Abstract
Magnetorheological (MR) dampers are one of the most promising devices for vibration mitigation, because they have large force capacity, high dynamic variety, low power requirements and mechanical simplicity. These devices have been already utilized in shear and valve mode in MR dampers. They have been investigated by engineers and researchers widely. Recently, researchers are highly interested in using MR dampers in squeeze mode, since it has a large force capacity. This force generates camper with valve and shear mode applied in MR-dampers [1]. Squeeze mode takes advantage of this fact to create a novel MR-damper. In this study, the main MR material is MRF-140CG. It is produced by Lord Corporation. Technical information provided from data-sheet of Lord Corporation. The physical proprieties of MRF-140CG material is listed in table 1[2], and The particles size of MRF-140CG was determined using a scanning electron microscope (SEM) the particles size is approximately in the range of 0.88 to 4.03 mu m. Finite element method magnetic (FEMM) software package was used to simulate magnetic circuit design and to optimize the apparatus geometry. This FEMM was used to generate the requited damping force in MR damper. Fatigue machine model (ESH 976080) was used to examine the specimen. Test environment was drive to be like a real environment on the road situation by adjusts the parameters of MR damper from sinusoidal displacement cycles with frequency of 6 Hz. This value allows MR damper to work in a range from 0.1 to 1m/s, which correspond to typical velocities of a vehicle suspension due to the road excitation [3].
In this paper, theoretical study and experiment work are carried out on a completely new MR-damper in squeeze mode, which can be used in many applications as vehicles suspension system. The MR damper technology presented in this paper has a great development in damping force and geometry, which is capable of carrying a large amount of force in squeeze mode.