基于梯度搜索法的非线性结构可靠性分析方法

很多工程结构具有非线性特征强且功能函数为隐式的特点,以往方法难以精确、高效地分析其可靠性,为此提出一种基于梯度搜索法的强非线性结构可靠性灵敏度分析方法.根据工程结构的隐式功能函数,利用差分法计算初始抽样点附近的梯度信息;基于验算点梯度搜索法,获得与抽样点对应的距极限状态曲面距离最小的极限状态点,过该点依据Taylor展...

An Analysis Method for Nonlinear Structural Reliability Based on Gradient Search Method

Many engineering structures have strong nonlinear characteristics and their functions are implicit. It is difficult to analyze the reliability of engineering structures accurately and efficiently. A sensitivity analysis method of strong nonlinear structural reliability based on gradient search method is proposed. Based on the implicit function of engineering structure, the gradient information near the initial sampling point is calculated by using the difference method. Then the gradient search method of checking point is used to obtain the limit state point at the minimum distance from the limit state surface corresponding to the sampling point, through which the limit state surface is linearly expanded by Taylor expansion method. A set of training samples near the limit state surface are obtained through several iterative searches. On this basis, the polynomial function and response surface function are used to fit the limit state equation to calculate the reliability and reliability sensitivity. The numerical and engineering examples show that the proposed method has the advantages of high accuracy and less sampling times compared with the previous methods, and it is suitable for the reliability analysis of strong nonlinear implicit structures.