考虑场地介质随机特性的无限域波动分析  

INFINITE DOMAIN WAVE MOTION ANALYSIS IN RANDOM MEDIA

作　　者：廖松涛[1] 李杰[1] 

机构地区：[1]同济大学建筑工程系,上海200092

出　　处：《力学学报》2003年第2期199-205,共7页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家杰出青年基金资助项目(59825105).

摘　　要：针对场地介质具有随机特性的无限域地震波动分析问题,在概率空间中将随机反应向量按随机介质场离散所得主导随机变量的正交多项式级数形式展开,使随机微分方程变换为确定性的扩阶线性方程组;并在波动有限元模拟技术的基础上,构造了扩阶透射人工边界公式,两者结合形成了求解无限域随机介质中波动传播问题的有限元分析方法.该方法不仅不受基于摄动思想各类方法的久期项的干扰,而且避免了采用模拟方法时人工边界区单元参数样本不均匀所引起的数值计算不稳定问题.The random parameter field is discretized into random variables which are expanded in the form of orthogonal polynomials in probability space, and the random differential wave equation is transformed into deterministic linear order-expanded equations. An order-expanded multi-transmitting artificial boundary formula is also derived based on the finite element simulation of wave motion. The combination of the deterministic order-expanded equations and the order-expanded multi-transmitting artificial boundary formula can provide a method to analyze the problem of wave motion analysis in infinite domain with uncertainty in site. Not only is this method free from the secular problem of the corresponding methods which are based on perturbation idea, but also it avoid the numerical instability resulted from the heterogeneity of the ABC elements samples when the Monte Carlo simulation method is used.

关 键 词：无限域波动分析 随机介质 有限元分析 扩阶透射人工边界 MONTECARLO模拟 地震 

分 类 号：P315.31[天文地球—地震学]