Seismic response analysis for nonlinear base-isolated structure with TMD under near fault ground motions

The nonlinear seismic response anlysis for Base-Isolated Structure with TMD that has been proposed is carried out under near fault gound motions. The Bouc-Wen model is used to simulate the isolation layer's nonlinear force-deformation behavior, the motion equation is established. The nonlinear differential equation is solved by using the fourth-order Runge-Kutta method in Matlab. A eight-story base-isolated structure is employed herein as an numerical example, The reduce quantity of the isolation layer's peak displacement is used as evaluation index and the effect ot the pulse period of the ground motions, pre-yield stiffness of the isolation bearing and the tuning frequency on the hybrid control system's effectiveness is studied. Analysis results indicate that the pulse period has an larger effect on the control effectiveness, and when the pulse period is close to the BIS fundamental period, this control strategy is very effective; the control strategy becomes more effective when the pre-yield stiffness becomes larger; in addition, the tuning frequency of the TMD has a large effect on the control effectiveness, and it depends on the state of the isolation layer under ground motions.