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.