Experimental study on active infrared thermography as a NDI tool for carbon–carbon composites

Active infrared thermographic technique was used as a non-destructive inspection (NDI) tool for carbon–carbon (C/C) composite with subsurface defects. A serial of representative carbon–carbon composite test samples, consisting of cutouts and cracks as defects were investigated experimentally and analyzed using finite element method (FEM). Both transient pulsed thermography and lock-in thermography technique were investigated. The capability of two techniques to detect subsurface defects of C/C composite and to provide information about the location of defect was analyzed. Results indicate that active thermographic technique is available for the subsurface defect detection of carbon–carbon composite.