Vibration Characteristics Of PZT/Terfenol-D Laminated Magnetoelectric Composite Structure

The magnetoelectric composite structure composed of magnetostrictive and piezoelectric materials has magnetoelectric coupling effect.It has an important application prospect in resonators,microwave devices,magnetic field sensors and other electronic devices.In this paper,the vibration characteristics of magnetoelectric composite structures are studied.Piezoelectric material PZT and magnetostrictive material Terfenol-D are used in the magnetoelectric composite structure.Terfenol-D shows nonlinear characteristics under the action of bias magnetic field.Magnetoelectric composite structure can produce many kinds of vibration modes under the action of external bias magnetic field,so it can be used as a sensor to test the external bias magnetic field.The relationship between the piezoelectric / piezomagnetic layer thickness ratio,aspect ratio and the vibration frequency of the magnetoelectric composite structure was studied by using the finite element software COMSOL.In addition,the effect of the electrode mass ratio on the characteristic frequency of the magnetoelectric composite structure was studied.The elastic constants,piezomagnetic constants and permeability constants of Terfenol-D are calculated by using the three-dimensional nonlinear magnetostrictive constitutive model proposed by Liu and Zheng.Based on the above three nonlinear parameters of Terfenol-D,the nonlinear relationship between the characteristic frequencies of the first-order bending vibration mode,the second-order bending vibration mode,the longitudinal stretching vibration mode and thickness shear vibration mode and the external magnetic field is simulated by using the finite element software COMSOL.The magnetoelectric composite structure specimens are prepared,the experimental platform is set up,and the simulation results are verified by experiments.The vibration frequency of the magnetoelectric composite structure changes with the external bias magnetic field.The Doppler laser vibration meter used in the experiment can measure the vibration of the magnetoelectric composite structure specimen by non-contact way,and can accurately measure the frequency of various vibration modes of the magnetoelectric composite structure specimen in the bias magnetic field.The experimental data obtained is in good agreement with the results of the finite element method,which also provides a new method for the measurement of the bias magnetic field.