Dynamic Model And Experimental Study Of Magnetorheological Dynamometer

Magneto-rheological fluid(MRF) is a new type of intelligent material, which can occur MR effect under the influence of an external magnetic field, instantly change their rheological properties, the viscosity can be increased several orders of magnitude. Due to the continuous, reversible and rapid response characteristics, MRF has become one of the hottest smart materials research, scholars from various countries invest a lot of manpower,material and financial resources for the development of MRF materials and transmission devices.In this dissertation, in view of the development and research status of MRF and transmission devices, and combined the research of this subject, the MRF dynamometer test bench has been built, the characteristics of MRF has been systematically studied, the MRF dynamometer dynamics model has been analyzed and established, the dynamic tests of MRF dynamometer have been designed and completed, the transmission performance of MRF dynamometer has been analyzed. The research of this paper lay a foundation for the application of MRF in the engineering field.The specific contents are as follows:1) MRF and MR effect are described, the composition and preparation methods of MRF are introduced, the performance parameters of MRF and its influencing factors are systematically analyzed, the extensive application of MRF in transmission field and some major projects are cited.2) The basic structure and working mode of MRF dynamometer is introduced.The working principle of MRF dynamometer is explained, the characteristics, requirements and failure modes of MRF dynamometer transmission are analyzed. Based on Binghamfluid model and Navier-Stokes equations, the torque transmission model of MRF dynamometer and the flow model of MRF are analyzed and established. The above models are simulated by applying mathematical tool.3) The MRF dynamometer test bench is introduced, the operation mode and process of testing system are described in detail. Based on the theoretical analysis, the dynamic tests associated with MRF dynamometer are designed and experienced, the various characteristics of the dynamometer transmission such as no-loaded torque, viscous torque, static characteristics and speed characteristics are tested, the deviation between theoretical analysis and experimental results is comparative analyzed.4) The transmission performance of MRF dynamometer and its influencing factors are researched and analyzed, the available methods of increase the transmission torque and reduce the power loss are discussed, the control coefficient and response time is defined, the response time of field coil circuit and the rheological time of MRF and their respective factors are analyzed.