Abstract
This paper describes a successful application of Magnetorheological (MR) grease to a shear type controllable damper. MR fluid is known as a kind of functional fluids which changes rheological property when an external magnetic field is applied. However, there is a problem with the sedimentation of the dispersed particles. To prevent the sedimentation, MR grease was developed. In this study, we developed a shear type controllable damper using MR grease. The performance test demonstrated that the proposed damper has wide dynamic range of damping force despite its simple structure. The ratio of maximum damping force in on-state to that in off-state is approximately 65. In addition, the proposed damper was installed between first floor and second floor of a one-story model structure. The vibration control test demonstrated that the vibration response was successfully reduced by using the simplified skyhook algorithm. Our results indicate that the MR grease damper effectively works for the semi-active vibration control system.
