Evaluation of X-Ray Radiography, Laser Shearography and I. R. Thermography in Defect Detection in Carbon Reinforced Polymer Composite Panels

Carbon fiber reinforced polymers, or so-called CFRPs, are widely used in different industries due to their unique properties, such as high strength-to-weight ratio. A common example of application of this material are composite planels that are used in the construction of composite panels curved and flats surfaces. Despite the excellent properties of these materials, a variety kinds of defects such as fiber disbonding or matrix cracks, affect their final performance. Therefore, the development of non-destructive inspection methods to identify defects in the parts made of this materials is very important. In this paper, samples of carbon fiber composites have been tested by X-ray radiography method. The results have been compared with two new NDT methods of digital shearography and infrared thermography. The results show that thermography is more successful in detecting many internal defects than the traditional X-ray radiography and also shearography. The results also show that in the curved geometry, which is not possible to complete the radiography test due to a limitation of some X-ray sources, the thermography method presents very acceptable results. It is also possible in many cases to use shearography method in flat samples to identify some kinds of defects, more successfully.