Holographic Interferometry of CFRP Wing Tips

摘要

Holographic interferometry has been used to examine seven experimental Harrier ferry-tips primarily for defects in core to skin bonding. With increasing experience, the quality of the holograms recorded has improved, and although the interference patterns formed when the structure is warmed are often complicated, discontinuities are readily observed. A number of suspected defects have been found which are virtually undetectable using standard radiographic techniques. The most prominent of these are the long straight anomalies visible on all but the first sample examined; it is thought that they may be due to overlapping sheets of film adhesive but this has not yet been established with certainty. An ultrasonic scan of one sample also failed to detect it. Small circular patterns, possibly indicating debonds, have been found in a number of places. A group of large anomalies observed on one sample were confirmed by radiography. (Author)