Theoretical analyses of nonlinear magnetoelectric response in self-biased magnetostrictive/piezoelectric laminated composites

A novel nonlinear theoretical model including eddy-current effect and demagnetization effect is presented for predicting magnetoelectric (ME) response in self-biased magnetostrictive/piezoelectric composites with the magnetization-graded ferromagnetic materials. The model is developed based on the nonlinear constitutive relationships of magnetostrictive material, motion equation for the composite plate, and ME equivalent circuit method. In this theoretical model, the equivalent magnetic charge theory is used for analyzing the influence of magnetostrictive material FeCuNbSiB on the effective magnetic field inside the Terfenol-D and the non-zero piezomagnetic coefficient at zero bias, in which the interface coupling parameter £ and the magnetic field dependence of mechanical quality factor are taken into consideration. The theoretical results indicate that the variation of ME voltage coefficients with applied dc magnetic field are in good agreement with the experimental results both under low and resonant frequency conditions. It confirms the validity and reliability of the obtained nonlinear theoretical model. Furthermore, self-biased effect and the difference between the low frequency and resonant ME voltage coefficient with Hdc are discussed in details. The theoretical model plays an important role in the comprehensive understandings of dynamic ME response properties for self-biased laminate composites and the designing and fabricating ME devices.