Investigation of Off-Center Force Effect on Quartz Resonator Sensors, Using Nonlinear Finite Element Method

As quartz pressure sensors are widely used in oil and gas industry, in this study we have discussed the off-center force effect on their performance. As pressure sensors work based on force frequency effect, we investigated the effect of off-center force on frequency shift of AT-Cut resonator and force frequency effect, using a developed three dimensional nonlinear Finite Element Model (FEM). The Finite Element Model implemented based on Lagrangian equation proposed by Lee and Yong. The anisotropy and nonlinear governing equation of an AT-Cut quartz disk are implemented in model. Finally, the model has been compared and validated by previous experimental results. For the first time, the proposed nonlinear FEM predicted the two sinusoid behavior of quartz resonator. The off-center force frequency shift and the effect of geometry features on the performance of AT-Cut quartz, in different azimuthally angles, has been investigated. The effect of different design parameters and other parameters such as temperature was investigated. The results showed that the off-center force has considerable effects on force-frequency effect and therefore it can considerably influence on accuracy and sensitivity quartz pressure sensors.