A thermographic comparison study for the assessment of composite patches

Transient thermography (TT) was used for the non-destructive assessment of repaired aircraft carbon or boron composite panels, as well as of composite patches enclosing a fibre optic across their width. The panels were assessed using two different thermographic evaluation systems. In all situations the subsurface features, i.e. defects and/or the fibre optics, were positioned intentionally. After detecting the subsurface features, representative thermal images obtained from the investigation underwent quantitative image analysis. Finally, mathematical thermal modelling was also attempted in order to obtain information about the defects in space and in time.