Nonlinear Response Spectrum of SMA Self-centering System
Liu Jin-long;Institute of Engineering Mechanics,China Earthquake Administration,Key Laboratory of Earthquake Engineering and Engineering Vibration;
In this paper,the research status of nonlinear seismic response spectrum is summarized first. The SMA material and selfcentering system based on this material are introduced,and the basic theory of nonlinear spectrum is reviewed. The typical earthquake records are selected using genetic algorithm,and the analysis conditions are designed according to characters of hysteretic loop of SMA self-centering system. Then the accurate nonlinear seismic responses of SMA self-centering system are calculated using numerical simulation method. Based on the simulation results,the model parameters of nonlinear response spectrum for flag hysteretic loop are regressed by least square method. At last,the calculated curves from regressed model are compared with the accurate nonlinear seismic responses,and the results prove that the regressed model has enough accuracy for the nonlinear design of self-centering system with flag shape hysteretic loop.