An Improved Model of Magnetorheological Elastomer of Frequency, Magnetic Field, and Amplitude Responses

Magnetorheological elastomers (MRE) are smart materials that have recently attracted considerable interest. The mechanical properties of MREs change significantly in the presence of a magnetic field. This study investigates the MRE properties and proposes a new model for designing systems using MRE. First, an MRE material fabrication process is introduced, and the dynamic properties of the MRE are investigated under different magnetic field strengths, frequencies, and amplitudes. The smooth Coulomb friction model is well known, representing the amplitude-dependent mechanical properties well. However, the model was inefficient when describing materials' properties at the low strain frequency (< 2 Hz). In this study, an improved Coulomb friction model has been developed to improve this problem by adding the strain velocity influence factor. Furthermore, the fractional viscous and variable stiffness models represent the material properties dependent on the frequency and magnetic field. Finally, a simple procedure, with easy computation, is proposed for determining the model parameters. The model results are compared with two classical models, the Coulomb model and the Bouc-Wen model. The developed model overcomes the disadvantages of the smooth Coulomb friction model when applied at low frequencies. Simulation and experimental results show that the proposed model achieves a deviation of just under 6 % in most cases, lower than when implementing the classical Coulomb friction (8 %) and hysteresis Bouc-wen models (7 %). The model also achieved similar accuracy when used for laminated MRE.