Non-Contact Detection of Debonding Defects in a Steel-Lead Adhesive Structure Using Laser Ultrasonic Technology
W.R. Meng and Z.G. Zhou
In order to detect the debonding defects in the steel-lead adhesive structure, and taking into account the particularity of its application, a new type of non-contact laser ultrasonic testing technology was adopted. The numerical model of steel-lead adhesive structure was established, the distribution law of temperature field on the surface of metal material irradiated by pulsed laser and the selection principle of laser parameters were analysed. The difference of laser ultrasonic signal between the intact bonding structure and debonding structure was analysed by transmission method and pulse reflection method respectively. And the transmission and reflection shear wave were selected to discriminate the debonding defects in the steel-lead adhesive structure. The results show that laser ultrasonic technology can realize the non-destructive testing of debonding defects in the steel-lead metal bonding structure, and has wide application prospect in weapon equipment, aerospace and other fields.
Keywords: Lasers, pulsed laser beam, ultrasound, steel-lead, adhesive structure, defects, nondestructive testing (NDT), numerical simulation, finite element method (FEM)