Non-destructive evaluations of composite materials : 1. Delamination detection via holographic interferometryFunded under: FP3-MAT
An application of the method of laser holographic interferometry is described for the detection of impact induced damage in graphite-epoxy composites. Tests were performed on damaged specimens which had received one of three different levels of impact energy, as well as on virgin specimens. Real-time holography was applied while the specimens were thermally strained. For small temperature increases (1-3 C), irregular fringe patterns of closed shape were observed. They began to form at the impacted areas, and the more damaged the specimen, the earlier their appearance and the greater their extension. These fringes indicated deformation anomalies, and consequently the presence of defects. In contrast, the virgin specimens always produced regular fringe patterns. These results are compared with the C-scan images obtained from an ultrasonic inspection of the same specimens.
Bibliographic Reference: Article: Materials Engineering, Vol. 3 (1992) No. 2, pp. 341-349
Record Number: 199211320 / Last updated on: 1994-11-29
Original language: en
Available languages: en