Development of the symmetrical laser shock test for weak bond inspection

This paper presents the LAser Shock Adhesion Test (LASAT) using symmetrical laser shocks. The study is part of ComBoNDT European project that develops new Non-Destructive Tests (NDT) to assess adherence properties of bonded composite structures. The technique, its principle, and the experimental setup are first presented. To evaluate the technology, a various contaminated CFRP assemblies are tested using the LASAT. For each case, their bonding strength is discriminated from a reference bonding strength. If the results are promising, they also rise a lot of questions concerning the state of the material post laser shot. A series of photomicrographs of tested areas are performed showing how the contamination impacts the crack propagation pattern. The study concludes on the technology capability to differentiate a correct assembly from a contaminated one.