A coupled magneto-mechanical-thermal constitutive model for transversely isotropic magnetorheological elastomers verified by experimental validation.

Magnetorheological elastomers, as a class of smart functional materials, have attracted considerable attention in various engineering and biomedical applications. Transversely isotropic MREs containing chain-like magnetic particle structures particularly exhibit enhanced mechanical and actuation properties compared with their isotropic counterparts. Employing nonlinear continuum mechanics framework together with finite strain theory, this study develops a physics-based constitutive model to predict the coupled magneto-mechanical-thermal behavior of such materials. In this formulation, the deformation gradient, magnetic induction, temperature, and particle-chain orientation are treated as independent variables in defining the total Helmholtz free energy function. In addition to the proposed theoretical framework, a series of experimental tests are performed for model validation and parameter identification. The overall behavior of transversely isotropic MREs is subsequently examined under different particle-chain orientations and loading conditions. For the cylindrical MRE specimen, the results show that the material stiffness increases with both magnetic field strength and temperature, and exhibits a peak response at a particle-chain tilt angle of approximately 45° relative to the axial direction.