PVDF压力传感器的冲击压电特性研究

A Study of Impact Piezoelectric Property of PVDF Stress Gauges

PVDF薄膜是一种新型的聚合物压电材料。为了研究PVDF薄膜在低压和一维应变下的压电特性，利用立式Hopkinson压杆和一级轻气炮标定了自研制PVDF压力传感器的压电曲线，实验表明该应力传感器频响高，波形稳定，线性度良好，拟合灵敏度系数K值在0～20MPa和100-450MPa压力范围分别为14．96pC／N和11．9pC／N，可以基本满足动态冲击应力测试的要求。但由于PVDF薄膜的系数K受多方面的影响，定量分析有相当难度，建议使用跟实际工作状况相近的标定K值。

PVDF film is a new pattern of polymer piezoelectric materials. In order to study the piezoelectric properties of PVDF films under low pressure and one-dimensional strain, the impact piezoelectric property of PVDF stress gauges designed in this laboratory was calibrated by using a vertical Hopkinson press bar apparatus and an one-stage light gas gun. Experimental records show that it has high frequency response, steady waveform, and excellent linearity. The fitted sensitivity coefficients are 14. 96pC/N and 11. 9pC/N for the pressure range of 0 -20MPa and 100MPa-400MPa, respectively. Results show that PVDF stress gauges developed in this lab can basically meet the demand for impact stress measurement. However, because of extensive factors that affect the coefficient K of PVDF films, it is considerably difficult to quantitative analysis. It is recommended that the use of K value calibration should be compatible with the actual working conditions.