Descripcion y funcionamiento de una celda HullDescripción completa
Strirred Tank Reactor
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Strirred Tank ReactorFull description
contoh surat pengantar pembuatan STRFull description
Deskripsi lengkap
double hullFull description
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Electroquimica
Deskripsi lengkap
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za drzavniFull description
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DNV’s Hull Structure course for World Wide Shipping 8 - Hull ull Stru Struct ctu ure – carg cargo o area area Deck
Hull Structural Breakdown Deck 1.
Side
2.
Bottom
3.
Deck
4.
Transverse bulkhead
5.
Longitudinal bulkhead
6.
Web frames
Slide 2
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3.
Deck
Structural functions of deck
3.
Deck
Flange in hull girder - Deck Deck platin plating g and long longitu itudin dinals als act as as the the upper upper flang flangee in the hull girder beam
Slide 3
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Structural build up of deck – single skin tanker Deck Deck plat platin ing g w/longitudinals Transv Transvers ersee deck deck girder girder / Web Web frame frame
Slide 4
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Deck Deck CL girder girder
3.
Deck
Longitudinal stresses in deck
Longitudinal stresses from bending of hull girder is maximum at midship Midshi Midship p area area most most susceptible to fatigue cracking and buckling
Bending moment
Slide 5
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3.
Deck
Characteristic damages
1. Crack rackss in dec deck lon longit gitudin udinal alss 2. Crack in in de deck pl plating 3. Corrosion of deckhead 4. Buckling of deck
Slide 6
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3.
Deck
Cracking in deck longitudinals longitudinals
3.
Deck
Deck Deck longit longitudi udinal nal connection connection to web frames
Deck Deck longit longitudi udinal nal conn connec ecti tion on to transv transvers ersee bulkhe bulkhead ad
Slide 7
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Cause for cracking in deck longitudinals
3.
The wave induced excitation of the hull girder leads to dynamic axial stress in the deck longitudinals +
+
_
_
The cyclic vari ariati ation of axi axial stress may lead to fatigue cracks initia initiatin ting g at hot spots spots A loaded condition will normally induce compression stress in the deck (sagging) ASlideballast condition 8 16.03.2004 will normally induce tension stress in the deck (hogging)
Deck
Cracks in deck longitudinals longitudinals
- May resu result lt in in oil oil spill spill on deck deck - Corros Corrosion ion is highly influe influencing ncing the fatigue fatigue life life of a detail - A crack crack could could develop develop furt further her in the the deck plating (brittle fracture)
Slide 9
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3.
Deck
Cracking in deck longitudinals longitudinals Oil Tanker 135,000 135,000 DWT DWT built built 1991 Crack main deck plating
Slide 10
Crack in underde underdeck ck support support for hose hose handling handling crane crane (P/S, midshi midship p area)
16.03.2004
3.
Deck
Characteristic damages
1. Crack rackss in dec deck lon longit gitudin udinal alss 2. Crack in in de deck pl plating 3. Corrosion of deckhead 4. Buckling of deck
Slide 11
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3.
Deck
Openings in deck
Longitudinal stress-flow around manhole in deck
Slide 12
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3.
Deck
Increased stress level around openings in deck!
Example: crack in scallop in deck longitudinal
3.
Deck
Oil Tanker 123,000 123,000 DWT built built 2000 Crack main deck plating (after 3 years)
Slide 13 Scallop in deck16.03.2004 longitudinal is close to access opening in deck. deck. This will give an additional
Crack in deck plating
3.
Tanker for Oil 99328 DWT built 1996 Crack in deck plating
Crack in deck plating at hose saddle support support (midshi (midship p area) Slide 14
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Deck
Characteristic damages
1. Crack rackss in dec deck lon longit gitudin udinal alss 2. Crack in in de deck pl plating 3. Corrosion of deckhead 4. Buckling of deck
Slide 15
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3.
Deck
Corrosion of deckhead
The The ulla ullage ge space space (dec (deckh khead ead)) is an an area area susceptible to general corrosion
Slide 16
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3.
Deck
Corrosion of deckhead
3.
Deck
A reduction of the deck transverse sectional area area due to general corrosion will lead to an increased stress level in deck
Higher str Higher stress ess level le vel in deck deck
σ L
Longitudinal stress
Force
σ
L
F =
n.a.
A Area σ L
Longitudinal stress distribution
Long. stress distribution (wit (with h redu reduce ced d deck deck sectio sectional nal area) area)
Reduced sectional area in deck may lead to plate buckling Slide 17
16.03.2004
Corrosion of deckhead
3.
Deck
Higher High er st stre ress ss lev level el in dec deck k due to general corrosion σ L
Longitudinal stress
Force
σ
L
F =
A Area
σ L
A reduction of the deck deck transverse sectional sectional area due to general corrosion will lead Slide 18
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may lead to buckling problems
Corrosion of deckhead
3.
Deck
Flatba Flatbars rs have have poor poor buckling capacity
Slide 19
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L-profiles have good buckling capacity
Characteristic damages
1. Crack rackss in dec deck lon longit gitudin udinal alss 2. Crack in in de deck pl plating 3. Corrosion of deckhead 4. Buckling of deck
Slide 20
16.03.2004
3.
Deck
Buckling in deck Buckling in deck is most likely to occur in the midship region where the hull girder bending moment is at its maximum
Buck Buckli ling ng of a plate plate fiel field d (pla (plati ting ng with with stif stiffe fene ners rs)) Slide 21
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3.
Deck
Cause for buckling in deck
3.
Deck
Buckling in deck is a result of in plane compression forces in excess of the buckling capacity of the deck plate field Such a situation situation may occur if the transverse transverse section of the deck deck is reduced due to general corrosion and the vessel is in a fully loaded (sagging) condition
Buckling of complete plate field Slide 22
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The deck buckling may take the form of one plate plate between between two deck deck longitud longitudinals inals or in worst case a complete plate field (both deck plating with stiffeners)
Corros Corrosion ion of of dec deckhe khead ad / buckli buckling: ng:
3.
Deck
- heavy corrosion corrosion of of deck deck may lead lead to to buckling - small buckles buckles (plate (plate between between stiffeners) is a strong warning sign that longitudinal stresses are high - large buckle buckless (plate (plate field) field) may may lead to to loss of global strength and in worst case a total collapse of the hull girder
Remember max 10% diminution of deck transverse sectional area! Slide 23
