含随机分布缺陷的多晶铁电材料的有效电弹性能

针对铁电材料含有随机分布缺陷以及微结构在外场作用下发生变化的特点，建立起一个细观统计力学模型，考虑到缺陷和酶极化转动之间的相互影响，利用细观力学方法－Eshelby等效夹杂法和Mori-Tanaka的平均理论，具体分析了所含缺陷以及外场对铁电材料有效电弹性能和模量的影响。针对BaTiO3铁电陶瓷的有效电弹性能与常数的预报结果表明了缺陷的存在将增强材料的压电性能。

THE EFFECTIVE ELECTROELASTIC PROPERTIES OF POLYCRYSTALLINE FERROELECTRIC CERAMICS WITH RANDOMLY ORIENTED DEFECTS

in terms of the microstructure characteristics of polycrystalline ferroelectric ceramics, a statistical micromechanics model is employed to predict the effective electroelastic properties of polycrystalline ferroelectric ceramics with randomly oriented defects, such as voids and mi-crocracks, by the method of Eshelby's equivalent inclusion theory and Mori-Tanaka's mean field concept. The model incorporates the effects of crystallographic domain switching under external mechanical or electric field and the randomly oriented defects on the macroscopic behaviors of the polycrystalline ferroelectric ceramics. The analytical predictions of BaTiO_3 polycrystalline ceramics are shown that the defects can enhance the effective piezoelectric properties but reduce the elastic properties, which are consistent with the experimental results.