Research on Natural Frequency of Piezoelectric Pressure Sensor Affected by Preload

The natural frequency of piezoelectric pressure sensors is seriously affected by preload, but there is currently a lack of relevant quantitative analysis, resulting in the lack of a corresponding theoretical basis for sensor design and packaging. In order to solve the above problems, based on the fractal theory, the relationship between the preload and the normal contact stiffness under different surface topography and element materials is deduced and simply verified by finite element simulation. Based on the sensor structure and size, a dynamics model is established, and the relationship between the preload and the natural frequency is obtained. Shock tube calibration experiments with different preload are used to verify the correctness of the relationship. The experimental results are similar to the theoretical calculations, proving the correctness and feasibility of the theory. The theoretical calculation results can be used for the selection of the preload and the estimation of the natural frequency of the actual piezoelectric pressure sensor, which is of great significance for the mass production of piezoelectric pressure sensors.