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为多角度揭示地震对结构的破坏作用,从能量角度研究了单自由度非线性体系的地震响应及其特征.通过Matlab编制了基于双线性滞回模型的单自由度体系地震能量响应分析程序,计算分析了汶川地震波激励下某RC弹塑性结构的能量响应时程及能量占比时程.研究表明,滞回耗能和阻尼耗能是结构耗能主要方式.总输入能和滞回耗能总体递增,而阻尼耗能则单调递增,各能量项在总输入能中的占比主要由滞回耗能控制.结构初始刚度对各项能量响应及其最终占比有重要影响.在某特定刚度值下结构总输入能会达到峰值,且滞回耗能及其最终占比也将达到最大,偏离该特定刚度值两者都将减小.滞回耗能和阻尼耗能的占比时程,在振动初期波动较为剧烈;进入强震阶段后,当初始刚度较小时,两者占比相对稳定,而当刚度较大时,两者占比则有一定波动.“,”In order to reveal the mechanism of earthquake damages of structure in different ways,this paper presents the seismic responses of single degree of freedom nonlinear systems from an energy standpoint.A program for the analysis of seismic energy responses of SDOF systems based on bilinear hysteretic model is implemented using MATLAB.The energy response timehistories and energy proportion time-histories of a RC elastoplastic system under the action of Wenchuan seismic wave are analyzed using the program.The analysis results show that hysteresis and damping are the main means of structural energy dissipation.The overall trend of total input energy and hysteretic energy are increasing,and damping energy dissipation is increasing monotonically.The ratio of each energy response item over total input energy is controlled mainly by hysteretic energy.The structural initial stiffness has an important effect on structural energy responses and the final ratio of each energy response item over total input energy.At a particular stiffness value the total input energy will reach a maximum,and the hysteretic energy and its final ratio will reach a maximum as well.If the stiffness deviates from the particular value,both terms will decrease.The proportion time-histories of hysteretic energy dissipation and damping energy dissipation are violent at the beginning of vibration.In the stage of strong shaking,both energy dissipations are relatively stable given that the initial stiffness is small,and there appear to be a certain fluctuation about the two given that the initial stiffness is large.