To cite this version:Dipayan Mukherjee, Laurence Bodelot, Kostas Danas. Microstructurally-guided explicit continuum models for isotropic magnetorheological elastomers with iron particles.
AbstractThis work provides a family of explicit phenomenological models both in the F − H and F − B variable space. These models are derived directly from an analytical implicit homogenization model for isotropic magnetorheological elastomers (MREs), which, in turn, is assessed via full-field numerical simulations. The proposed phenomenological models are constructed so that they recover the same purely mechanical, initial and saturation magnetization and initial magnetostriction response of the analytical homogenization model for all sets of material parameters, such as the particle volume fraction and the material properties of the constituents (e.g., the matrix shear modulus, the magnetic susceptibility and magnetization saturation of the particles). The functional form of the proposed phenomenological models is based on simple energy functions with small number of calibration parameters thus allowing for the description of magnetoelastic solids more generally such as anisotropic (with particle-chains) ones, polymers comprising ferrofluid particles or particle clusters. This, in turn, makes them suitable to probe a large set of experimental or numerical results. The models of the present study show that in isotropic MREs, the entire magnetization response is insensitive to the shear modulus of the matrix material even when the latter ranges between 0.003-0.3MPa, while the magnetostriction response is extremely sensitive to the mechanical properties of the matrix material.two-dimensional MREs. Moreover, in an effort to resolve some of the surrounding air and specimen effects, Kalina et al. (2016) have modeled directly the specimen, the surrounding air and the microstructure at the same scale. While this study has led to satisfactory qualitative agreement with experiments, it did not resolve the different length scales as one goes from specimen to microstructure, since that would require an untractable mesh size. Along this effort, Keip and Rambausek (2015) proposed a two-scale finite element approach in order to solve simultaneously the magneto-mechanical boundary value problem and the microstructural problem by properly resolving the separation of the very different length scales. While this last approach is the more complete one, it still remains numerically demanding, especially if complex unit cells with large number of particles are considered. Moreover, in all these approaches, it is very hard to decouple from the estimated response the relative effect of the specimen geometry and that of the microstructure.In this regard, the recent study of Lefèvre et al. (2017) proposes an alternative view to the problem by first solving the homogenization problem at the RVE scale analytically and then using these estimates at the macroscopic scale to analyze the specimen shape effects. In that effort, the authors obtained a very usef...