半无限介质多自由度频响函数离散时间有理近似的稳定参数识别  

IDENTIFICATION OF STABLE PARAMETERS FOR DISCRETE-TIME RATIONAL APPROXIMATION OF MDOF FREQUENCY RESPONSE FUNCTIONS IN SEMI-INFINITE MEDIA

作　　者：李鑫[1] 唐贞云[1] 杜修力[1] LI Xin;TANG Zhen-yun;DU Xiu-li(The Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点试验室,北京100124

出　　处：《工程力学》2024年第8期1-10,共10页Engineering Mechanics

基　　金：国家自然科学基金项目(51978016)。

摘　　要：离散时间有理近似函数是将半无限土频响函数转化为时域模型的重要工具,离散时间有理近似函数和时域模型具有相同的稳定性和精度。目前关于离散时间有理近似函数的研究只针对于单自由度系统。该文基于线性控制理论,给出了多自由度有理近似系统的稳定条件。将稳定性条件与遗传-序列二次算法相结合,开发了多自由度频响函数参数辨识方法,保证了多自由度系统的稳定性和精度。不同维度的多自由度有理近似系统的数值仿真验证了该文方法可以保证多自由度有理近似系统的稳定性和精度。The discrete-time rational approximation(DRA)function is an important tool to convert the frequency response function of semi-infinite soil into a time-domain model.The DRA function has the same stability and accuracy as the time-domain model.Current studies on DRA function focus only on single-degree-of-freedom system.In the paper,stability conditions for rational approximate systems with multiple degrees of freedom(MDOF)based on the linear control theory is provided.In combination with the stability condition with the genetic-sequential quadratic algorithm,a parameter identification method for frequency response function of MDOF systems is developed,which ensures the stability and accuracy of the MDOF system.Numerical simulation for the rational approximation of MDOF systems with different dimensions shows that the proposed method can guarantee the stability and accuracy of rational approximation for MDOF systems.

关 键 词：离散时间有理近似函数 多自由度 参数识别 稳定性 精度 

分 类 号：TU470[建筑科学—结构工程]