HOLOGRAPHIC INTERFEROMETRY ASSESSMENT: IN COMPOSITE AND ADHESIVELY BONDED STRUCTURAL DEFECTS

In any structural component where load path is diverted due to a change in section, i.e. a delaminated composite component, an adhesively bonded joint or ply drop-offs, and where out-of- plane stresses are induced, component surface displacements will occur. These out-of-plane surface displacements although relatively small, are indicative of internal structural problems that can be associated with component strength capacity limitations. This book discusses the application of a portable holographic interferometry testing system (PHITS) to study micro-deformations of a surface in a wide range of structural defects. The defects covered include delaminations, matrix cracks and matrix degradation due to heat, peel displacement behaviour in bonded lap-joints, debonded and weak bondlines. The results of this optical investigation have extended structural behaviour and mechanics understanding in all of the defect interaction.