结构可靠度分析的混合法

介绍一种新的计算结构可靠度方法———混合分析法。该方法利用响应面法将极限状态方程近似表达为简单的多项式形式,有效地解决了FORM和SORM无法求解隐式极限状态方程的可靠度问题。另外,响应面法的使用还能有效地利用现有的确定性分析软件。通过引入有限元方法,混合分析法可适用于结构可靠度问题。通过使用重要抽样技术,提高了混合分析法的计算效率和计算精度。数值算例验证了混合分析法的应用、效率和精度。

A Mixed Method for Reliability Analysis of Structures

A mixed method for calculating reliability index is presented in this paper through combination of the advantages of the response surface method (RSM),finite element method (FEM),first order reliability method (FORM) and the importance sampling updating method.Using the RSM method combined with FORM,the mixed method can calculate the reliability of complex structures of which the limit state functions are not known explicitly.Also,it is possible to use the existing deterministic finite element code without modifying it.By introducing the FEM,the mixed method is extended to perform finite element reliability analysis.The efficiency and accuracy of the mixed method are improved by the use of the important sampling updating technique.The applicability,efficiency and accuracy of the mixed method are verified by numerical examples.