 Similar to the longitudinal effect, the piezoelectric sensitivity occurring during the shear effect is independent of the size and shape of the piezoelectric element. The charge also occurs at the piezo element’s surfaces under load. In case of a load in x-direction applied to n elements connected mechanically in series and electrically in parallel, the charge is (for quartz and PiezoStar):
Qy = –2 · d11 · Fx · n
Shear-sensitive piezo elements are used for sensors measuring shear forces, torque and strain. They are used for the construction of sensors, the excellent performance of which is unaffected by temperature changes. As the strain varies in the sensor structure caused by changes in the temperature act in a direction perpendicular to the sensitive shear axis.
Other Piezoeffects:
d11: piezoelectric coefficient (–2.3 pC/N for quartz crystals)
Fx: force in x-direction
n: number of crystal discs
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