Magnetic Circuit Analysis And Experimental Studies Of High Frequency Magnetostrictive Transducer

Rare earth giant magnetostrictive materials(such as Terfenol-D)are new functional materials developed in recent decades.It has the advantages of high energy density,large magnetostrictive strain,high coupling coefficient of magneto-mechanical and fast response speed,so it has a wide application prospect in underwater sonar,ocean exploration,precision machining,non-invasive detection,micro displacement drive,robot and other industries.At present,many researchers have used giant magnetostrictive materials in transducers,but few in the high-frequency field.In this paper,the high-frequency characteristics of giant magnetostrictive materials and the magnetic circuit of high-frequency magnetostrictive transducers have been studied in depth,providing theoretical basis for the wide application of high-frequency magnetostrictive transducers.In this paper,the development and application of giant magnetostrictive materials are introduced firstly,and the research status of transducer and magnetic circuit optimization at home and abroad as well as the problems to be solved are described.On this basis,the significance and main research contents of this topic are introduced.Secondly,the mechanism of magnetostriction,the high-frequency characteristics of giant magnetostrictive materials and the working principle of high-frequency magnetostrictive transducer are systematically analyzed.The magnetic circuit structure of high-frequency magnetostrictive transducer is given,and the method of designing the magnetic circuit structure is proposed,including the design of excitation coil,the design of giant magnetostrictive rod,the numerical solution of magnetic circuit magnetic field and the method of restraining magnetic leakage.Then,based on the finite element analysis method and COMSOL In the multiphysics software,the three-dimensional modeling and Simulation of giant magnetostrictive bar are carried out firstly,and the two typical cutting methods of giant magnetostrictive bar are compared.The simulation results show that the parallel cutting method can effectively restrain the magnetic loss of giant magnetostrictive bar at high frequency than the central cutting method,which proves the superiority of the cutting method.Then,the three-dimensional modeling and Simulation of the whole magnetic circuit of the energy converter are carried out,and the influence of the parameters of the upper and lower magnets on the mean and uniformity of the magnetic field of the magnetic circuit,such as the different radius,thickness,relative permeability and the axial length of the excitation coil,is studied.Then,the vibration modal analysis of the magnetic circuit is carried out.Finally,according to the optimized magnetic circuit structure,the experimental prototype of the high frequency magnetostrictive transducer is made,and the transducer experimental test system is built,and the vibration acceleration of the high frequency magnetostrictive transducer under different current amplitude and frequency is tested and analyzed.The experimental test data show that the actual resonance frequency value of the high frequency magnetostrictive transducer prototype is consistent with the theoretical calculation value.