PVDF传感器在液体压力激波测试中的应用

针对液体压力激波具有高温、高压和高应变的特点,研制了一种基于聚偏氟乙烯(PVDF)压电薄膜的液体压力激波传感器,并通过霍普金斯(Hopkinson)压杆对压电传感器的压电系数进行了精确标定,在此基础上构建了液体压力激波测试系统.在小压力幅值下,与水听器进行了对比测试试验,测试结果具有很高的吻合性,在满量程(0.1～1.0 MPa)内,与水听器偏差在5%范围内;大压力幅值下,通过对单元和多阵元液体压力激波发生器系统的测试,掌握了激励电压、脉冲频率、阵元个数等对激波的影响规律,为液体压力激波加工系统的改进和工程应用提供了试验依据.

PVDF Piezoelectric Film Transducer and Its Application for Measurement of Shock Wave in Liquid

According to the characteristics of high temperature, stress and strain of shock wave in liquid, a kind of PVDF piezoelectric film transducer was developed. Piezoelectric sensitive coefficient was calibrated by using the Hopkinson bar whereby a shock wave measurement system was established. The results of PVDF film transducer tallyed with those of hydrophone in the case of low pressure. The overall uncertainty was determined to be ±5% in the full range of 0.1～1.0 MPa. A series of experiments were investigated on the single element and array of elements shock wave generator under high pressure. The influence of physical parameters, such as voltage of power supply, frequency and numbers of elements was observed, which would be experimental basis of the further application for the shock wave generator and its improvements as well.