Pulse thrust loading process based on PVDF sensor

The paper presents a system to measure pulse instantaneous thrust using PVDF, which can respond to high frequency signal, as the sensitive element. System calibration is completed using separate Hopkinson pressure bars(SHPB) whose diameter is 37 mm. Result of calibration shows that piezoelectric characteristic of PVDF (5 mm×5 mm) is linear if the pressure is lower than 150 MPa. Piezoelectric coefficient of PVDF is about 20 pC/N after the calibrated data fitting. Thrust loading curve of parabolic laser thruster impacted by single pulse is acquired and the peak values of thrust are analyzed. Experimental results indicate that this test system can capture the characteristics of thrust loading and it is valuable for investigating laser thrusters and pulse detonation engines.