A nonlinear magneto-mechanical-thermal-electric coupling model of Terfenol-D/PZT/Terfenol-D and Ni/PZT/Ni laminates

A nonlinear magneto-mechanical-thermo-electric coupling finite element model is established for the Terfenol-D/PZT and Ni/PZT laminates structure respectively, based on Maxwell electromagnetic equations and nonlinear constitutive equations of giant magnetostrictive materials. The magnetoelectric (ME) coefficients of the two laminates with considering the coupling stress or without considering the coupling stress are calculated respectively. The results indicate that the predicted values of ME coefficient of our model are very well in agreement with the experimental datas both in the low, intermediate and high magnetic field for the two kinds of materials structures at different temperatures (most of previous theoretical models just give the well comparison in low and intermediate field). The coupling stress has a significant effect on the ME coefficient for the Terfenol-D/PZT laminate, but little effect for the Ni/PZT laminate. The ME coefficient with considering coupling stress is smaller than that without considering coupling stress. Besides, the magnetic flux density, displacement and voltage distribution characteristics of ME laminates at different temperatures and pre-stresses are also detailed investigated. It has been shown a noteworthy phenomenon that the sensitivity of ME effect on temperature and/or pre-stress can be tuned by the pre-stress and/or temperature, respectively. Adjusting pre-stress can reduce the sensitivity of ME effect on temperature, which may promote the stability of ME devices operating in complex environments.