Design, performance test and analysis on magnetorheological damper for earthquake mitigation

As a semi-active control device, magnetorheological (MR) dampers have been paid more attention because of their high controllability, fast response and low power requirement. When MR dampers are used for vibration mitigation, some challenge topics must be taken into account, such as design method, performance study and intelligent control algorithm. In this paper, a detailed design process of MR damper involving the geometry design and magnetic circuit design is carried out, and a multistage shear-valve mode MR damper is designed and manufactured. Then the MR damper is tested to investigate the influence of control current, displacement amplitude and excitation frequency on the damper's mechanical behavior and energy dissipation performance. At the same time, the design target values are compared with experimental results. Comparison results show that the proposed design method holds promise in designing and optimizing the MR damper. Finally, a modified Sigmoid model is proposed. Comparison results between the experimental data and the numerical data indicate that the modified Sigmoid model can accurately describe the behaviors of the MR damper. Copyright (c) 2012 John Wiley & Sons, Ltd.