非高斯结构首次超越分析的概率模型  

Probabilistic model for the first passage of Non-Gaussian structures

作　　者：何军[1] 寇新建[1] 

机构地区：[1]上海交通大学船建学院土木工程系,上海200240

出　　处：《计算力学学报》2007年第1期64-68,共5页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金资助(50478017)

摘　　要：利用Fleishman近似,通过非高斯结构动力响应的前四阶中心矩,将分布未知的结构响应过程变换为标准高斯随机过程,提出非高斯结构动力响应的平均穿越率计算公式,并考虑初始条件和群穿尺寸的影响,修正平均穿越率的计算,在此基础上,利用传统Poisson模型,建立非高斯结构首次超越分析的概率模型。算例分析表明,本文提出的概率模型可以在结构随机振动分析或试验与检测数据的基础上,分析非高斯结构的首次超越问题,并克服了传统高斯模型所固有的诸多缺点。Using the Fleishman approximation based on first four response moments of Non-Gaussian structures, the structural responses without complete probability information are transformed into standard Gaussian processes in the paper. And then the formula estimating the mean up-crossing rate of the structural responses is proposed, which can be modified by the initial condition, band width and clump size. Based on the traditional Poisson model, the probabilistic model for the first passage of Non-Gaussian structures is formulated in the paper. Numerical examples show that the model can be used to study the problem of the first passage of Non-Gaussian structures through only first four response moments. Numerical examples also show that the model can overcome the problems, such as conservative failure probability and need of complete probability information of structural responses, inherent in the traditional Gaussian model.

关 键 词：非高斯结构 首次超越 Fleishman近似 平均穿越率 失效概率 

分 类 号：TU311.4[建筑科学—结构工程]