ABSTRACT

The main objective of this study is to investigate the effect of non-uniform thickness reduction and model selection on the predicted ultimate strength of stiffened panels under longitudinal compression. Random fields theory is used to describe the two-dimensional variation of thickness over the plates’ surface. Non-Gaussian sample functions are thus generated using the spectral representation method in combination with translation fields, whereas Monte Carlo simulation is employed to compute the response statistics. The paper provides an insightful guide for the implementation of stochastic finite element method (SFEM) into a deterministic FE software such as Abaqus. The evaluation of stiffened panel's ultimate strength variation due to the described inherent uncertainties of thickness and model selection, namely, the CSR load-end shortening curves analytical relations versus SFEM, is implemented. The results revealed that the uniform thickness approach of CSR using the net-50 scantlings provides a reasonable conservatism on the predicted ultimate strength.

摘要

本研究的主要目的是研究非均匀厚度减少和模型选择对纵向压缩下加筋板的预测极限强度的影响。随机场理论用于描述板表面厚度的二维变化。非高斯样本函数因此使用谱表示方法结合平移场生成，而蒙特卡罗模拟用于计算响应统计。该论文为在 Abaqus 等确定性有限元软件中实施随机有限元法 (SFEM) 提供了深刻的指导。由于所描述的厚度和模型选择的固有不确定性，对加筋板的极限强度变化的评估，即，CSR 负载端缩短曲线与 SFEM 的解析关系得到实施。结果表明，使用净 50 尺度的 CSR 均匀厚度方法为预测的极限强度提供了合理的保守性。