Section 7 Buckling
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules for the Application of Sandwich Panel Construction to Ship Structure, July 2022 - Chapter 3 Design Basis for Panels - Section 7 Buckling

Section 7 Buckling

Parent topic: Chapter 3 Design Basis for Panels

7.1 General

7.1.1 This Section contains the requirements for buckling control of steel sandwich panels subject to in-plane uni-axial compressive stresses.

7.1.2 In general, all areas of the structure are to meet the buckling strength requirements for the design compressive stresses, see Ch 3, 7.3 Buckling requirements.

7.1.3 The buckling requirements are to be met using the thickness of plating less standard deduction for corrosion, dt , hence any additional thickness for corrosion margin or Owner's extra is not to be included in scantling used to assess the buckling performance.

7.2 Derivation of the buckling stress for steel sandwich panels

7.2.1 The critical compressive buckling stress, σE , for a steel sandwich panel subjected to uni-axial in-plane compressive loads is to be derived as follows:

where
f =
=
µ =
K =
= D, ν, d, tc, Gc , see Ch 1, 7.2 Symbols 7.2.1
l = breadth of panel in the loaded direction, in mm
tp1 = t1 – t corr
tp2 = t2 – t corr
tcorr = standard deduction for corrosion, see Table 4.7.1 Standard deduction for corrosion, d t in Pt 3, Ch 4 of the Rules and Regulations for the Classification of Ships, July 2022.

7.2.2 Where the elastic critical buckling stress, as evaluated from Ch 3, 7.2 Derivation of the buckling stress for steel sandwich panels 7.2.1, exceeds 50 per cent of the specified minimum yield stress of the material, then the buckling stress is to be adjusted for the effects of plasticity using Johnson-Ostenfeld correction formula, given below:

7.3 Buckling requirements

7.3.1 This sub-Section contains requirements for the critical buckling stress for steel sandwich panels exposed to uni-axial compression.

7.3.2 The plate panel buckling requirements will be satisfied if the following is satisfied:

where
σd = design compressive stress.

7.3.3 The design compressive stresses, σd, are to be taken as the global hull girder bending in accordance with Pt 3, Ch 4 Longitudinal Strength of the Rules and Regulations for the Classification of Ships, July 2022. In addition, where the structural member is subject to local compressive loads, then the design stresses are to be based on these loads.

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