| The research on coupling magneto-mechanical issue based on magneto-thixotropic gel (MTG) is a complex work combining electromagnetic rheological working medium with mechanical structure. The magneto-thixotropic gel is a new type of magnetic func-tion material with rheology behavior. However, compared with magneto-rheological fluid (MRF), the magneto-thixotropic gel is not able to flow and only when the magnet-ic field is present the strong mechanical properties shown to resist deformation. Mean-while, the magneto-thixotropic gel also chatacterises with better rheology, physical and chemical stability, low power, leak tightness, noiseless, easy to control and adjust. Con-sequently, the magneto-thixotropic gel could be used as a new type of working medium to substitute for MRF, its correlative devices combined electromagnetic with mechanics can be wildly used in such industrial fields as aerospace, automotive, automation, med-ical instruments and so on.By analyzing on previous related research results home and abroad, comprehen-sively considering working reliability, physical and chemical stability, magne-to-mechanical properties, the magneto-thixotropic gel is prepared by chemical reaction method in the dissertation. The theoretical investigation and analysis of characterization experiments were carried out to account for mechanism that chemical polar group in the fiber network structure to enwrap magnetic particles. Meanwhile, when the magnetic field is present, the characteristics such as current-torque characteristic, the shear rate-yield shear stress characteristic and shear rate-viscosity were tested by modified testing equipments.Based on the MTG's good magnetization property, a coupling magneto-mechanical structure of wedge squeeze damping beneficiated model was proposed, which broke through the traditional working model such as valve model, shear model, squeeze model. Associated with fluid mechanics, the stress and movement behavior of the magnetic particles under the magnetic field were analyzed. Meanwhile, the static dynamic mod-eling, theory analysis and experimental simulation were carried out to the model con-sisting of circular distributed plate working mode and the cone ring working model.The theoretical analysis of power output, creative structure design, optimization design based on the wedge squeeze model was carried out and theoretical calculation on MTG devices was fulfilled aimed to coil magnetic field distribution in the space. Meanwhile, a detail introduction to magneo-thixotropic clutchs, magneo-thixotropic brakes, magneo-thixotropic absorbers were present. At last, a high performance mag-neo-thixotropic brake prototype was manufactured.Take the high performance magneto-thixotropic brake as example, theoretical analysis and numerical simulation on rheology under electromagnetic and flow field were implemented. The magnetic circuit optimization design and electromagnetic si-mulation on magneto-thixotropic brake were done by applied ANSYS electromagnetic module. Meanwhile, aim to calculate the pressure field, velocity field, power perfor-mance of the MTG under the magnetic fields, the theoretical analysis and numerical simulation were carried out by adopting ANSYS Fluent finite volume method.In order to test beneficiated damping efficiency associating MTG with its wedge squeeze working model, a magneto-mechanical coupling performance testing test bench was built, which was used to test magnetic field-torque characteristic, working stability, magnetic hysteresis characteristic, thermal stability, slip power of the magne-to-thixotropic brake. All these experimental tests and application experiments educed some reference value of conclusion which laid a solid theoretical foundation and expe-rimental basis for further study on magneto-thixotropic deveces.Finally, the author summarized the main contribution and creative points in this paper, and had a prospect on the future research on magneto-mechanical coupling issues based on the magneto-thixotropic materials.
|
PDF Full Text Request