Abstract This paper introduces a novel analytical method to predict the buckling collapse behaviour of a ship hull girder subjected to several cycles of extreme load. This follows the general principles of the established simplified progressive collapse method with an extended capability to re-formulate the load-shortening curve of structural components to account for cyclic degradation. The method provides a framework for assessing residual hull girder strength following a complex series of unusually extreme load events where the wave induced bending moment rises close to, or even surpasses, the monotonic ultimate strength. These load events may be sequential, such as might be caused by a series of storm waves, or they may occur as a collection of discrete events occurring over a longer period. The extreme cyclic bending amplifies the distortion and residual stress initially induced by fabrication in the flanges of the girder, which results in a deterioration of the residual ultimate strength. Validation is firstly completed through a comparison with previously published experimental work and secondly via comparison with numerical simulation on four ship-type box girders using the nonlinear finite element method.

中文翻译：

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极端循环弯曲作用下船体梁的渐进倒塌分析

摘要 本文介绍了一种新的分析方法来预测船体梁在多次极端载荷循环下的屈曲倒塌行为。这遵循已建立的简化连续倒塌方法的一般原则，具有重新制定结构部件的载荷-缩短曲线以解决循环退化的扩展能力。该方法提供了一个框架，用于在一系列复杂的异常极端载荷事件之后评估剩余船体梁强度，其中波浪引起的弯矩上升到接近甚至超过单调极限强度。这些负载事件可能是连续的，例如可能由一系列风暴波引起，或者它们可能作为在较长时期内发生的离散事件的集合而发生。极端循环弯曲放大了最初由梁翼缘制造引起的变形和残余应力，导致残余极限强度下降。验证首先通过与先前发表的实验工作进行比较，其次通过使用非线性有限元方法对四个船型箱梁的数值模拟进行比较。