桁架结构随机有限元的可靠性分析

Reliability Analysis of Stochastic Finite Element Method for Truss Structures

研究基本随机变量对结构可靠性的影响,针对桁架结构分别或同时考虑了结构的物理参数、构件的几何参数以及作用荷载等的随机性,提出了将确定性有限元随机化的方法,结合H-L(Hasofer-Lind)几何法,分别以结构的位移与应力响应作为功能函数,得到结构中构件的最小可靠指标。通过算例表明随机变量的变异系数对构件可靠指标有较大影响,当同时考虑多个基本随机变量时,结构响应呈现出很强的随机性,基于随机有限元的可靠性分析方法具有一定普适性、可行性与实用性。

The effects of basis random variable on structure reliability are studied in this paper.The method brought forward is to change the determinate method to the stochastic finite element by synchronously or respectively considering the physics parameter,geometry parameter and random loading.Using H-L geometry method,the minimum credibility index has been gotten by using structure displacement and stress response as function.The results show that the variation coefficient of random variable has very large effects on structure credibility index.When muti-basis random variables are considered,construction response represents strong stochastic.This example reveals that the method has feasibility,rationalization and practicability.