A Study on Reliability Assessment of Plate Structures Based on Collapse Mode Analysis

本文研究了基于倒塌模态分析的板梁组合结构的可靠度评估。本文的研究结果总结如下：1。本文提出了一种新的板单元，用于有效、准确地分析薄壁结构，如由许多初始缺陷的加筋板组成的海洋结构，采用大挠度和截面屈服条件下的选择性特征函数。提出了一种新的板梁组合单元体系，扩大了基于结构可靠性的灵敏度分析与倒塌模态分析相结合的适用性。通过纵向加劲箱梁的数值算例，验证了该系统的适用性。应用该系统研究了某型高速集装箱船在航向和斜海条件下的结构可靠性和灵敏度特性。以斜海条件下船体结构后L/4部分为例，分析结果表明，面内扭转剪应力对包括内壳单元中部损伤在内的主导破坏模式的影响是主要的。这些特征与前人的研究结果吻合较好。

This study is concerned with the reliability assessment of combined plate and beam structures based on collapse mode analysis. Results obtained in this study are summarized as follows :1. A new plate element is developed for efficiently and accurately analyzing thin walled structures such as marine structures composed of many stiffened plate panels with initial imperfection, using selective eigen-functions for large deflection and sectional yield conditions.2. A new system using combined plate and beam elements is presented to offer the expansion of the applicability of the structural reliability-based sensitivity analysis combined with collapse mode analysis.3. The applicabiity of the proposed system is demonstrated through a numerical example applied to a simple box girder with longitudinal stiffeners.4. Features of the structual reliability and sensitivity factors of a high speed container ship under heading and oblique sea conditions are also investigated by applying the newly developed system.5. The analytical result, e.g., for the aft L/4 part of the hull structure under the oblique sea condition shows that effects of in-plane shearing stresses due to torsional moment on the dominant collapse mode including damages of the middle part of the inside shell elements are dominant. These features are good correspondent with results in previous researches.