Stiffness and Damping in Fe, Co, and Ni Nanowire-Based Magnetorheological Elastomeric Composites

The stiffness and damping properties of the aligned magnetorheological (MR) elastomer composites filled with 10 wt% Fe, Co, and Ni nanowires were investigated under normalized strain amplitude of 1, 2, and 3%, cyclic deformation frequency of 1 Hz, and magnetic flux density of 0, 0.1, and 0.2 T. The highest values of the dynamic stiffness are observed for the Ni- and the lowest for the Fe-based composites within the whole range of strain amplitude and magnetic flux density. The MR effect on the dynamic stiffness is the most significant for 1% strain amplitude and it almost completely disappears for 3% amplitude for all composites. The equivalent damping coefficient values have maxima for 1% strain amplitude for all composites. These values abruptly drop with an increase of strain amplitude to 2% and only slightly change as strain amplitude is further increased to 3%. The MR effect on the equivalent damping coefficient is high for all composites and strain amplitudes.