基于Lamb波的改进概率法多层结构脱粘成像方法

Taking the solid rocket motor (SRM) shell built with stainless steel sheet, EPDM rubber and silicone layer as the object, the propagation of Lamb waves excited and received by piezoelectric ceramic plates(PZT) in shells is studied. Firstly, by setting up multiple sets of detection paths of piezoelectric sensors, the positioning results of the elliptical positioning method and the probability-based diagnostic imaging(PDI) method(improved PDI method) combined with the elliptical method under different demonding sizes were compared. Secondly, the improved PDI imaging methods under different positions and different probability values are compared. Finally, the imaging is verified through experiments. The results show that the improved PDI method based on PZT has higher accuracy and sensitivity over the elliptical positioning method and this method can be used to detect different debonding positions of SRM steel shell and insulation layer.