Comparative Study on Axial Magnetorheological Effect and Shear Magnetorheological Effect of Magnetorheological Elastomer

Abstract

The magnetorheological effect of magnetorheological elastomer (MRE) suggests that the viscoelasticity of MRE can be reversibly regulated by magnetic fields in real time. Presently,MRE intelligent variable stiffness isolation device mainly employs the magnetorheological effect of materials in the shear direction, in which case the research on MRE magnetorheological effect is largely focused on the shear direction. However,in the vertical isolation,such study mainly deals with the axial magnetorheological effect of MRE. Our paper,which studies the magnetorheological effect of MRE under axial load through experiments, tries to draw a comparative analysis between the magnetorheological effect with that under shear load. Based on the electronic universal testing machine and excitation device,the axial magnetorheological effect test system was designed,and the shear magnetorheological effect was studied by rotating rheometer. Under the two operating modes,the magnetic field intensity was adjusted between 0~184kA/m, whereas the strain amplitude range varied from 5% to 15%. The tension-compressive hysteretic curves and shear hysteretic curves of MRE under different magnetic fields were obtained,and the viscoelastic mechanical parameters under different working conditions were calculated. The test results show that MRE has good characteristics of magnetostrictive variable modulus and variable damping under axial load. Compared with shear mode,the storage modulus and loss modulus under tension-compressive mode are improved, while the damping loss factor is relatively smaller.