Heating of Long-Stroke Magnetorheological Fluid Damper

Magnetorhelogical (MR) dampers are gradually used in military devices for shock isolation and civil structures for suppressing earthquake-induced shaking and wind-induced vibrations because of their mechanical simplicity, high dynamic range, low power requirements, large force capacity and robustness. Since MR fluid dampers are energy-dissipating device, the issues of heat generation and dissipation is important. In this study, phenomenon of viscous heating and consequent temperature increase in a long-stroke MR damper are presented. In addition, a theoretical model is developed which predicts the temperature increase in the long-stroke MR damper. This model is solved numerically and a new coupling method was proposed to analyze the electromagnetic-thermal coupling problem on the basis of the mechanism of coupled field. Aim at the high frequency of piston head moving back and forth, as well as the changing current, the simulation model is established. The results show that the temperature effect on the damping force is significant and provide a theoretical basis and calculation method for the design and analysis of long-stroke MR damper.