Experimental validation of a magnetorheological energy absorber design optimized for shock and impact loads

A linear stroke adaptive magnetorheological energy absorber (MREA) was designed, fabricated and tested for intense impact conditions with piston velocities up to 8 m s−1. The performance of the MREA was characterized using dynamic range, which is defined as the ratio of maximum on-state MREA force to the off-state MREA force. Design optimization techniques were employed in order to maximize the dynamic range at high impact velocities such that MREA maintained good control authority. Geometrical parameters of the MREA were optimized by evaluating MREA performance on the basis of a Bingham-plastic analysis incorporating minor losses (BPM analysis). Computational fluid dynamics and magnetic FE analysis were conducted to verify the performance of passive and controllable MREA force, respectively. Subsequently, high-speed drop testing (0–4.5 m s−1 at 0 A) was conducted for quantitative comparison with the numerical simulations. Refinements to the nonlinear BPM analysis were carried out to improve prediction of MREA performance.