Innovative non-destructive evaluation and damage characterisation of composite aerostructures using thermography

The present study is concerned with the reliability and effectiveness of innovative non-destructive techniques for damage characterisation and evaluation of aerospace materials and structures. Infrared thermography (IrT) was used with the aim of assessing the integrity of bonded repair on aluminium substrates. For this purpose, artificial damage of various dimensions was introduced in composite laminates. These defects were successfully monitored with IrT using different imaging techniques. IrT was also employed for the online monitoring of the loaded structure. The real time evolution of progressive debonding owing to fatigue loading was monitored. No external thermal stimulation was necessary as the cyclic loading provided thermal excitation on the system. The experimental results provided evidence that the innovative technique was capable of qualitatively and quantitatively assessing the integrity of patched repairs. In other words, this technique can be efficiently employed for damage identification and quantification.