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研究了在输入地震动加速度反应谱与峰值速度不变的条件下,地震动峰值位移对单自由度体系(SDOF)动力反应、尤其是非线性动力反应的影响。首先,利用在时域内叠加窄带时程的方法合成出加速度反应谱与峰值速度相同、但峰值位移相差2倍的两组人工地震动时程。其次,利用理想弹塑性SDOF体系的初始自振周期描述其刚度特性、利用屈服强度衰减因子描述其非线性力学行为的发展程度,通过比较体系在上述两组输入地震动作用下地震反应的差异,揭示了地震动峰值位移对体系弹塑性地震反应的影响规律:当结构非线性力学行为得以充分发展时,在输入地震动的反应谱与峰值速度相同的情况下,其峰值位移的增大将会显著增加较长周期结构的弹塑性速度与位移反应,而且这种增大效应对于位移反应而言更为显著。
The effect of peak ground motion displacement on the dynamic response of single degree of freedom system (SDOF), especially the nonlinear dynamic response, is studied under the condition that the input earthquake acceleration response spectrum and the peak velocity are constant. First, two sets of artificial ground motion time history with the same peak velocity but twice the peak displacement are synthesized by the method of superimposing narrow-band time-history in the time domain. Secondly, the stiffness characteristics of SDOF system are described by using the initial self-oscillation period of the ideal elasto-plastic SDOF system. The degree of development of the nonlinear mechanical behavior is described by the yield strength attenuation factor. By comparing the difference of the seismic responses of the two systems under the input ground motions, The effect of peak displacement of ground motion on the elasto-plastic seismic response of the system is revealed. When the nonlinear mechanical behavior of the structure is fully developed, the peak displacement of the input vibration will increase significantly under the same response spectrum and peak velocity Increase the elasto-plastic velocity and displacement response of the longer periodic structure, and this augmentation effect is more pronounced for the displacement reaction.