摘要
演变随机过程是指平稳随机过程按确定性调制规律演化而得的一种非平稳随机过程。无论是时不变或时变系统在演变随机激励下的响应 ,还是时变系统在平稳随机激励下的响应 ,均属演变随机响应。求解演变随机响应问题的关键在于找到该响应的确定性调制规律。最近提出的线性系统的演变随机响应问题的统一解法指出 :求解有关演变随机响应的调制规律等价于求解原系统在某种确定性激励下对应于零初始条件的瞬态响应。在一般情形下 ,这类瞬态响应均可用现成的数值解法 ,例如 Runge- Kutta法求得。上述统一解法原本是针对确定性系统提出的 ,但结合 Monte- Carlo法、或随机摄动法、或随机正交展开法 ,就可推广用于随机结构的演变随机响应分析 。
An evolutionary random process is a non stationary process, obtained by deterministically modulating a stationary random process. There are two typical evolutionary random excitations in engineering. One may be generated from filtering a stationary random process through a time variant system. The other may result from nonlinear transformation of the argument of a stationary random process. No matter whether the system is time variant or time invariant, their responses to evolutionary random excitations are also evolutionary random processes. The key to the evolutionary random response problem lies in extracting the modulating function of the response. Being found as a kind of transient response under zero initial conditions of the original system subject to a certain deterministic excitation,the wanted modulating function of the evolutionary random response can be obtained by any available numerical methods,such as the Runge Kutta method. Although being suggested originally for deterministic linear systems,by combined with the Monte Carlo method,or the stochastic perturbation method,or the orthogonal expansion method,the unified approach to evolutionary random response problems can also be applied to random structures as well.
出处
《振动工程学报》
EI
CSCD
北大核心
2002年第3期290-294,共5页
Journal of Vibration Engineering
关键词
结构动力学
随机振动
时变系统
随机结构
演变随机响应
structural dynamics
random vibration
time variant system
random structure
evolutionary random response
