随机地震波模拟的时变ARMA方法及VC+ ISML编程实现

Time-varying ARMA method of simulation of random seismic wave and the reliyation of VC+ ISML program

地震模拟波在时程分析、随机地震反应分析、振动台试验以及抗震仿真中应用广泛,使得地面运动的人工模拟成为地震工程中十分重要的研究课题.应用可视化面向对象建模技术构建程序框架,使用VC+ISM L实现新型随机地震波模拟程序W IN S IM.该程序使用考虑幅值和频率双重非平稳性的时变ARM A模型随机地震动模型,用残差的卡方校验对模拟波进行校验,同时程序还提供了功率谱密度图和反应谱图两种辅助定性的校验措施.结果证明,使用该程序生成的地震波,能够精确地反映不同场地条件地震波的频谱和幅值的真实内容.所构建的程序框架的方法,不但提高了软件的可读性和复用性而且方便了专业人员、软件设计人员以及用户之间交流.

The simulated earthquake records are widely used in the random earthquake response, the transient dynamic analysis, the experiment of vibroplatform and the technique of simulation. The object-oriented visual programming technique is used to form the frame of program. The program simulating new type of random earthquake records is made by VC and ISML, which is a modified time-varying ARMA stochastic seismic model, both the amplitude and frequency nonstationarities are incorporated in the model. In this program the sample records reformed by Chinese code 2001 version for seismic design of buildings are used as target earthquake records, and new stochastic seismic model is used to make the simulated earthquake record. Furthermore the Chi-Square verification tests are performed on the different nonstationary ARMA model, and the verification procedures of power density spectrum and response spectrum are given. It shows that the proposed model can reflect accurately the nonstationary features on real earthquake acceierogram, the time-variation of the frequency and the amplitude content.