胶层对声表面波扭矩传感器特性影响分析

为了研究胶层对声表面波（SAW）扭矩传感器特性的影响，建立了包括胶层在内的扭矩敏感模型。利用微扰理论得到扭矩载荷与SAW谐振器频率偏移量之间的关系，采用剪滞理论分析了胶层对SAW扭矩灵敏度的影响；根据Maxwell模型建立了胶层松弛时间谱，得到了应变传递响应时间，通过数值计算分析了不同弹性模量、不同胶层厚度的响应时间。...

Influence of glue layer on the characteristics of SAW torque sensor

In order to study the influence of the glue layer on the characteristics of the surface acoustic wave (SAW) torque sensor, the torque sensitive model including glue layer was built. The relationship between SAW frequency shift and applied torque was obtained by virtue of the perturbation theory. The influence of glue layer strain transfer efficiency on the SAW torque sensitivity was analyzed by utilizing the shear lag theory. The glue layer relaxation time spectrum was built according to the model of Maxwell. The strain transfer response time of the glue layer with different elastic modulus and different thickness was analyzed through numerical calculation. The results show that the use of an glue layer with large elastic modulus and low viscosity coefficient is beneficial to reduce the response time of the glue layer and improve the torque measurement accuracy. The SAW torque sensor was packaged with MBond-200 according to the obtained results. The torque experiment was carried out to test the SAW sensor packaged with MBond-200. Within the measurement range of 1～100 Nm, linearity, repeatability and hysteresis of the 100 Nm SAW sensor were 0.68%, 1.27% and 1.01%, respectively. The experiment results indicate that the response time of selected glue has little influence on the measurement of the packaged SAW torque sensor.