Shock attenuation mechanisms of magnetorheological elastomers absorbers: A theoretical analysis

To predict the dynamic response of shock absorbers based on magnetorheological elastomers and investigate the contributions of various possible energy dissipation mechanisms, a modified four-parameter model of magnetorheological elastomers was proposed, which includes the viscoelastic characteristics of rubber matrix, the variable stiffness and damping property, and the interfacial bond conditions of magnetorheological elastomers under the applied magnetic field. The constitutive equations of magnetorheological elastomers were derived and all parameters were identified based on a published literature. It is theoretically demonstrated that the maximum response force under an impulse input could be attenuated approximately 30% when the magnetic field with 0.57 T is applied. Using the proposed theoretical model, it is shown that the energy dissipation mechanisms mainly come from the interfacial friction between particles and matrix, and the increment on stiffness and dynamic viscosity of the rubber matrix provides reverse contributions to the shock mitigation, while the interfacial bond stiffness has little influence on the response force amplitude. Hence, when magnetorheological elastomers are utilized in shock absorbers, it is suggested to take advantage of the interfacial friction energy.