Nonlinear resonant magnetoelectric coupling effect with thermal, stress and magnetic loadings in laminated composites

Since the magnetostrictive strain and magnetization of giant magnetostrictive materials exhibit enhanced nonlinear magneto-elasto-thermal coupling characteristics under the influence of bias magnetic field, prestress and temperature, this paper adopted a 1D nonlinear magnetostrictive constitutive and the linear piezoelectric constitutive relations combined with the equivalent circuit method to establish a 1D enhanced nonlinear magneto-elasto-thermal coupling resonant magnetoelectric (ME) model for Terfenol-D/PZT/Terfenol-D laminated composites. Without considering prestress, the comparisons of curves of resonant ME coefficient peak and its corresponding resonant frequency versus temperature between the theoretical results and experimental results are in good agreement both qualitatively and quantitatively. On this basis, this paper predicted variations in resonant ME coefficient and resonant frequency under different bias magnetic fields, prestresses and temperatures. These results show that the exerted compressive stress can be reduced so as to increase the resonant ME coefficient and lower the required bias magnetic field to the maximum of ME coefficient at relatively low and stable ambient temperatures; however, in extreme temperature environment, a larger compressive stress can be exerted to suppress the dramatic attenuation of ME effect caused by extreme temperature increases. Moreover, as temperature is increased, the resonant frequency tends to increase monotonically under different prestresses.