应用随机过程的正交展开-随机函数方法,建立了非平稳地震动过程的概率模型,实现了用一个基本随机变量来表达地震动过程的目的。通过选取基本随机变量的代表性离散点集,可以直接获取地震动过程的代表性样本集合。结合概率密度演化理论,进行了多自由度Duffing系统的随机地震反应分析与抗震可靠度计算。研究表明,非平稳地震动过程的概率模型与概率密度演化理论有机结合,可以实现复杂工程结构整体抗震可靠度的精确计算。 The probability model of non-stationary ground motion process is established by orthogonal expansion-stochastic function method of stochastic process. The purpose of expressing ground motion process by a basic random variable is achieved. By selecting the representative set of discrete points of the basic random variables, a representative set of samples of the ground motion process can be obtained directly. Combined with the theory of probability density evolution, random seismic response analysis and seismic reliability calculation of multi-degree-of-freedom Duffing system are carried out. The research shows that the probability model of non-stationary ground motion and the theory of probability density evolution can be combined organically to accurately calculate the overall seismic reliability of complex engineering structures.