A Study on Reliablility Assessment of Plate Structures Based on Ultimate Strength Analysis

本文研究了由空间核单元组成的薄板结构和船体梁在静载荷和极端波浪载荷联合作用下的极限强度和可靠性分析，其中单元的线性化失效条件是最佳的，它考虑了平面应力条件下的屈服和屈曲破坏。该失效准则便于安全裕度的生成和失效概率的计算。结构失效被定义为由于倒塌而产生的大变形。采用所谓的bmh和界限方法来选择概率上占主导地位的失效模式，节省了对大型结构进行可靠性分析的共同努力。最后，本文以一艘油船和一艘散货船的船体梁为研究对象，分别计算了在两种载荷作用下的工字型圆柱体和理想化的空间结构。通过数值算例与船体梁模型研究结果的对比，验证了本文方法的适用性。

This study is concerned with the ultimate strength analysis and reliability analysis of thin plate structures and ship's hull girder, which ar-e comm of the spatial nubrane elements and subjected to combined static loads and extreme wave loads.The linearized failum condition of an element is firest in&Wuced, which takes accomt of the yielding and buckling collapse under the plane stress condition. The failure criterion facilitates the generation of safety margins and the calculation of failure probabilities.Structural failure is defined as the generation of large deformation due to collapse.The socalled bmh-and-bound method is applied to select the probabilistically dominant failure modes, which saves the commbicnal efforts to perform a reliability analysis on large-scale structures.Finally, the proposed methods are applied to a I cylinder under lateral loads &id spatial structures idealized for wdeling maln hull girders of an oil tanker and a bulk carrier under two loading conditions. Through comparison between numerical examples and research results due to hull girder models, the applicability of proposed methods is dewnstmted.