Modeling and Multi-field Simulation of a Self-Protecting Squeeze-Shear Magnetorheological Brake

Traditional magnetorheological (MR) brakes are widely applied in high-precision systems but face challenges such as insufficient torque and strict safety requirements. These brakes are unable to maintain their braking state after an emergency shutdown, limiting their use in high-safety environments. This study aims to improve both braking torque and safety by designing a multi-disc MR brake incorporating a self-protection mechanism and a wavy disc surface, which operates in a combined squeeze-shear mode. A mathematical model for braking torque was developed using the Bingham model and slab method. Finite element simulations were conducted to analyze the electromagnetic and thermal fields of the designed brake. The relationship between braking torque and current was also established through advanced optimization techniques. Simulation results demonstrate that the braking torque reaches a peak of 182.7 Nm under a current of 4A. During continuous braking at 4A for 40 s, the temperatures of all components remained within permissible limits.