Image-enhanced backlighting: A new method of NDE for translucent composites

A quick and inexpensive method of nondestructive evaluation is described, based on image-enhanced backlighting. The method is capable of being applied to translucent composite materials such as Kevlar/epoxy and glass/epoxy to detect delamination with high resolution. The use of an enhancing dye also makes the method suitable for monitoring surface cracking. The technique has also been demonstrated to be an especially convenient method of observing in situ the growth of cracking and delamination damage as a composite is loaded, and is capable of monitoring the dynamic growth of damage in impact-loading situations. It has been shown to be appropriate for detecting barely visible damage resulting from either impact or static loading on thick laminated structures that even include honeycomb reinforcement. Graphs, Photomicrographs. 12 ref.--AA