Experimental Study On Vibration Transfer Characteristics Of Magnetorheological Fluid

Magnetorheological fluid(MRF)is a kind of controllable intelligent rheological material,which has special physical and chemical properties under the action of magnetic field.By controlling the external electromagnetic field,the damping and elastic modulus of magnetorheological material can be changed,and then change the resistance of the material to realize the vibration transmission characteristics of the magnetorheological fluid.Generally speaking,the vibration control structure does not have large structural variability and parameter adjustability,so it is not convenient to study the vibration transfer characteristics of one or more types of vibration control structures.In this paper,an experimental platform with impedance modulation is constructed with the help of the special physical and chemical properties of magnetorheological fluid.Based on this platform,we can carry on the experiment of the vibration period of the impedance period and the quasi periodic mode,which provides the basic conditions for the development of the research on the vibration characteristics of the magnetorheological material.In this paper,the following aspects of work:(1)Preparation and performance test of magnetorheological fluid.First of all,magnetorheological fluid samples with different densities were prepared according to the synthesis and preparation methods of magnetorheological fluid.Secondly,by means of the characterization and performance testing methods of magnetorheological fluid,the magnetic yield stress,zero field viscosity,storage modulus and loss modulus of magnetorheological fluid were tested.The test results show that the magnetorheological fluid has good performance and meets the requirements of the experiment.(2)The structure and Simulation of the multi-layer impedance modulation experiment platform is designed.First of all,based on the experimental requirements of impedance multilayer modulation,the design of the core components including electromagnet,fixed support frame and impedance modulation tube is completed.Secondly,by using the Ansoft Maxwell electromagnetic finite element simulation software,the distribution of the magnetic field and the magnetic field of the electromagnet hole are simulated.Finally,the actual parameters of the electromagnet are verified by using the Tesla meter.(3)The measurement and control system and the control strategy of the multi-layer modulation experiment platform are designed.First of all,according to the test requirement of impedance multilayer modulation,the measurement and control system of the experimental platform is built based on LabVIEW software.Secondly,in order to realize the intelligent control of the multilayer impedance modulation,the fuzzy control system is designed by using the fuzzy control software package of LabVIEW,Finally,the effectiveness of the fuzzy controller is verified by the experimental control system.(4)Experimental study on transmission characteristics of impedance period and quasi periodic vibration.First of all,based on the experimental platform,the impedance periodic structure and the quasi periodic structure of the magneto rheological fluid have been studied.Secondly,the experimental data of the variation of the vibration level drop with the magnetic field strength and vibration frequency are analyzed.The experimental results show that the vibration level drop of the impedance periodic structure and the quasi periodic structure are related to the magnetic field intensity and the exciting frequency,Among them,the vibration attenuation effect of Thue-Morse combination mode in quasi periodic structure is better than that of Fibonacci combination mode,The impedance of quasi periodic structure is better than that of impedance periodic structure.