基于改进响应面法的桁架结构的可靠性分析

Reliability analysis of truss structure based on improved response surface method

在对现有结构可靠度计算方法进行深入研究的基础上,文中提出了一种结构可靠度计算方法,以便能将桁架结构可靠度分析更加高效。这种分析方法是通过改进的响应面法进行的,旨在减少桁架结构可靠度计算中涉及的计算工作量,并利用APDL命令流对桁架结构进行建模。在不能或难以获得功能函数与其变量之间明确表达式的复杂结构中,应用Matlab-Ansys数据交互寻找一个合适的、能够近似等于原始功能函数的显式功能函数式(RSF)代替原始的、近似隐式的功能函数(LSF),获得显式功能函数式(RSF)后分别使用Ansys中PDS模块的蒙特卡洛法-响应面分析法(MCS-RSM)混合模拟法和遗传算法(GA)进行迭代计算可靠性指标和设计点,并以桁架结构为算例进行分析比较。结果表明:使用Matlab-Ansys数据交互较易获得显式功能函数式(RSF),遗传算法(GA)可将计算效率提高95%以上。

Based on the in-depth study of the existing structural reliability calculation methods,in this paper,a structural reliability calculation method is proposed to improve the reliability analysis efficiency of truss structures.This analysis method works relying on the improved response surface method and aims to reduce the calculation workload of truss structure reliability,and uses APDL command flow to model the truss structure.In the complex structure where it is impossible or difficult to obtain the explicit expression between the function and its variables,an appropriate explicit function formula(RSF)which can be approximately equal to the original function is found by Matlab-Ansys data interaction,and the explicit function formula(RSF)was obtained,and then the Monte Carlo method-response surface analysis(MCS-RSM)hybrid simulation method and genetic algorithm(GA)of PDS module in Ansys were used respectively.The results show that it is easy to get explicit function formula(RSF)through Matlab-Ansys data interaction,and genetic algorithm(GA)can improve the calculation efficiency by more than 95%.