Evaluation of Defects in FRP Composites by NDT Techniques

Abstract

The very fast developments in the technology of composite materials have led to newer and wider applications of such promising materials. Composite materials offer a number of potential advantages in the aerospace field, particularly in safety-critical structures such as primary and secondary aircraft components. The presence of several types of defects such as voids, inclusions, debonds, improper cure, and delamination are almost common during the manufacture and use of composite materials. The proper assessment of such defects is necessary to utilize the full potential of these materials. This present study has been taken up to detect and characterize such defects using a thermal imaging technique. The technique is found to be deterministic in the acceptable level for the assessment of defects in polymer composites. The thermography, ultrasonics (A-scan and C-scan), and also microscopy (photo-microscope and scanning electron microscope) methods were used here to assess the defects. The detection and characterization of the wide range of defects requires a number of specialized non-destructive methods. The proper assessment of defects is essential, particularly in safety-critical structures such as primary and secondary aircraft components, to avoid catastrophic failure.