InfraRed Non-Destructive Testing of Glass Fibre Reinforced Composite Material for Detection of Sub-Surface Delamination

摘要

This work presents the defect detection capabilities of widely used pulsed, lock-in and recently introduced Barker coded infrared thermographic techniques, for characterization of glass fiber reinforced plastic specimen, with Teflon inserts of various lateral dimensions are placed at a given depth to simulate artificial delaminations. Further, delamination detection capabilities of these proposed schemes are compared, using frequency domain matched energy excitation scheme by taking signal to noise ratio into consideration as a figure of merit. The results obtained from the conventional phasegrams have been compared with the results obtained from pulse compression approach with Barker coded excitation.