一种基于凸集-概率混合模型的结构可靠性分析法  

A Method for Structural Reliability Analysis Based on the Convex Set-probability Hybrid Model

作　　者：贾大卫 吴子燕[1] 何乡 Dawei Jia;Ziyan Wu;Xiang He(School of Mechanics,Civil Engineering and Architecture,Northwestern Polytechnical University,Xi’an,710129)

机构地区：[1]西北工业大学力学与土木建筑学院,西安710129

出　　处：《固体力学学报》2020年第5期470-484,共15页Chinese Journal of Solid Mechanics

基　　金：国家自然科学基金项目(51708545,51278420)资助。

摘　　要：论文建立一种凸集-概率混合模型下的结构可靠性分析方法.考虑椭球模型和区间模型两种不同类型的凸集模型,在标准空间内通过拉丁超立方抽样生成样本点,通过矩阵变换将其转换到凸集空间内,得到凸集变量的样本点;将凸集变量样本点代入极限状态方程,从而混合可靠性模型转变为纯概率可靠性模型;利用Laplace渐进积分法对每个极限状态方程进行失效概率求解,统计结果的最大值和最小值,得到失效概率的上、下界,研究了凸集变量的个数对结果的影响,通过失效概率的变异系数描述计算结果的稳定性;通过三个算例验证了计算结果的精度,并采用混合模型的蒙特卡洛法进行对比计算.研究表明:论文所提方法计算精度和效率均较高;凸集模型的类型会对结果产生较大影响;为使结果趋于稳定,椭球模型所需的凸集样本点个数多于区间模型;若凸集样本点数目相同,椭球模型的失效概率计算结果变异系数较小,稳定性高于区间模型.Because the reliability method under probability theory cannot consider the problem of convex set model with incomplete information, this paper establishes a method for reliability analysis under the convex set-probability hybrid model based on sampling and the Laplace progressive integral method. Two different types of convex set models are considered, including an ellipsoidal model and an interval model. Latin hypercube sampling is used to generate sample points in the standard space, which are then transformed into the convex set space by matrix transformation, and the sample points of convex set variables are obtained. These sample points are substituted into the limit state equation, so that the hybrid reliability model is transtormed into the probabilistic reliability model. The Laplace progressive integration method is used to solve the failure probability of each limit state equation. The maximum and minimum values of the results are calculated, and the upper and lower bounds of the failure probability are obtained. The coefficient of variation of the failure probability is used to describe the stability of the calculation result. The accuracy is verified by three examples, the influence of the number of sample points of convex set variables on the result is discussed, and the comparison calculation is carried out by the Monte Carlo method under the hybrid model. The research shows that the method proposed in this paper has high accuracy and efficiency;and is also applicable to the reliability problems with small failure probability. When the upper and lower bounds of the convex set variables are the same, the results obtained by the interval model and the ellipsoidal model are different. In order to stabilize the results, the ellipsoidal model requires more convex set sample points than the interval model. If the interval model is used, the number of sample points should be more than 3000. With the same number of sample points in the convex set, the coefficient of variation of the failure probability cal

关 键 词：凸集-概率混合模型 可靠性分析 矩阵变换 Laplace渐进积分法 变异系数 

分 类 号：TB114.3[理学—概率论与数理统计]