<title>Modeling of nonlinear piezoceramics for structural actuation</title>

Abstract

An ab initio model describing the nonlinear behaviors of polycrystalline piezoceramics during polarization reversal is proposed. The model is based on a description of polarization reversal behaviors of a single piezoelectric crystallite in a piezoceramic. The polarization of the single crystallite can be switched among the six allowable directions in the lattice ifthe work done by the external electrical and/or mechanical loads exceeds the internal energy barriers. The piezoceramic is then modeled as an aggregate of these crystallites rotated into random orientations. The macroscopic responses of the piezoceramic were calculated in two ways. The first method is to calculate the average crystallite response in global coordinates. The second is to use Taylor expansions of the macroscopic strain and electrical displacement in terms of external loads and the internal alignment of the crystallites. Finally, the experimental results from free and clamped PZT wafers were compared with the model predictions.

Time dependent behavior of ferroelectric materials undergoing changes in their material properties with electric field and temperature

“…Schmidt (1981), Armdt et al (1984), Chan and Hagood (1994) and Fang and Li (1999) investigated electro-mechanical hysteresis responses of PLZT and PZT subject to cyclic electric fields, with amplitudes above the coercive electric field, applied in a quasi-static mode. Nonlinear behaviors were shown due to polarization switching.…”

Nonlinear Hysteretic Response of Piezoelectric Ceramics

“…In this case, we are interested in the response of piezoceramics below the coercive electric field such that the piezoceramics does not experience polarization switching. We also assume that applying electric fields along and opposite to the poling axis cause similar changes in the corresponding strains 6 . The nonlinear parameters show distortion in the hysteretic response from an ellipsoidal shape.…”

“…The second case starts with the electric field input in the direction of the 6 It is noted that the corresponding strain response in a polarized ferroelectric ceramics when the electric field is applied along the poling axis need not be the same as the strain output when the electric field is applied opposite to the poling axis. In most cases they are not the same, especially under a relative high magnitude of electric field as the process of polarization switching might occur even before it reaches the coercive electric field.…”

Nonlinear constitutive law for ferroelectric/ferroelastic material and its finite element realization

“…ferroelasticity were made by Chen and Hagood [1] , Hwang, Lynch and McMeeking [2] , Bassiouny, Ghaleb and Maugin [3] , and Bassiouny and Maugin [4] , based on the mechanisms of poling and domain-switching. Kamlah and Tsakmakis [5] , and Kamlah and Böhle [6] constructed a phenomenological nonlinear model for the ferroelectric and ferroelastic behavior of PZT ceramics.…”