1、AMERICAN BUREAU OF SHIPPING one within the midship region and another at the region of high shear forces. The collision damage is assumed to be located at the upper pari of the side shell, down from (and including) the stringer plate of the strength deck. The following members should be assumed to b
2、e damaged and excluded totally or partially, from the hull girder section modulus calculation (see Fig. 2). side shell plating for the vertical extent of 4 m or D/4, (designated as “h“ in Fig. 2), whichever is greater, down from the upper edge of the sheer strake, where D is the ship depth as define
3、d in 3/15 of the Rules. strength deck plating including the stringer plate to the extent from the side shell to the inner skin. Slope bulkhead plating, side stringers and diaphragms in the upper wing tanks, within the damaged zone for the extent of 0.5% of the vertical extent of the damaged side. al
4、l deck, side and other longitudinals and longitudinal stiffeners attached to the damaged plating. 5.0 RESIDUAL STRENGTH ASSESSMENT The assessment is to demonstrate that the appropriate residual longitudinal strength of the hull girder after an accident as specified in 2.0 is in compliance with the s
5、trength criteria given in 7.0 for a single trip from the site of accident to a repair yard under load conditions as specified in 6.0. The residual 2 ABS #78 95 = Ob53302 0033773 889 M K“S Hogging Kuw Ku, Sagging KU, hull girder section modulus may be calculated using either a finite element model or
6、 a simplified method based on the assumed damage, as given in 3.0 or 4.0. The residual bending strength should be analyzed for both collision and grounding situations. The residual shearing strength should be checked for collision, but need not be analyzed for grounding. O Grounding Collision 1.1 1
7、.o 0.5 0.7 0.9 1 .o 0.5 0.7 6.0 LOAD CRITERIA Residual strength of the damaged hull-girder should be assessed based on the total longitudinal bending moments, M, and shear forces, F, given as follows: kN-m (tf-m, Ltf-ft) kN (tf, Ltf) where M, F, - maximum still-water bending moment (hogging andlor s
8、agging) and shear force (positive andlor negative), in intact condition. M, Fw = wave-induced vertical longitudinal bending moments (hogging and sagging) and shear forces (positive and negative), calculated in accordance with 5/3A.3.3 of the Rules. O Ku, and Ku, are given in the following table. Bot
9、h hogging and sagging conditions are to be considered. Local loads for secondary and tertiary bending need not be taken into consideration. 3 ABS #8 75 E Ob51102 0013774 715 = Width of damage 4m or 0/6 whichever is greater Figure 1 Y- - r r r Figure 2 4 ABS #?8 95 Ob53302 0033775 651 7.0 RESIDUAL ST
10、RENGTH CRITERIA 7.1 Residual Bending Strength Criterion The residual section moduli of the damaged hull-girder, calculated in accordance with 513A4.2.1 of the Rules excluding the nominal design corrosion values and the damaged O members as specified in 3.0 and 4.0, are not to be less than the nomina
11、l section modulus: SM, = 0.9 MjfP cm2 - m(in.2 - fi) where M, is the total longitudinal bending moment as specified in 6.0. f, is the nominal permissible bending stress as specified in 316.3.4 of the Rules. 7.2 Residual Shearing Strength Criterion The shear stresses, f, in the side shell plating, af
12、ter damage due to a collision, are not to be greater than that given by the formula: fsr = n, n2 F, m(Ihs) 5 1.1 f, kN/cm2(tf/cm2, Ltf1in.2) where F, = total shear force as specified in 6.0 t, = thickness of side shell plating in cm (in.) f, = permissible shear stress specified in 512A4.2.3 of the R
13、ules. m, and I, are the first moment, in cm3 (in3), and moment of inertia, in cm4 (in4), of the “net“ hull-girder damaged due to a collision at the station being considered. n, = A,2(Asd + A, + 0.5Ai) n2 = D/(D-h) A, = residual shell plating area of the damaged side, in cm2 (in2). A, = total plating area of one side shell (outer skin), in cm2 (in2). A, = total plating area of one outermost longitudinal bulkhead (inner skin), in cm2 (in2). Ai = total plating area of all other longitudinal bulkheads between the inner skins, in cm2 (in2). D and h are as defined in 2.0.
