Assessment of TSA Technique for the Estimation of CFRP T-Joint Debonding

The structural health monitoring of composite structures represents an important tool for engineers to investigate and predict the mechanical behaviour of components in presence of defects or more in general damages. In this regard, non-destructive techniques are used for localising and characterising defects during operating conditions or maintenance. In the present research, the thermoelastic stress analysis (TSA) technique has been used as a non-destructive technique for evaluating the damage of aeronautical adhesive bonded CFRP T-joints made by automated fibre placement (AFP) process. In particular, the thermoelastic signal was used for determining the debonded areas produced by dynamic cyclic tests. The results in terms of the measured debonded area were compared to the well-established strain gauges and ultrasound techniques and the capability of the thermoelastic stress analysis to perform the structural health monitoring of T-joints has been demonstrated.