A MAGNETORHEOLOGICAL DAMPER WITH BIFOLD VALVES FOR SHOCK AND VIBRATION MITIGATION

摘要

This paper presents the design and fabrication of a flow-mode bifold magnetorheological (MR) damper for shock and vibration mitigation for high piston velocity (15mph or 6.71 m/s) as well as an evaluation of its performance at low speed. Based on a Bingham-plastic model, as well as a Bingham-plastic model coupled with a low speed hysteresis model, two theoretical MR damper models for flow-mode MR dampers are constructed. Using the design strategy associated with the Bingham-model based damper model, two MR damper designs for achieving the performance requirement with a limited space are considered: first, the conventional MR damper that has an MR valve inside the piston head and second, the bifold MR damper that has MR valves at each end of the damper. After numerically comparing the damping performances of two MR damper designs, the bifold MR damper was chosen because its dynamic range was better at high speed. The bifold MR damper was tested at relatively low piston velocity using an MTS testing machine under sinusoidal loading. Experimental data are compared well with the results predicted by the theoretical models.