We focus in this paper on a multiscale modeling approach of the materials’ reversible behavior involving couplings of the chemo-magneto-thermo-mechanical type. It is shown that it is possible to take into account a large variety of these coupled environments by a unified approach using the springs of the scale change and the build of an appropriate Gibbs free energy function. The approach is well suited to situations where some fields can be considered homogeneous at a relevant scale and where free deformation can be defined.

Magneto-rheological elastomers belong to the class of smart materials whose mechanical properties can be controlled by an external magnetic field. These materials can be integrated into mechatronic systems and submitted to multiple loadings such as temperature, mechanical stress and magnetic field. Thus, the present work is dedicated to the development of a magneto-mechanical bench and on first experimental characterizations of hard magneto-rheological elastomers taking multiphysics coupling into account. Regarding the mechanical loading, the experimental setup is able to create a uniaxial tensile stress in case of low strain (< 1%) without friction effect. In regards to the magnetic loading, a magnetic circuit made of a strong permanent magnet has been designed to impose a variable and a homogeneous magnetic field strength up to 41 kA/m. Experimental analysis has been performed on silicone rubber filled with 36%vol. of NdFeB particles. The purpose was first to investigate the evolution of the Young modulus with or without magnetic field. Results obtained from measurements show that the developed test bench is able to depict the mechanical behavior and phenomena linked to rubber-like material.

The present paper deals with the improvement of a multi-scale approach describing the magneto-mechanical coupling of Fe-27wt%Co-0.5wt%Cr alloy. The magnetostriction behavior is demonstrated as very different (low magnetostriction vs. high magnetostriction) when this material is submitted to two different final annealing conditions after cold rolling. The numerical data obtained from a multi-scale approach are in accordance with experimental data corresponding to the high magnetostriction level material. A bi-domain structure hypothesis is employed to explain the low magnetostriction behavior, in accordance with the effect of an applied tensile stress. A modification of the multiscale approach is proposed to match this result.