Transmitted light intensity as a nondestructive evaluation technique for glass/epoxy composite laminates

Selection of a nondestructive evaluation method for inspection of composite materials is a difficult process due to their multilithic nature and complex failure. Development of new techniques, which are more cost-effective and practical, are needed. Transmitted light intensity has the potential to satisfy these criteria. By measuring light intensity transmitted through a composite sample during fatigue testing, changes in the intensity were correlated to damage development within the sample. By applying image enhancement and analysis techniques, damage development due to matrix cracking and delamination, was detected and presented in images that were easy to understand.