ABSTRACT
Finite element method (FEM) can be adapted to smart structures with piezoelectric or magnetostrictive materials rather successfully when neither the applying electric field nor the generating AC strain is very large and when the linear relation can be assumed in the strain versus electric field or the strain versus stress. However, further improvement in the FEM algorithm is required for high-field or high-power drive of the piezoelectric system, where nonlinear and hysteretic characteristics should be taken into account, as well as heat generation. Ferroelectric materials tend to exhibit nonlinear and hysteretic characteristics in the relationships of polarization versus electric field, strain versus electric field, and strain versus stress. Elastic nonlinearity provides theoretically asymmetric impedance or strain spectrum under frequency sweep. Zheng et al. reported the heat generation from various sizes of multilayer type piezoelectric ceramic actuators. When using a statistical treatment of the domain-reversal mechanism, there are various computer simulation trials in polarization, magnetization, and strain curves.
