Quartz Crystal To Reverse The Effects Of Simulation And Optimization

This thesis is supported by the National Natural Science Foundation of China (No.69974020) and the Scientific Research Foundation on Doctor's Subject of the Ministry of Education (No.98014016,10010141006). From aspect of application in engineering, knowledge from different cross disciplines such as Physics of Crystals, Physics of dielectrics, Thoery of elasticity, Numerical Analysis is utilized in the investigation on the torsional effect of piezoelectric. The complicated stress distribution of piezoelectric beam under torsion is investigated first by utilizing the torsion theory of anisotropic beam. Numerical solution is approached. Affiliated with piezoelectric effect of quartz, inner nonlinear electric polarization is calculated, equivalent body bound charges and sueface bound charges under torque are approached. Existence of torsional effect is testified by theoretical and experimental anlysis. The connection between the torque and the polarized charges is established.On the base of mathematical model of torsional effect, using multivariate unrestrained nonlinear optimization method, we research cutting angles and parameters of crosssection to get best torsional sensitivity. Result of optimization is supported by experiment. This is important for application in engineering.Based on MATLABprograms of simulation and optimization of torsional effect are included in appendix.