位移相关摩擦阻尼器基础隔震结构地震响应分析

摘要

考虑了阻尼器中斜坡面反力对位移相关摩擦阻尼器输出力的贡献，从而完善了阻尼器的力学模型，并以一个典型的5层剪切型结构为例，评估了位移相关摩擦阻尼器对橡胶基础隔震结构抗震性能的影响。数值分析表明，位移相关摩擦阻尼器能减小常规地震作用下隔震层的位移响应，但是会增加隔震结构的底层剪力和顶层加速度；在近断层脉冲型地震波作用下，阻尼器能够显著降低隔震层位移，同时对上部结构的地震响应也有较好的抑制作用。此外，位移相关摩擦阻尼器的弹簧初始位移、弹簧刚度和楔块坡面角度这三个参数对隔震结构抗震性能的影响也进行了分析。%The mechanical model of a displacement dependent friction damper was improved by considering the contribution of slope reaction to output force generated by the damper.Then,taking a five-storey base isolated structure as an example,the influence of the damper on seismic-resistant behaviors of the base isolated structure with lead rubber bearings was evaluated.The numerical analysis shows that the friction damper can effectively reduce the displacement of isolation floor while increase the base shear force and the top floor acceleration of the main structure under normal seismic excitation.When the building is subjected to the near-fault pulse-type earthquake,the displacement of isolation floor is significantly reduced and to some extend the seismic response of the main structure is also suppressed.In addition,three main parameters determining the mechanical property of the displacement depended friction damper,that is,initial displacement,stiffness of spring and slope angle,are of obvious influences on the seismic response of isolated structures, which were investigated detailedly.