The elastic and damping properties of magnetorheological elastomers

The aim of this study was to increase knowledge of the mechanical and viscoelastic properties of isotropic and aligned MREs.The focus was to clarify the changes in the elastic and vibration damping properties of the MREs when they are subjected to a magnetic field and to study the influence of the alignment of the magnetic particles on the composite properties with and without an applied magnetic field.The stiffness and damping properties of MREs can be modified by applying an external magnetic field.In isotropic MREs the stiffness and damping increase in the magnetic field when the filler volume fraction exceeds 15 vol.-% and maximal damping is obtained with 27 vol.-% of filler.The damping and stiffness properties of aligned MREs depend on the mutual directions of load, magnetic field and the particle alignment in the composite.If the dynamic loading is applied in the direction of the particle chains, the damping is initially high and the applied magnetic field has only a small influence on damping but it increases dynamic stiffness.If the deformation is concentrated in the areas between the particle chains, the damping is initially lower and is increased in the magnetic field.In this case, the dynamic stiffness is quite low and the applied magnetic field does not increase it significantly