Semi-active control of seismically excited building using magneto-rheological fluid damper

Abstract

A recently developed semi-active control strategy using magneto-rheological fluid dampers is presented for vibration control of seismically excited buildings. As a control device, magneto-rheological (MR) dampers are employed because they have attractive characteristics for applications. At first, experimental studies were performed on a small size MR damper to investigate the general mechanical properties of MR damper. Numerical simulation studies are performed to demonstrate the efficacy of the semi-actively controlled MR fluid dampers on the third ASCE benchmark problem. MR fluid dampers are assumed to be installed on the lower part of the structure. Genetic algorithm is used to determine the optimal locations and capacities of the MR fluid dampers. Clipped optimal controller is designed to control the input voltage to the MR fluid dampers. The interstory drift and acceleration data are used for the feedback control. To verify the robustness with respect to the variation of the external earthquake force, several cases with different earthquake forces are considered in the numerical simulation. The results show that the peak drift ratios and absolute accelerations are reduced by 15-20% and 15-34%, respectively. The normed values are reduced by 35-45%. However the base shear is not reduced well.