关于虚拟激励法与结构随机响应的注记

虚拟激励法自发表以来，引起了学术界和工程界的较大关注。特别是在处理大型复杂结构受多点随机激励时，该法自动计及了参振振型的互相关以及激励之间的互相关，在理论上是精确解。而且该法对于处理非经典阻尼矩阵很方便，在一般具有简谐振动／时程分析功能的有限元程序上进一步开发计算位移，内力，应变等各种平稳／非平稳响应量的自谱互谱计算功能都十分方便，所以获得了较多应用。对该算法的适应性和计算效率与传统算法明确地给出对比，将对其理解与推广应用有很大好处。本文将对此作一些说明。

Some notes on FEM and structural random response analysis

The Pseudo Excitation Method (PEM)has received much attention due to its outstanding advantages. It is highly efficient and necessarily involves the cross correlation terms both between the participant modes and between the excitations; so that it is theoretically exact. In addition, it is very easy to develop the analysis functions of structural stationary or non stationary random reponse on any FEM program with the function of harmonic or time history analysis. This article compares the efficiency and adaptability between PEM and the conventional method in order to make PEM be better understood and applied.