8/8/2017
Coursework NA5005
Yan Naing Shin
Table of Contents PARTICULARS ................................................................................................................................................... 2 3-2-1/3
LONGITUDINAL HULL GIRDER STRENGTH ........................................................................................3
3-2-1/5
HULL GIRDER MOMENT O F INERTIA ................................................................................................3
3-2-2/3.1
SIDE SHELL PLATING AMIDSHIPS .................................................................................................3
3-2-2/3.5.1
BOTTOM SHELL PLATING ........................................................................................................ 4
3-2-3/1.1
DECK PLATING THICKNESS .......................................................................................................... 4
3-2-7/3.1
LONGITUDINAL B ULKHEAD SCANTLINGS ..................................................................................... 4
ACTUAL THICKNESSES OF SHELL, DECK AND B ULKHEAD PLATING .................................................................... 5 5-2-1/7 3-2-4/3.11
REQUIRED SECTION MO DULI OF BEAMS, FRAMES, GIRDER S AND LONGITUDINALS ........................ 6 MINIMUM THICKNESS O F WEB PORTIONS OF GIR DERS AND TR ANSVERSES ............................... 8
ACTUAL SCANTLINGS OF BEAMS, FRAMES, GIRDERS AND L ONGITUDINALS .................................................... 8
DECK LONGITUDINALS (L – 75X75X8) ........................................................................................................................ 8 DECK GIRDERS (T – 250X8.5 + 100X8)...................................................................................................................... 8 DECK TRANSVERSES (250X8 FLG. 100) ...................................................................................................................... 9 SIDE FRAMES (L – 75X75X8) .................................................................................................................................... 9 SIDE WEB FRAMES (250X8 FLG. 100) ....................................................................................................................... 9 BOTTOM LONGITUDINALS (L – 100X100X8) ............................................................................................................... 9 BOTTOM GIRDERS (T – 350X8.5 + 100X8) ............................................................................................................... 10 BOTTOM TRANSVERSES (350X8 FLG. 100) ............................................................................................................... 10 3-2-7/3.5
LONGITUDINAL BULKHEAD STRINGERS ..................................................................................... 11
3-2-7/3.3
LONGITUDINAL B ULKHEAD STIFFENERS .................................................................................... 11
3-2-7/3.5
LONGITUDINAL B ULKHEAD W EBS ............................................................................................. 11
ACTUAL SCANTLINGS OF BUL KHEAD STRINGERS AND STIFFENERS ................................................................ 12
BULKHEAD STRINGERS (T – 250X8 + 100X8) ............................................................................................................ 12 BULKHEAD STIFFENERS (L – 75X75X8) ..................................................................................................................... 12 BULKHEAD WEBS (250X8 FLG. 100) ....................................................................................................................... 12 MOMENT OF INERTIA OF SECTIONS ABOUT THEIR OWN AXES ...................................................................... 13 SECTION MODULUS CALCULATION ................................................................................................................ 14
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Particulars Molded depth, D 85% of D at 85%D, Lwl
= 2.8 m = 2.38 m = 59.905 m
Rule length, L
= 96% of Lwl
Breadth, B
= 13.716 m
Draught, T
= 1.6 m
Cb
= 0.81092493
Cargo hold length
= 9.7536
= 57.5088 m
m
Spacing of transverses = 609.6 mm Spacing of longitudinals = 500 mm
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3-2-1/3
Longitudinal Hull Girder Strength
The required hull girder section modulus SMR amidships, to the deck and bottom is to be obtained from the following equation: SMR = K SM b cm2-m K = 0.629 + Ms/(f p SMb) but is not to be taken less than 1.0 Ms = maximum still-water bending moment Maximum still-water bending moment is neither available nor necessary to be submitted (because L<76m). Therefore, K is taken as 1.0. SMb = C1C2L2B(Cb + 0.7) cm2-m C1 C2 L B Cb SMb SMR
= 16.33(L/100)2 – 15.47(L/100) + 7.77 = 4.27415 = 0.01 = 57.5088 m = 13.716 m = 0.8109 = 2929.419501 cm 2-m = K SM b = 2929.419501 cm 2-m
3-2-1/5
Hull Girder Moment of Inertia
The hull girder moment of inertia I amidships is to be not less than obtained from the following equation: I = 0.03SMRL cm2-m2 SMR L I
= 2929.419501 cm 2-m = 57.5088 m = 5054.022005 cm2-m2
3-2-2/3.1 Side Shell Plating Amidships The thickness of the side shell plating within 0.4L amidships is not to be less than obtained from the following equation:
t L s t
t = 0.07L + 0.007s mm = required thickness of plating = 57.5088 m = frame spacing, in mm = 609.6 mm = 8.292816 mm = 8.5 mm (rounded)
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3-2-2/3.5.1
Bottom Shell Plating
The thickness of the bottom shell plating within 0.4L amidships is not to be less than that obtained from the following equation: t = 0.045L + 0.007s + 1.8 mm t L s
= required thickness of plating = 57.5088 m = frame spacing, in mm = 500 mm
t
= 8.637896 mm = 9 mm (rounded)
3-2-3/1.1 Deck Plating Thickness Thickness of strength decks with longitudinal beams is to be not less than 3-2-3/1.1.2(a) and 3-2-3/1.1.2(b), below.
s L
1.1.2(a)
t = 0.009s + 2.4 mm
1.1.2(b)
t=
(+48.76) 26+8681
mm
= spacing of deck beams, in mm = 500 mm = 57.5088 m
1.1.2(a)
t
1.1.2(b)
t
= 6.9 mm = 7 mm (rounded) = 5.221 mm = 5.5 mm (rounded)
3-2-7/3.1 Longitudinal Bulkhead Scantlings Plating of cargo tank bulkheads is to be of thickness obtained from the following equation: t = [sk √(qh)/254] + 2.5 mm t s k
= thickness, in mm = stiffener spacing, in mm = (3.075 a – 2.077)/(a + 0.272)
a q Y h
= 1.0 where a > 2 = aspect ratio of the panel (longer edge/shorter edge) = 235/Y (24/Y, 34000/Y) = as defined in 3-2-6/5.1 = as defined in 5-2-1/3
s a
= 609.6 mm = 9753.6/2800 = 3.4834 >2
where (1 ≤ a ≤ 2)
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So, k Y q
= 1.0 = 235 MPa = 235/Y = 1
Calculation of ‘h’ according to 5 -2-1/3
h = h1 h1 = ρht+ ha
m
ρ = 1.0 ht = 2.8 m
ha1 = 1.22 m ha2 = 9.95pv According to 5C-1-7/11.11 of Steel Vessel Rules, pv ≤ 0.21 bar. Assume pv = 0.21 bar. ha2 = 9.95pv = 2.0895 m ha2 > ha1 Therefore, ha = ha2 = 2.0895 m h = h1 = ρht+ ha = 1.0 x 2.8 +2.0895 = 4.8895 m Thickness of the longitudinal bulkhead, t
= [sk √(qh)/254] + 2.5 mm = [609.6x1.0 √(1x4.8895)] + 2.5 = 7.79 mm = 8 mm (rounded)
Actual Thicknesses of Shell, Deck and Bulkhead Plating
Plating Side Bottom
Required thickness (mm)
Actual Thickness (mm) 8.5 9
9 9
Keel
9
10
Deck
7
7
Longitudinal bulkhead
8
8
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5-2-1/7 Required Section Moduli of Beams, Frames, Girders and Longitudinals Deck beams and bottom and side shell frames, in association with the plating to which they are attached, are to have a section modulus SM not less than obtained from the following equation: SM = 7.8chsl2 cm3 Deck longitudinals c
= 1.25
h
= 2.0895 m
s
= 0.5 m
l
= 1.8288 m
SM
= 7.8chsl2 = 34.068 cm3 = 34068.21832 mm3
Deck girders c
= 1.25
h
= 2.0895 m
s
=2m
l
= 1.8288 m
SM
= 7.8chsl2 = 136.2728733 cm 3 = 136272.8733 mm3
Deck transverses c
=1
h
= 2.0895 m
s
= 1.8288 m
l
=2m
SM
= 7.8chsl2 = 119.2238611cm3 = 119223.8611 mm3
Side frames c
= 1.25
h
= 2.0916 m
s
= 0.6096 m
l
= 1.4 m
SM
= 7.8chsl2 = 24.36600217 cm 3 = 24366.00217 mm3
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Side web frames c
= 1.25
h
= 2.0916 m
s
= 1.8288 m
l
= 1.4 m
SM
= 7.8chsl2 = 73.09800651cm3 = 7.31E+04 mm 3
Bottom long'ls c
= 1.34
h
= 4.8895 m
s
= 0.5 m
l
= 1.8288 m
SM
= 7.8chsl2 = 85.46066777 cm 3 = 85460.66777 mm3
Bottom girders c
= 1.34
h
= 4.8895 m
s
=2m
l
= 1.8288 m
SM
= 7.8chsl2 = 341.8426711 cm 3 = 341842.6711 mm3
Bottom transverses c h s l
= 1.25 = 4.8895 m = 1.8288 m =2m
SM
= 7.8chsl2 = 348.7347864 cm 3 = 348734.7864 mm3
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3-2-4/3.11 Minimum Thickness of Web Portions of Girders and Transverses Web portions of girders and transverses are to have a thickness of not less than 1 mm per 100 mm of depth plus 3 mm nor is the thickness to be less than: t = L1/20 + 5.33 mm t L1
= minimum thickness of the web, in mm = L = 57.5088 m
t
= 8.20544 mm = 8.5 mm (rounded)
Actual Scantlings of Beams, Frames, Girders and Longitudinals The neutral axis of each item is initially assumed to be and the base of the attached plating.
Deck Longitudinals (L – 75x75x8) Web Web thickness Flange Flange thickness Plate thickness spacing area
75 8
centroid
19.26595745
I0
2.99E+05
75
Ad2
5.67E+06
8 7
IANA ITNA
5.97E+06 4.22E+06
SM (mm3)
5.97E+04
Required SM
3.41E+04
500 4700
Deck Girders (T – 250x8.5 + 100x8) Web Web thickness Flange
250 8.5 100
centroid I0 Ad2
31.80502216 1.11E+07 9.17E+07
Flange thickness
8
IANA
1.03E+08
Plate thickness
7
ITNA
8.57E+07
SM (mm3) Required SM
3.68E+05 1.36E+05
spacing area
2000 16925
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Deck Transverses (250x8 FLG. 100) Web Web thickness Flange Flange thickness Plate thickness spacing area
250 8
centroid
33.17644344
I0
1.05E+07
100 8
Ad2 IANA
8.95E+07 1.00E+08
7
ITNA
8.28E+07
SM (mm3) Required SM
3.57E+05 1.19E+05
1828.8 15601.6
Side Frames (L – 75x75x8) Web Web thickness Flange Flange thickness Plate thickness spacing area
75 8
centroid
16.00253855
I0
3.16E+05
75
Ad2
5.96E+06
8
IANA
6.27E+06
8.5
ITNA
4.64E+06
SM (mm3) Required SM
6.14E+04 2.44E+04
609.6 6381.6
Side Web Frames (250x8 FLG. 100) Web Web thickness
250 8
centroid I0
Flange
100
Ad2
9.11E+07
IANA
1.02E+08
ITNA SM (mm3)
8.55E+07 3.61E+05
Required SM
7.31E+04
Flange thickness Plate thickness spacing area
8 8.5 1828.8 18344.8
29.60323361 1.05E+07
Bottom Longitudinals (L – 100x100x8) Web Web thickness Flange Flange thickness Plate thickness spacing area
100 8
centroid
25.87704918
I0
7.01E+05
100 8
Ad2 IANA
1.31E+07 1.38E+07
9
ITNA
9.71E+06
SM (mm3)
1.07E+05
Required SM
8.55E+04
500 6100
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Bottom Girders (T – 350x8.5 + 100x8) Web
350
centroid
Web thickness
8.5
I0
3.05E+07
Flange Flange thickness
100 8
Ad2 IANA
2.07E+08 2.37E+08
9
ITNA
1.98E+08
SM (mm3) Required SM
6.10E+05 3.42E+05
Plate thickness spacing area
2000 21775
42.19517796
Bottom Transverses (350x8 FLG. 100) Web
350
centroid
Web thickness Flange
8 100
I0 Ad2
43.8535136 2.87E+07 2.01E+08
Flange thickness
8
IANA
2.29E+08
Plate thickness
9
ITNA
1.91E+08
SM (mm3) Required SM
5.90E+05 3.42E+05
spacing area
1828.8 20059.2
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3-2-7/3.5 Longitudinal Bulkhead Stringers Stringers which support bulkhead stiffeners are to have a section modulus SM obtained from the following equation. SM = 4.74chsl2Q cm3 c h s l Q
= 1.5 = 3.4895 m = 1.4 m = 1.8288 m =1
SM
= 4.74chsl2Q = 116.1698063 cm 3 = 1.16E+05 mm3
3-2-7/3.3 Longitudinal Bulkhead Stiffeners Bulkhead stiffeners, in association with the plating to which it is attached, is to have a section modulus SM not less than that obtained from the following equation: SM = 7.8chsl2Q cm3 c h s l
= 1.0 = 4.1895 m = 0.6096 m = 1.4 m
Q
= 1.0
SM
= 39.04431673 cm3 = 3.90E+04 mm 3
3-2-7/3.5 Longitudinal Bulkhead Webs Webs are to have a section modulus SM as obtained from the following equation. SM = 4.74chsl2Q cm3 c h s l Q
= 1.5 = 4.1895 m = 1.8288 m = 1.4 m =1
SM
= 4.74chsl2Q = 106.7711892 cm 3 = 1.07E+05 mm3
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Actual Scantlings of Bulkhead Stringers and Stiffeners Bulkhead Stringers (T – 250x8 + 100x8) Web
250
Web thickness Flange
8 100
centroid
37.17142857
I0
1.05E+07
Ad2
9.05E+07
Flange thickness
8
IANA
1.01E+08
Plate thickness
8
ITNA
8.16E+07
SM (mm3) Required SM
3.57E+05 1.63E+05
spacing area
1400 14000
Bulkhead Stiffeners (L – 75x75x8) Web
75
centroid
Web thickness Flange
8 75
I0 Ad2
3.10E+05 5.86E+06
Flange thickness
8
IANA
6.17E+06
Plate thickness
8
ITNA
4.56E+06
SM (mm3)
6.10E+04
Required SM
4.56E+04
spacing area
609.6 6076.8
16.29265403
Bulkhead Webs (250x8 FLG. 100) Web Web thickness
250 8
centroid I0
Flange
100
Ad2
9.05E+07
IANA
1.01E+08
ITNA SM (mm3)
8.47E+07 3.60E+05
Required SM
1.07E+05
Flange thickness Plate thickness spacing area
8 8 1828.8 17430.4
30.6431063 1.05E+07
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Moment of Inertia of Sections About Their Own Axes
The neutral axis of a section is initially assumed to be at the unflanged edge of the web portion.
Web thickness
Flange thickness
Centroid
Ad2
I0
IANA
ITNA
Deck girders Deck long'ls Bottom girders
250 75 350
8.5 8 8.5
100 75 100
8 8 8
2925 1200 3775
160.2821 58.25 212.9338
8.48E+07 4.59E+06 1.91E+08
1.11E+07 2.84E+05 3.04E+07
9.59E+07 4.87E+06 2.22E+08
2.07E+07 8.01E+05 5.06E+07
Bottom long'ls
100
8
100
8
1600
77
1.07E+07
6.71E+05
1.13E+07
1.84E+06
Stringers (side + long'l bhd) T-250X8+100X8
250
8
100
8
2800
-
-
-
6.77E+05
Web
Qty
Area
Flange
d
-
i0
Deck girders
6
17550
2639.718
1.24E+08
Deck long'ls
20
24000
2741.75
1.60E+07
Bottom girders
6
22650
212.9338
3.03E+08
Bottom long'ls
20
32000
77
3.67E+07
3
8400
1400
2.03E+06
Stringers (side + long'l bhd) T-250X8+100X8
Area
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Section Modulus Calculation Neutral axis is initially assumed to be at the baseline.
Item
Thickness (mm)
Side shell plating Deck Bottom shell plating Keel Long'l Bulkhead BILGE
Length (one side) (m)
Height (cm)
Length (total) (m)
Area (cm2)
Ad (cm3)
d (cm)
9 7
218.2 0
2.182 6.858
4.364 13.716
392.76 960.12
Ad2 (cm4)
i0 (cm4)
173.38 6.81E+04 1.18E+07 1.56E+06 280 2.69E+05 7.53E+07 0.00E+00
9
6.77
5.5034
11.0068
990.612
3.385
3.35E+03
1.14E+04
3.78E+03
10 8
0 280
0.762
1.524 2.8
152.4 224
0 140
0.00E+00 3.14E+04
0.00E+00 4.39E+06
0.00E+00 1.46E+06
9
60
0.942477796
1.8849556
169.646
38.197186
6.48E+03
2.48E+05
5.78E+05
Deck girders
175.5
263.97179
4.63E+04
1.22E+07
1.24E+04
Deck long'ls
240
274.175
6.58E+04
1.80E+07
1.60E+03
226.5
21.293377
4.82E+03
1.03E+05
3.03E+04
320
7.7
2.46E+03
1.90E+04
3.67E+03
84 3935.538
140
1.18E+04 5.09E+05
1.65E+06 1.24E+08
2.03E+02 3.65E+06
Bottom girders Bottom long'ls Stringers (side + long'l bhd) T-250X8+100X8 Total
true neutral axis = 129.4104008 IANA = 1.2742E+08 ITNA = 6.15E+07 Required I = 5.0540E+07 SMtop = 4.0847E+05 cm SMbottom = 4.7532E+05 cm Required SM = 2.9294E+05
cm cm4 cm4 cm4 3 3
cm3
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