多维地震作用下偏心结构动力反应的Simulink仿真分析

Dynamic Response Analysis of Eccentric Structure to Multi-Dimensional Earthquake Motions Using SIMULINK

理论研究与震害经验表明,地震时结构会产生不可忽略的平动与扭转耦合的空间振动,因此,对结构进行平—扭耦联反应分析具有重要意义。本文首先建立多维地震动作用下偏心结构的空间力学模型和动力方程,并编制相应的MAT LAB程序,然后将动力方程所代表的动力学系统用控制理论中的状态空间法予以描述,根据其状态方程在SIMULINK环境下建立仿真分析模型,从而求解动力方程。对一双向水平地震作用下的6层偏心框架结构进行平—扭耦联反应数值仿真分析,得出了一些有益的结论。

Theoretical research and earthquake damage investigation have shown that there is un-negligible spatial vibration resulting from coupled translation and torsion responses of structures when earthquake occurs. Main reasons are due to facts that both structures are unsymmetrical and seismic ground motions are of multiple components including rotational components. Sometimes the twist damage of structure is predominant during seismic motion. Thus, it is quite significant to take this coupling effect into account in structural dynamic response analysis. Firstly, spatial mechanical model and dynamic equation of the eccentric structure are established in this paper, and corresponding Matlab programs are compiled to solve the corresponding formulas. And then, the dynamic system represented by the dynamic equation is expressed by the state space method. According to the state equation, an emulative model is built using Simulink in Program Matlab so that the dynamic response can be obtained. The coupled translational and torsional responses of a six story frame structure with bilateral eccentricities under the action of two-way horizontal seismic ground motions are investigated by applying the earthquake records: El Centro, Taft and Seattle waves. The effects of eccentric ratio of structure on the coupled translational and torsional responses of structure subjected to multiple ground motions are discussed and some conclusions with engineering significance are drawn.