Effectiveness of Semi-Active Variable Stiffness Tuned Mass Damper for Seismic Load Using LQR Control

Jain Aadarsh; Dr. S. N. Deshmukh

doi:10.3759/rtcet.v10i1.3627

Abstract

In this study, effectiveness of semi-active variable stiffness tuned mass damper in reducing seismic response of 10-story frame structure is evaluated. The variable stiffness device, comprising four spring, having rhombus configuration, adapted from literature is attached to the tuned mass damper. A control algorithm using state space form of governing equation of motion is developed. LQR controller is employed to obtain control force based on displacement and velocity response feedback. The necessary control force is achieved by varying the stiffness of semi-active variable stiffness around the nominal stiffness of device. The Semi active variable stiffness tuned mass damper with LQR control (SVTLC) is designed for El-centro earthquake and its effectiveness is evaluated for el-centro earthquakes and other three earthquakes. The responses of controlled structure with SVTLC are compared with that of uncontrolled structure and structure with passive TMD (PTMD). The displacement and acceleration responses suggest that a better control is achieved by SVTLC over PTMD. Performance evaluation criteria shows the SVTLC effectively reduces the seismic response of structure as compared to PTMD at the cost of small external power supply.