固体发动机界面结构试件脱粘健康监测研究

Research on health monitoring of insulator/propellant interface debonding in solid rocket motor

以复合材料壳体和绝热层脱粘模型试件为对象,利用粘贴于壳体外表面的压电主动激励传感器,基于高频机电阻抗方法,对模拟药柱/绝热层界面脱粘的结构健康状态监测进行了数值仿真和实验研究,得出了不同脱粘损伤工况下的导纳频谱曲线,计算了能表征脱粘程度的平均绝对偏差损伤指标。结果表明,高频机电阻抗方法可利用粘贴于壳体外表面的压电传感器有效地识别内部结构的界面脱粘,相比于传统检测方法,能实现实时的结构健康监测,损伤指标能量化表征脱粘程度,实验采用的两种压电传感器中,MFC传感器较PZT传感器更适合于曲面固体发动机壳体脱粘检测,为开展实际工况下的固体发动机药柱结构界面脱粘损伤监检测工作提供理论与技术支撑。

In this research, through piezoelectric sensors which were surface-bonded to the composite case from the outside, pi- ezoelectric eleetromechanical impedance （EMI） structural health monitoring （SHM） technique was applied to identify the debond- ing condition of insulator/propellant interface structure using finite element analysis and experimental investigation. Mean absolute percentage deviation （MAPD） based damage index was obtained to quantify the changes in impedance spectrum for different debonding conditions.Numerical and experimental results demonstrate that the EMI technique can be used effectively for detecting the debonding damage in SRM.Compared with other detection method ,the EMI technique can realize real-time structural health mo- nitoring.MAPD damage index can quantitatively characterize the level of debonding damage.The MFC sensor is flexible, and more suitable for the curving SRM composite case surfaces than the PZT sensor.The EMI technique is expected to be useful for future ap- plication of real SRM＇s SHM.