Numerical investigation on the magnetostrictive effect of magneto-sensitive elastomers based on a magneto-structural coupling algorithm

Magneto-sensitive elastomers (MSEs) are composite materials with ferromagnetic particles embedded in rubber matrices. Their mechanical properties can be changed by applying an external magnetic field. Although their stiffness and damper properties have been extensively studied, only a few studies have been involved with their magnetostriction behaviors, which have potential applications in sensors. To observe the interaction mechanisms between mechanical and magnetic fields and to investigate the magnetostrictive effect numerically, a novel magneto-structural coupling algorithm was developed. A magnetostrictive test system was also developed and fabricated for validating the simulation method. Several MSE samples embedded with millimeter-sized particles were fabricated and tested. The simulation results agreed well with the experimental results. Also both of them showed negative magnetostrictive strains for the specified samples and test conditions in this study. The contributions of four influencing factors were evaluated, and some results were concluded. Before magnetic saturation, the bigger the magnetic field strength is, the stronger the magnetostrictive effect is, and their relationship follows a quadratic polynomial expression. The closer the distance between two adjacent particles is, the stronger the magnetostrictive effect is, and their relationship satisfies a cubic polynomial equation. The higher the particle volume fraction is, the stronger the magnetostrictive effect is, and there is a linear relationship between them. The particle diameter has little influence on the magnetostrictive effect. (paper)