结构平稳随机地震反应时域分析:应用

以平面框架结构为例阐述了结构平稳随机地震反应时域分析方法的应用。首先利用静力凝聚方法大幅度地缩减结构的自由度数目，形成一维链状模型，使得结构运动方程中只包含各层反应从而大大降低计算工作量。其次推导了结点随机反应和层间随机反应的计算公式，可以方便地获得结构在理想白噪声、金井清谱和改进金井清谱三种随机地震地面运动激励下的协方差位移反应函数和协方差速度反应函数。最后通过一个单跨双层的平面框架结构实例，阐述了这种方法的使用过程。

Random seismic response analysis of structures in time domain:application

The plane frame structure is utilized to illustrate the application of the random seismic response analysis method of linear structures in time domain, which was developed in reference 1. Firstly, a static condensation technique is used to simplify the frame structure to a stick model with lumped mass at each floor level, and the degrees of freedom are reduced greatly in the process of structural analysis. Only the story responses are retained in the equation of motion of the structure under a seismic excitation so that the computer efforts are descended enormously. Then the covariance response matrixes of nodal displacements and the story drifts are deduced, and the mean square responses of the structure, including the displacement responses and the velocity responses, can be obtained directly subjected to the ground motion represented by the Gaussian white noise process, the filtered Gaussian white noise process with the Kanai-Tajimi power spectrum and the twice filtered Gaussian white noise process with the modified Kanai-Tajimi power spectrum from the solved covariance matrixes. Finally an one-span two-story plane frame structure is analyzed in detail for numerical illustration of this method.