This paper demonstrates the non destructive evaluation on selected glassfiber reinforced plastic piping, for structural defects. The items selected for this presentation were constructed from fibreglass and polyester resin and include a tubular elbow, a tapered fibreglass tube and a hollow cube with pre-manufactured delaminations. This paper also introduces a Portable NDT unit which is capable of performing both Electronic Speckle Pattern Interferometry (ESPI) and Shearography, which are the chosen methods of inspection. The unit consists of a micro interferometer and laser assembly, optical fibers, video cameras, and a computer and frame store card. Using the NDT unit in both real-time mode and double-exposure mode, the ease with which ESPI and Shearography can be applied to the selected samples is demonstrated. The resultant interferograms are presented and their features highlighted. A discussion and interpretation of the fringe patterns supports the detected defect areas. The paper is concluded by comparing the two methods of inspection and discusses their advantages and limitations.
Publication Source: Trends in NDE Science & Technology; Proceedings of the 14th World Conference on Non-Destructive Testing, New Delhi, 8-13 December 1996.Vol. 3, pages 1521 - 1524 Publisher:Ashgate Publishing Company
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