Clasification Society Rulefinder 2020 - Version 9.33 - Fix
Common Structural Rules - Common Structural Rules for Bulk Carriers and Oil Tankers, January 2019 - Part 1 General Hull Requirements - Chapter 5 Hull Girder Strength - Appendix 2 Hull Girder Ultimate Capacity - 1 General

1 General

1.1 Application

1.1.1 This appendix provides the criteria for obtaining the following ultimate longitudinal bending moment capacities:
  • MU to be used in the hull girder ultimate capacity check according to Ch 5, Sec 2,
  • MUD to be used in the hull girder residual strength capacity check according to Ch 5, Sec 3

1.1.2 The hull girder ultimate longitudinal bending moment capacity, MU or MUD, is defined as the maximum bending capacity of the hull girder beyond which the hull structure collapses. Hull girder failure is controlled by buckling, ultimate strength and yielding of longitudinal structural elements.

1.2 Methods

1.2.1 Incremental-iterative method

The hull girder ultimate bending capacity is to be assessed by the incremental-iterative method defined in [2].

1.2.2 Alternative methods

Principles for alternative methods for the calculation of the hull girder ultimate bending capacity; e.g. nonlinear finite element analysis, are given in [3].

Application of alternative methods is to be agreed by the Society prior to commencement. Documentation of the analysis methodology and detailed comparison of its results are to be submitted for review and acceptance. The use of such methods may require the partial safety factors to be recalibrated.

1.3 Assumptions

1.3.1 The method for calculating the ultimate hull girder capacity is to identify the critical failure modes of all main longitudinal structural elements.

1.3.2 Structures compressed beyond their buckling limit have reduced load carrying capacity. All relevant failure modes for individual structural elements, such as plate buckling, torsional stiffener buckling, stiffener web buckling, lateral or global stiffener buckling; and their interactions, are to be considered in order to identify the weakest inter-frame failure mode.

1.3.3 Only vertical bending is considered. The effects of shear force, torsional loading, horizontal bending moment and lateral pressure are neglected.

1.3.4 For the calculation of the ultimate longitudinal bending moment capacity, MUD, used in the hull girder residual strength check according to Ch 5, Sec 3, the structural members in way of the damage part are to be excluded from the members participating to the considered cross section strength.

Parent topic: Appendix 2 Hull Girder Ultimate Capacity
Copyright 2020 Clasification Society, International Maritime Organization, International Labour Organization or Maritime and Coastguard Agency. All rights reserved. Clasification Society, its affiliates and subsidiaries and their respective officers, employees or agents are, individually and collectively, referred to in this clause as 'Clasification Society'. Clasification Society Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Clasification Society entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract.