広いダイナミックレンジを有するせん断型MR グリースダンパによるセミアクティブ制振

抄録

This paper describes the performance of semi-active vibration suppression by a shear-type MR grease damper with the high dynamic range. The shear-type damper using magnetorheological grease (shear-type MR grease damper) is controllable; the damping force is controlled by the electric current since the rheological properties of MR grease is substantially changed by an external magnetic field produced by the built-in electromagnet. The shear-type MR grease damper was developed to overcome the two issues in conventional pressure-type MR fluid dampers: the low dispersion stability and the low dynamic range. By applying MR grease with high dispersion stability, the damping performance could be maintained for a longer time. Furthermore, the higher dynamic range could be achieved by applying the semisolid MR grease to the shear-type damper not requiring sealing elements. In this study, in order to verify the advantage of the high dynamic range of the shear-type MR grease damper, the vibration suppression test using a small model structure is conducted. A skyhook-based control law is used as an algorithm for semi-active vibration suppression. The effect of the dynamic range on the vibration suppression performance is investigated by comparing the performance under conditions of high dynamic range and lower dynamic ranges. The experimental results demonstrate that the higher dynamic range results in higher suppression performance over a wide frequency range. Therefore, it is indicated that the shear-type MR grease damper with the high dispersion stability and the high dynamic range can exhibit high performance in semi-active vibration suppression of single-degree-of-freedom systems.