Phenomenological model of large-scale MR damper systems

Abstract

Magnetorheological (MR) fluid dampers provide a level of technology that has enabled effective semi-active control in a number of real world applications. This chapter provides fundamental insight into the dynamic behavior of a 20-ton MR damper capable of providing semi-active damping for full-scale civil engineering applications. A phenomenological model based on the Bouc–Wen hysteresis model is developed to describe the dynamic behavior of the large-scale MR damper. The model considers the MR fluid stiction phenomenon, as well as shear thinning and inertial effects. The use of a pulse-width modulated current driver can dramatically reduce the MR damper response time. The chapter finally discusses the operational principle of the current driver and presents its dynamic model. This dynamic model is then combined with the phenomenological model proposed for the MR damper to obtain the dynamic model of the overall MR damper system. The predicted results compare well with the experimental data, and effective predictions are obtained. This model provides a new tool for analysis and synthesis of structures employing such large-scale MR dampers.