Lamb wave-based quantitative identification of delamination in composite laminates

With such features as comparatively high strength-to-weight and stiffness-to-weight ratios, excellent capability of resisting corrosion and tailorable mechanical properties, the use of fibre-reinforced composite structures is increasing exponentially among various communities, offering significant weight saving and immense performance enhancement. However, composite structures are highly vulnerable to structural damage, in particular the delamination that can be introduced during manufacturing, tooling, processing or service. The occurrence of delamination is a great threat to the functional operation of composite structures, potentially leading to catastrophic failure of the whole structure if it accumulates above a critical extent. With safety regarded as the paramount factor for engineered structures, it is of vital importance to identify delamination in composite structures at an early stage so as to prevent any potential failure. This has motivated the rapid development of Non-Destructive Evaluation [”NDE-] techniques. Lamb waves, guided elastic waves in plate-like structures, have been examined as a means of establishing novel NDE tools, with laudable potential to cost-effectively identify delamination in composite structures.