基于三参数可靠性分析模型的随机有限元法

Stochastic Finite Element Method for Reliability Analysis with Geometry Randomness Considered

以三参数可靠性分析模型为基础，建立了一种新的随机有限元模型并导出了全部方程．这一模型全面考虑了载荷、材料性能参数、几何形状等随机因素对结构可靠性的影响。最后以一悬臂梁的可靠度计算为例进行了说明，并与ｏｎｔｅＣａｒｌｏ有限元法以及常规的二参数可靠性分析模型进行了对比。

We now present results of work done on a reliability analysis project supported by theScience Foundation of Aeronautics of China (SFAC). Our project is one of the very fewwhich SPAC has just begun to support. On making preparatiorm for utilizing Wu's three- parameter reliability analysis model[3], we propose a new three- moment stochastic finite element method (TM - SFEM ). Ittalles Into account such random factors as load, material parameters and especially geometry. The randomness of geometry plays a vital role in reliability analysis and its effect can beconveniently computed with eqs. (17) and (18).We take as a numerical example the calculation of the reliability of bending fatiguestrength of a cantilever beam. Numerical results are given in Tables 1 and 2. In these tables IMC- FEM denotes the standard Monte Carlo FEM, and SFEM denotes the normal stochasticFEM. The results indicate that reliability (R) computed with our TM-SFEM is closer to thestandard value computed with MC- FEM.