Holographic Interferometry of CFRP Honeycomb Panels.

The report describes an investigation into the use of holographic interferometry for the location of areas of faulty bonding in honeycomb sandwich panels with carbon-fibre-reinforced plastic skins. It was found that such faults could be reliable detected by a live fringe technique characteristic ring patterns corresponding to faults were readily produced by small temperature changes, and were quite distinct from fringes caused by whole-body movement. Current work indicates that the method could be applied to actual structures, although faults are more difficult to identify against complicated background patterns.