STRUCTURAL HEALTH MONITORING OF BONDED COMPOSITE JOINTS USING PIEZOCERAMICS

In this study, a Structural Health Monitoring (SHM) strategy is proposed in order to detect disbonds in a composite lap-joint. The structure un der study is composed of Carbon Fiber Reinforced Polymer (CFRP) bonded to a titanium plate and artificial disbonds are simulated by inserting Teflon tapes of various dimensions within the joint. In-situ inspection is ensured by piezoceramics (PZTs) bonded to the structure. Theor etical propagation and through-the-thickness strain distribution are first studied in order to d etermine damage sensitivity with respect to generated guided wave. The optimal configuration of the system in terms of mode and frequency selection, piezoceramic size, shape and inter-unit spacing is then validated using Finite Element Modeling (FEM) in 3D. Experimental study using variable angle wedges are first conducted in order to validate theoretical and numerical assumpt ions and Pitch-and-Catch measurements are then proposed in order to validate the efficient de tection of the damage and accurate estimation of its size.