应力条件下压电陶瓷损失机理分析

压电陶瓷材料中主要包括三种不同损失,即介电损失、机械损失和压电损失。为了研究这三种损失的机理并由实验方法分别测量这三种损失的大小,本文利用复参数理论对压电陶瓷材料(PZT-4)建立了使用复参数表示的损失理论模型;讨论了三种损失的物理意义并推导了通过测量等效参数分别计算三种损失的具体方法;测量了在应力条件下压电陶瓷等效电路中的谐振点阻抗、反谐振点阻抗、串连电阻和品质因素的变化情况并以此计算出三种损失随应力的变化。

Loss Mechanisms of Piezoelectric Ceramics Under Stress

Losses in piezoelectrics are considered in general resulting from three different mechanisms, dielectric, mechanical and piezoelectric losses. To measure the three kinds of losses separately, complex coefficients are introduced to establish the loss mechanism models. The methods of measuring the losses via experiments are proposed to verify the discussions of the physical mechanism of the losses. The resonant impedance, anti-resonant impedance, series resistance and quality coefficient of the equivalent circuit of ceramic under stress, are measured, and the loss variations with the stress are calculated comparatively.