Aspect Ratio Dependency of Magneto-Rheological Elastomers in Dynamic Tension-Compression Loading

In this study, the effects of aspect ratio (AR) on the magneto-rheological elastomers (MREs) in tensile–compressive loading have been investigated considering magnetic field intensity, deformation rate, and amplitude in a moderately wide range. For this purpose, first, several MREs with different ARs (0.268–0.539) have been constructed. Then, using the Instron device, a test setup has been designed to identify the behavior of MREs in different magnetic fields in tensile–compressive mode. To provide the magnetic field, six permanent magnets made of neodymium 42 have been used. The MREs have been harmonically actuated with different deformation amplitudes (8%–14%) and deformation rates (1–8 Hz). The results illustrated a moderate impact of the AR on the hysteretic response of the MREs and also on its storage modulus. Results showed that the compressive and tensile storage moduli of MREs can increase up to 39.87%, and 52.70%, respectively, by decreasing the value of AR from 0.539 to 0.268. Furthermore, the MR effects of 29.95% and 21.66% for the compressive and tensile storage moduli, respectively, have been achieved. Finally, considering field intensity and mechanical deformations, an empirical mathematical model has been suggested to predict the compressive–tensile hysteretic response of MREs in the presence of AR and validated by the experimental results.