| The magnetorheological(MR) fluid is a kind of smart materials, which has special rheological property. With the action of magnetic field, the states can be changed from fluid to semisolid, and the process above is reversible. Since the shear yield strength of MRF can be controlled by adjusting the magnetic field intensity, there has great advantages in semi-active vibration control field by using the magnetorheological damper(MRD), which is based on the MR technology. For example, in order to meet people’s requirements for the vehicle riding comfort and stability, in the vehicle suspension system,the most frequently used damping device is the MR dampers.Because of the coupling interaction among the MR fluid, the structural components and the electromagnetic field, the dynamic characteristics of MRD has a strong nonlinear relation. Therefore, to get a good control performance, multi-field coupling mechanism should be analyzed in depth to obtain a more accurate dynamic model. In this paper, dynamic response and its influencing factors of the magnetorheological damper are investigated by doing the mechanical modeling, the multi-field coupling simulation, and the dynamic response analysis, which aim at providing the theory basis for the design of the magnetorheological absorber used in the piping semi-active vibration control. This paper mainly includes the work as follows:(1) Analysis of the estimation ability of the magnetorheological damper mechanical model. Building the pseudo-static model and the dynamic model, and identificating the parameters of the model, so that to obtain the estimation ability of the annular channel model, the Bingham model and the Bingham-polynomial model which can be used to evaluate the dynamic characteristics of MRD.(2) Multi-field Coupling Simulation for magnetorheological damper. Taking the ADINA finite element software as the simulation platform, the simulation model of the multi-field coupling including the structure field, the flow field and the electromagnetic field can be built and analyzed to obtain the damping properties of MRD, so that to lay the foundation on studying the dynamic characteristics of MRD.(3) Analysis of the dynamic response of the magnetorheological damper. The dynamic response model of MRD is established, and the effect of parameters of the MR fluids and the electromagnetic circuit on the dynamic response is analyzed. Response time of the electromagnetic circuit is calculated by analyzing the magnetic-field distribution inside the MRD. In order to analyze the influencing factors of response time lag in electromagnetic circuit, the computing model of eddy-current loss and hysteresis loss have been built. This chapter provides a theoretical basis for the magnetic circuit design.(4) Experimental research on dynamical characteristics of the magnetorheological damper. To obtain the dynamic characteristic curve of the magnetorheological damper, an experiment is completed with the help of dSPACE simulation platform, and the experimental data is filtered by using the Butterworth filter. Moreover, the test results are used to be compared with the curves of pseudo-static model and multi-field coupling model, so that to verify the accuracy of the quasi-static model and the simulation model. |
