TMD-基础隔震混合控制体系在近场地震作用下的能量响应与减震效果分析

Energy response and anti-vibration effect analysis for a base-isolated structure with TMD under near-field earthquake

基于能量平衡原理对近场地震作用下TMD-基础隔震混合控制体系进行了能量响应分析,研究了不同脉冲周期地震作用下混合控制体系的减震效果。采用Bouc-Wen模型模拟隔震层的非线性力-变形行为,建立了TMD-基础隔震混合控制体系的运动方程和相对能量平衡方程。以某八层基础隔震结构为算例,运用四阶龙格-库塔法和梯形法分别对结构安装TMD前后的非线性地震响应和能量响应进行求解,分析了混合控制体系中输入能量的变化和耗散过程。分析结果表明:以隔震层峰值位移作为控制对象时,TMD的控制效果并不好;从能量的角度来看,TMD对主结构的输入能,特别是隔震层滞回耗能的控制非常有效,这是因为TMD的阻尼耗散了体系中的大部分输入能;不同脉冲周期地震作用下TMD的减震效果差别较大,对TMD最优参数进行求解时应考虑地震动特性的影响。

Based on the energy balance principle,the energy response anlysis of a hybrid control system consisted of base-isolation and TMD was performed,and the vibration control effectiveness of the hybrid control system under seismic ground motions with different pulse periods was studied.Bouc-Wen model was adopted to simulate the isolation layer＇s nonlinear force-deformation behavior.The motion equation and the relative energy balance equation of the system were established.A eight-storey base-isolated structure was employed herein as an numerical example.The seismic response and energy response of the base-isolated structure with and without TMD were calculated using the fourth-order Runge-Kutta method and the trapezoidal rule,respectively.The input energy＇s variation and dissipation process of the hybrid control system were analyzed.The analysis results showed that TMD＇s control effect on the isolation layer＇s peak displacement is not good;from the standpoint of the energy,TMD＇s control over the input energy of the primary structure, especialy,over the isolation layer＇s hysteretic energy is very effective due to the energy dissipation using TMD＇s damping;there are different control effectivenesses of TMD under seismic ground motions with different pulse periods,and the influence of the seismic ground motion＇s characteristics should be considered when solving TMD＇s optimal prameters.