Investigation of the torsional effect of a piezoelectric quartz disc and torsion charge sensitivity

摘要

The torsional effect of a piezoelectric quartz disc and the distribution of torsion charge sensitivity are first investigated in this paper. The torsion stresses of a circular quartz disc are deduced by using the theory of anisotropic elasticity, and then through the Maxwell electromagnetic theory and piezoelectricity the distribution of bound volume and surface charge densities is computed. In order to make use of the torsional effect of a quartz disc and reduce the cross talk, the distribution of torsion charge sensitivity is investigated theoretically by means of coordination transformation and verified experimentally. Based on theoretical analyses of the bound charge densities and torsion charge sensitivity, the detection electrodes are effectively arranged on the surface of the piezoelectric disc. The theoretical and experimental results show that the charge measured is linear with the torque applied and the torsion quartz measuring cell is only sensitive to torque that is independent of axial and radial force.