摘要
对压力作用下沿[001]晶向极化的Pb(Mg_(1/3)Nb_(2/3))O_3-0.32PbTiO_3(PMN-0.32PT)弛豫型铁电单晶的应力应变行为进行了实验研究,实验结果表明铁电单晶〈001〉晶向的应力应变行为和铁电多晶有本质的不同,是传统的电畴翻转机理所难以解释的,所提出的极化旋转(相变)模型合理地解释了实验中观察到的现象;基于提出的极化旋转(相变)模型,采用细观力学方法建立了铁电单晶的细观本构模型.在模型中采用黏塑性公式描述铁电单晶可能的8个相变系统的相变行为.为了验证模型的可靠性,用该模型模拟了铁电单晶〈001〉晶向的应力应变实验曲线.计算表明,该模型能较好地模拟铁电单晶〈001〉晶向的相变行为.
The stress and strain properties of 〈001〉 oriented PMN-0.32PT relaxor ferroelectric single crystals are investigated in this paper. Obtained results show that the stress and strain behavior along 〈001〉 crystallographic direction is different from that of the ferroelectric polycrystal. Polarization rotation models are developed to explain the observed behaviors of PMN-0.32PT. Based on the experimental phase transformation mechanism of ferroelectric single crystal, a constitutive model of ferroelectric single crystal is proposed using micromechanical method. In the model, the phase transformation systems on 8 possible sliding planes are characterized by a viscoplastic law. The behavior of ferroelectric single crystal is then derived from phenomenal crystallographic theory through the transformation strain on sliding planes. The developed model is applied to simulate the experimental stress-strain curve of 〈001〉 oriented PMN-0.32PT. It is shown that the model can faithfully capture the key characteristics of the observed constitutive behavior of 〈001〉 oriented PMN-0.32PT.
出处
《力学学报》
EI
CSCD
北大核心
2007年第6期767-773,共7页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金(90205030
10472088
10425210)
全国优秀博士论文基金(200129)资助项目.~~
关键词
弛豫型铁电单晶
极化旋转(相变)
黏塑性模型
本构
细观力学
relaxor ferroelectric single crystal, polarization rotation （phase transformation）, viscoplastic model constitutive micro-mechanics
