Microcracking in Piezoelectrics Weakens the Electromechanical Coupling and Changes Its Directionality

Microcracking in piezoelectrics is found to produce two major effects on the effective piezoelectric properties: it weakens the electromechanical coupling and it changes its "directionality", i.e. the direction of mechanical (electrical) response to the applied electrical (mechanical) loads. The latter effect implies that microcracking in piezoelectric sensors and actuators reduces the accuracy of the devices. We quantify the mentioned loss of accuracy. This can also be viewed as a quantification of the "piezoelectric fatigue".