Non-destructive evaluation of composite materials : Delamination detection via holographic interferometryFunded under: JRC-RELISTRU C
An application of laser holographic interferometry for the detection of impact induced damage in graphite-epoxy composites is described. Damaged specimens, which had received three different levels of impact energy, were tested as well as undamaged 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 was, the sooner they appeared and extended. These fringes are indicative of deformation anomalies and, consequently, of the presence of defects. In contrast, the virgin specimens always produced regular fringe patterns. These results compare favourably with the C-scan images obtained from an ultrasonic inspection of the same specimens.
Bibliographic Reference: Paper presented: Introductory Workshop on Composite Materials, Trieste (IT), Oct. 28 - Nov. 8, 1991
Availability: Available from (1) as Paper EN 36515 ORA
Record Number: 199210080 / Last updated on: 1994-12-02
Original language: en
Available languages: en