Long-wave magnetomechanical instabilities in fiber-reinforced magnetoactive composites

We investigate the long-wave magnetomechanical instabilities in magnetoactive elastomer (MAE) composites undergoing finite strains in the presence of a magnetic field. In particular, we identify the unstable domains for MAE composites with periodically distributed circular and elliptical fibers embedded in a soft matrix. We use the isotropic Langevin model for magnetic behavior, to account for the initial (linear) susceptibility and saturation magnetization of the magnetoactive fibers. We analyze the influence of the applied magnetic field and finite strains, as well as particle shape and material properties, on the stability of the MAE composites. We find that the stable and unstable domains can be significantly tuned by the applied magnetic field, depending on deformation, microstructure and magnetic properties of the fibers such as initial susceptibility and saturation magnetization.