串联隔震构件恢复力计算模型试验研究

Research on hysteretic restoring force model of series isolation components

为研究串联隔震构件使用阶段的真实力学性能,基于5组不同轴压比、长细比的串联隔震构件进行拟静力加载试验,并建立构件的有限元模型,对受力特点及破坏状态进行分析。根据对应工况下的有限元模型获得滞回曲线,建立了串联隔震构件的三折线型骨架曲线,同时给出了骨架曲线各分段的方程表达式。针对试验过程中变幅循环加载引起的构件整体刚度发生退化的问题,将各组构件的滞回曲线划分为4个部分,以每组构件的初始加载刚度为基准,采用非线性回归分析方法,获取每段曲线刚度退化规律,结合骨架曲线,建立了串联隔震构件的恢复力模型,并与试验进行对比。结果表明:提出的恢复力模型可以较为准确地描述串联隔震构件在低周往复荷载作用下的恢复力特性,为后续非线性力学性能研究提供理论参考。

In order to study the real mechanical properties of the series isolation components in service stage,this research not only carried out the pseudo-static loading test on five groups of series isolation components with different axial compression ratios and slenderness ratios,but also established the finite element model of the components for analyzing the mechanical characteristics and failure state.According to the hysteretic curve which was obtained from the finite element model under the corresponding working conditions,the trilinear skeleton curve of series isolation components was established.Meanwhile,the equations of each segment of skeleton curve were given.As for the degradation of the integral stiffness of the component caused by cyclic loading of variable amplitude during the test,this study divided the hysteretic curves of each component into four parts;and then,based on the initial loading stiffness of each component group,the nonlinear regression analysis method was adopted to obtain the stiffness degradation rule of each curve;finally,combined with the skeleton curve,the restoring force model of series isolation component was established.Compared with the test,the results show that the proposed restoring force model can accurately describe the restoring force characteristics of series isolation components under low cyclic reciprocating load,which provides theoretical reference for the follow-up study of nonlinear mechanical properties.