DYNAMIC BEHAVIOUR OF SHEAR-TYPE MAGNETORHEOLOGIC GREASE DAMPER ROTOR SYSTEM

Abstract

In order to greatly reduce the effect of sedimentation in magnetorheological fluids (MRF) on dynamic behavior of the MRF based devices, a kind of magnetorheological greases (MRG), whose Theological property can also be significantly changed on the application of an external magnetic field, is presented, and a MRG based shear-type damper operating in shear mode for rotor system of rotational machinery and a flexible rotor system with an over-hung disk are developed. The controllability of the shear-type MRG damper on the dynamic behavior of a rotor system, the effectiveness of the shear-type MRG damper for attenuating the rotor's vibration, the suitability of the MRG damper for active vibration control of rotor systems, and the repeatability of the dynamic characteristics of the shear-type MRG damper rotor system during a longer period of time are experimentally studied in the flexible rotor system. Results show that the dynamic behavior of the shear-type MRG damper rotor system can be controlled on the application of an external magnetic field produced by a low voltage electromagnetic coil, the shear-type MRG damper can greatly suppress the vibration of the rotor system at a properly magnetic field, the dynamic behavior of the shear-type MRG damper rotor system does not change during a longer period of time, and the shear-type MRG damper is suitable for an actuator to actively control the vibration of rotor systems.