Design Optimization and Dynamic Characteristic Study of Piezoelectric Vibration Sensors

Speed increases in train operation impose increasingly stringent requirements for the safe and stable operation of various train components. Vibration sensors for health monitoring of critical components in running gears have emerged accordingly. However, constrained by the harsh operating environments onboard and the need to maintain compatible with existing sensor interfaces, in-service vibration sensors exhibit limited frequency ranges. To address this limitation, this paper proposes a design for piezoelectric vibration sensors tailored for motor health monitoring on high-speed trains, featuring broad frequency ranges. To extend the frequency range and minimize sensor noise, this design incorporates a shear-type structure for assembling the piezoelectric materials. Through shape optimization, the product structure ensures a higher natural frequency. Additional design analysis focused on the signal processing circuit and noise optimization, yielding effective solutions for enhancing the sensor's dynamic characteristics. Subsequent testing demonstrated a frequency response range of up to 8 kHz for the optimized piezoelectric vibration sensor design, meeting the current high-frequency vibration testing requirements for high-speed trains.