Nonlinear Characteristics Of Magnetostrictive Laminated Composite Devices

The laminate composite device made of new magnetostrictive material of Galfenol has the advantages such as high electromechanical coupling coefficient,high energy density and good mechanical properties,which made them has wide application prospect in driving,sensing and vibration generation.In this paper,first,the magnetostrictive materials and magnetoelectric composites are introduced.The research status of magnetostrictive laminate composite devices is reviewed.The development and application of magnetostrictive / piezoelectric composite devices are introduced emphatically.According to the Armstrong model,a three-dimensional eigennonlinear model based on anisotropy Galfenol is established.The simulation results are similar to the experimental data,and the validity of the model is verified.A static nonlinear model of the magnetostrive/PZT laminate composite actuator device was established by using the material model,the Euler-Bernoulli beam theory and the force/moment equilibrium equation.The force distribution inside the cantilever beam was calculated in detail The influence of the force distribution on the driving performance is analyzed.The thickness of the piezoelectric layer is obtained when the optimum driving effect is obtained,and the sensing signal-charge of the piezoelectric layer is calculated.The simulation results show that the model can describe the characteristics of cantilever in the laminate composite device which part of the magnetostrictive layer is compressive while part of it in tensile.Secondly,based on the Armstrong model,the constitutive equations of magnetostrictive materials,the theory of Euler-Bernoulli beam and the equivalent circuit method,the dynamic nonlinear model of a Galfenol/PZT laminated cantilever magnetoelectric sensor has been established.The relationship curves between the magnetoelectric coefficient and the varied operating conditions(such as the magnitude and the frequency of the magnetic field,the thickness ratio of Galfenol layer,and the applied prestress)have been calculated and analyzed.The theoretical analysis and simulation results show that the proposed model can describe the nonlinear magnetoelectric effect of the Galfenol/PZT cantilever device under the magnetic field and the prestress,and thus can provide a theoretical basis for designing the high-sensitivity sensors.Finally,based on the Armstrong model,the classical laminated plate theory and the constitutive relation of the magnetostrictive material,a two-dimension nonlinear magneto-mechanical coupling model of Galfenol-aluminum laminate composite force sensor is established.Under the effect of the bias magnetic field and the mechanical force in different direction the magnetic induction intensity and the corresponding sensitivity coefficient of the device are calculated by this model.The comparison between the calculated results and the experimental results shows that the model can provide reasonable data trends of the device under the excitation of stress and bias magnetic field,and it also can predict the influence of the excitation force and bias magnetic field on the performance of the device.These studies in this paper play an important role in the design,performance forecast and use of the magnetostrictive laminated devices.