Transverse optical fuse for composite damage detection

The application of advanced composite materials to critical aerospace structures requires the development of routine, in-service inspection techniques to detect low energy impact damage. A transverse optical fuse technique for damage detection in laminated composites is presented here. Short lengths of optical fiber can be embedded through the thickness of a graphite/epoxy laminate during the fabrication process. The fibers act as optical fuses, which break in areas of low energy impact damage. If a regular array of fibers is emplaced, the pattern of light transmission through the composite can be used to identify areas of low energy impact damage since unbroken fibers transmit light while broken fibers dot not