设置椭圆形轨道负刚度装置的隔震结构抗震性能研究

文章设计了一种新型椭圆形轨道负刚度装置, 该装置由椭圆形曲面轨道、预压弹簧和滑轮组成。首先, 推导了该装置的力-位移关系表达式, 分析了预压弹簧刚度、初始预压缩量、椭圆形轨道长短半轴比值等参数对椭圆形轨道负刚度装置力-位移关系的影响; 然后, 将该负刚度装置应用到基础隔震结构中, 对分别设置椭圆形轨道负刚度装置和不设负刚度装置的基础隔震结构的频域响应特性进行分析和对比; 最后, 对实际地震动作用下5层隔震结构的地震响应进行分析。结果表明, 采用新型椭圆形曲面轨道负刚度装置, 结构各层层间位移和绝对加速度响应均有一定程度的降低, 进一步验证了该装置的有效性。

A novel elliptical negative stiffness device (ENSD) has been developed, comprising an elliptical curved track, preloaded springs and pulleys. Firstly, the force-displacement relationship of the ENSD was derived. Parametric studies were conducted to analyze the effects of preloaded spring stiffness, initial compression, and the aspect ratio of the elliptical track on the force-displacement characteristics of the ENSD. Then, the ENSD was applied to the base-isolated structure, and the frequency-domain response characteristics of the base-isolated structure with and without the ENSD were analyzed and compared, respectively. Finally, the seismic responses of a five-story base-isolated structure under actual earthquakes were analyzed. It was found that, by using the new negative stiffness device with elliptical curved track, the inter-story displacement and absolute acceleration of the structure at all stories were reduced to a certain extent, which further verified the effectiveness of the device.