĐ@@QMMMRM@S@MQP‬‬ ‫‪ – ١‬ﺗﻮﺿﻊ ﻗﻄﻌﻰ ﺍﻻﺧﺘﺒﺎﺭ ﻋﻠﻰ ﺳﻨﺪﺍﻥ ﻓﻴﻜﺮﺯ ﰒ ﻳﺮﻓﻊ ﻫﺬﺍ ﺍﻟﺴﻨﺪﺍﻥ ﺑﻮﺍﺳﻄﺔ ﻟﻮﻟﺐ ﻣﺜﺒﺖ ﺑﺴﻔﻠﻪ‬ ‫ﺣﱴ ﺗﻼﻣﺲ ﺍﻟﻌﻴﻨﺔ ﺍﳍﺮﻡ ﺍﳌﺎﺳﻰ ﳉﻬﺎﺯ ﻓﻴﻜﺮﺯ ‪.‬‬ ‫‪ – ٢‬ﲢﻤﻞ ﺍﻟﻌﻴﻨﺔ ﺍﳌﺨﺘﱪﺓ ﺑﻮﺍﺳﻄﺔ ﺭﺍﻓﻌﺔ ﻧﺴﺒﺔ ﺃﺫﺭﻋﻬﺎ ‪ ٢٠ : ١‬ﲝﻤﻞ ‪ P‬ﻣﻘﺪﺍﺭﻩ ‪ ١٠٠‬ﺃﻭ ‪ ٥٠‬ﺃﻭ‬ ‫‪ ٣٠‬ﺃﻭ ‪ ٢٠‬ﺃﻭ ‪ ١٠‬ﺃﻭ ‪ ٥‬ﻛﺠﻢ ﺣﺴﺐ ﺻﻼﺩﺓ ﺍﳌﻌﺪﻥ ﺍﳌﺨﺘﱪ ‪.‬‬ ‫‪ – ٣‬ﻳﺮﻓﻊ ﺍﳊﻤﻞ ﻭﳜﻔﺾ ﺍﻟﺴﻨﺪﺍﻥ ﺑﻮﺍﺳﻄﺔ ﺍﻟﻠﻮﻟﺐ ﰒ ﻳﻘﺎﺱ ﺃﻛﱪ ﻣﻘﺎﺱ ﻟﻘﻄﺮ ﺍﻷﺛﺮ ‪ D‬ﺑﻮﺍﺳﻄﺔ‬ ‫ﺍﳌﻴﻜﺮﻭﺳﻜﻮﺏ ﺍﳌﺜﺒﺖ ﲜﻬﺎﺯ ﻓﻴﻜﺮﺯ ‪.‬‬ ‫ﺭﻗﻢ ﻓﻴﻜﺮﺯ ﻟﻠﺼﻼﺩﺓ‬ ‫) ‪2 P sin (θ / 2‬‬ ‫=‬ ‫‪D2‬‬ ‫‪P‬‬ ‫=‬ ‫‪D2‬‬

‫‪1.854‬‬

‫ﺣﻴﺚ ‪ = P‬ﺍﳊﻤﻞ ﺑﺎﻟﻜﺠﻢ‬ ‫‪ = D‬ﻗﻄﺮ ﺍﻻﺛﺮ ﺍﳊﺎﺩﺙ ﺑﺎﳌﻠﻠﻴﻤﺘﺮ ‪.‬‬ ‫‪١٩٣‬‬


‫‪@ @@Z@‹ŠØîÏ@òÔíŠĐi@æ…bÈàÜÛ@òßýÈÛa@ñ…ý•@‰bjna@bíaŒß@RMMRM@S@MQP‬‬ ‫‪ – ١‬ﻳﻌﻄﻰ ﻗﻴﻤﺔ ﺩﻗﻴﻘﺔ ﻟﺮﻗﻢ ﺍﻟﺼﻼﺩﺓ‬ ‫‪ – ٢‬ﺍﻷﲪﺎﻝ ﺍﳌﺆﺛﺮﺓ ﺻﻐﲑﺓ ﺇﺫﺍ ﻣﺎ ﻗﻮﺭﻧﺖ ﺑﺎﻷﲪﺎﻝ ﺍﳌﺆﺛﺮﺓ ﰱ ﺍﺧﺘﺒﺎﺭ ﺑﺮﻧﻞ ‪.‬‬ ‫‪ – ٣‬ﳝﻜﻦ ﺑﻮﺍﺳﻄﺘﻪ ﲢﺪﻳﺪ ﺻﻼﺩﺓ ﺍﳌﻌﺎﺩﻥ ﺷﺪﻳﺪﺓ ﺍﻟﺼﻼﺩﺓ ﻧﻈﺮﺍ ﻻﺳﺘﺨﺪﺍﻡ ﺍﳍﺮﻡ ﺍﳌﺎﺳﻰ‪.‬‬ ‫‪ – ٤‬ﳝﻜﻦ ﺑﻮﺍﺳﻄﺘﻪ ﲢﺪﻳﺪ ﺻﻼﺩﺓ ﺍﳌﻌﺎﺩﻥ ﺍﻟﺮﻗﻴﻘﺔ ﺍﻟﺴﻤﻚ ﻭﺍﻟﱴ ﻻ ﻳﺼﻠﺢ ﳍﺎ ﺍﺧﺘﺒﺎﺭ ﺑﺮﻧﻞ‬ ‫ﻣﺜﺎﻝ‬ ‫ﻋﲔ ﺭﻗﻢ ﻓﻴﻜﺮﺯ ﻟﻠﺼﻼﺩﺓ ﻟﻌﻴﻨﺔ ﻣﻦ ﺍﻟﺼﻠﺐ ﺇﺫﺍ ﻛﺎﻥ ﲪﻞ ﺍﻻﺧﺘﺒﺎﺭ ﺍﳌﺴﺘﺨﺪﻡ ‪ ١٠٠‬ﻛﺠﻢ ﻭﻗﻄﺮ ﺃﺛﺮ‬ ‫ﺍﳍﺮﻡ ﻋﻠﻰ ﺳﻄﺢ ﺍﻟﻌﻴﻨﺔ ﺑﻌﺪ ﺍﻻﺧﺘﺒﺎﺭ ‪ ٠,٩٣‬ﻣﻢ ‪.‬‬ ‫ﺍﳊــــﻞ‬ ‫ﺭﻗﻢ ﻓﻴﻜﺮﺯ ﻟﻠﺼﻼﺩﺓ = ‪× ١,٨٥٤‬‬ ‫= ‪× ١,٨٥٤‬‬

‫ا‪ 07E$‬آ‪35‬‬ ‫ــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬ ‫‪٢‬‬ ‫=<‪ 8‬ا‪ :@4 2‬ار =‪3‬‬ ‫‪١٠٠‬‬ ‫ـــــــــــــــــ‬ ‫‪٢‬‬ ‫‪٠٩٣‬‬

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‫‪١٩٤‬‬

‫= ‪٢١٥‬‬

كتاب خواص المواد واختباراتها الجزء الاول

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