Precise stiffness and damping emulation with MR dampers and its application to semi-active tuned mass dampers of Wolgograd Bridge

This paper investigates precise stiffness and damping emulation with MR dampers when clipping and a residual MR damper force constrain the desired control force. It is shown that these force constraints lead to smaller equivalent stiffness and greater equivalent damping of the constrained MR damper force than desired. Compensation methods for precise stiffness and damping emulations are derived for harmonic excitation of the MR damper. The numerical validation of both compensation methods confirms their efficacy. The precise stiffness emulation approach is experimentally validated with the MR damper based semi-active tuned mass damper (MR-STMD) concept of the Wolgograd Bridge . The experimental results reveal that the precise stiffness emulation approach enhances the efficiency of the MR-STMD significantly when the MR-STMD is operated at reduced desired damping, where the impact of control force constraints becomes significant.