二维土-结构地震动力相互作用时域有限元分析

土与结构动力相互作用是地震工程研究中的一个十分重要的课题。给出了分析地震作用下二维土-结构动力相互作用的时域有限元方法。重点放在如何模拟瞬态波在无穷介质中的传播以及如何实现地震动的输入方面。在给出的有限元过程中,地震动的输入方法以及用于截断无穷介质以获得有限计算域的局部透射人工边界都是基于柱面波动方程推导建立的,这种方法非常简单有效,结合Newmark时间积分法是无条件稳定的,使得时域计算有效而可靠。数值算例验证了这种方法的精度和有效性。

TIME-DOMAIN FINITE-ELEMENT ANALYSIS OF TWO DIMENSIONAL SEISMIC SOIL-STRUCTURE INTERACTIONS

The dynamic soil-structure interaction(SSI)is one of the most important subjects in earthquake engineering.A time-domain finite element method(FEM)for analysis of two dimensional dynamic soil-structure interactions due to seismic excitations is presented.Emphasis is placed on how to simulate transient wave propagation in unbounded media and how to realize the earthquake input.In the proposed finite element procedure,both the method for earthquake input and the local transmitting artificial boundaries for finite analysis domain are established based on the cylindrical wave equation.The proposed method is simple and efficient,and the time-stepping scheme using Newmark's method in conjunction with the method is unconditionally stable,allowing for efficient and reliable time-domain computations.Numerical examples are presented to illustrate the validity and accuracy of the proposed method.