Dynamic Characterization and Modeling of Isotropic Magnetorheological Elastomers Under Tensile-Compressive Loadings

This paper presents dynamic behavior of an isotropic magnetorheological elastomer (MRE) under harmonic tensile-compressive loadings. The dynamic viscoelastic behavior of the MRE is experimentally investigated at various external magnetic fields as well as different loadings of frequency and strain. A generalized Maxwell viscoelastic model is developed to portray the relationships between the stress and strain of the MRE based on input frequency, strain, and magnetic flux density. The coefficients of the proposed model under various input conditions, such as magnetic flux density, strain amplitude, and input frequency, are calculated by implementing the least-squares method. Unlike the previous models of MRE, which mostly focused on shear mode, the present model enables to capture dynamic behavior of MRE in tensile-compressive loadings. Furthermore, tensile-compressive operation offers the most compact design in many axial loading applications such as rotor systems, MRE bearing isolators in bridges, suspension systems in cars, building isolators, and vertical vibration settings, which cannot be controlled with MRE in shear mode due to its low capacity of stiffness. The results show that the proposed model can effectively predict dynamic behavior of MREs under tensile-compressive loadings. This model is useful to simulate the performances of MRE base devices under harmonic tensile-compressive loadings.