Characteristic analysis under small-stroke and medium-high frequency of magneto-rheological damper with pressure controlled mechanism

Abstract

AbstractDue to the high frequency hardening effect in applications of satellite and precision vibration isolation, it is an urgent need to analyze and improve the magnetorheological (MR) performance of MR damper under small-stroke and medium-high frequency excitations. In this paper, a compact MR damper with pressure controlled mechanism is proposed, analyzed and tested. Considering the inertial, pre-compression and compressibility of MR fluid, the dynamic physic model is established to analyze the output characteristics with pre-compressions under small-stroke and medium-high frequency excitations. And then, the critical model between the pre-yield region and post-yield region is obtained. The critical boundary between different excitations is derived and comparatively analyzed. Finally, the experiments with the proposed MR damper are carried out. Compared with theoretical results, the damping force and dynamic stiffness increase with the increase of the applied current and excitations. Besides these, the energy dissipated performance can be improved by the pre-compression. When the initial pressure increases to 5 MPa with the fixed frequency of 10 Hz, the energy dissipation is increased by 43.5%. So the pre-compression is an effective way to solve the high frequency hardening. Besides these, the derived critical model can predict the performance of MR damper at different excitations.