Analysis of a magnetorheological damper incorporating temperature dependence

Abstract

Aside from external environmental heating, a magnetorheological (MR) damper may internally self-heat due to both resistive heating by the electromagnetic coil and to a greater extent, by dissipating mechanical energy into thermal energy. Temperature can significantly alter damper behaviour, as the fluid viscosity and accumulator gas pressure are highly dependent on temperature. Therefore, to improve the understanding of the behaviour of a linear stroke MR damper, a damper designed for a ground vehicle seat suspension, its performance is characterised over temperatures ranging from 0 to 100°C. A hydro-mechanical analysis is used to represent MR damper behaviour when it is subjected to large temperature perturbations and captures contributions from fluid viscosity, fluid inertia and pneumatic compressibility. The effect of damper self-heating on the identified model parameters is presented and the connection of these parameters to physical properties is also discussed.