Application of soft MREs for magnetically induced actuation with implementation in FEniCSx

Abstract

In this contribution a model for a soft magnetic magnetorheological elastomer material is derived and numerically applied for magnetically induced actuation of a polymeric cantilever beam. The model encompasses both microstructural details and macroscopic behaviour of MREs through continuum mechanics framework, including nonlinear visco-elasticity and full magneto- mechanical coupling, accounting for complex material phenomena such as magnetostriction. The governing equations are derived following standard thermodynamically consistent procedure, by applying the virtual power principle for an isothermal case, arriving at the suitable free energy ex- pressions and the corresponding constitutive relations for magneto-active materials. The model is validated against the results from the literature, and then applied to analyse actuation of a polymeric cantilever beam by introducing soft-MRE patches and varying the surrounding magnetic field. The results show that soft-MREs are highly suitable for magnetic actuation and soft-robotic applications.