NDTnet 1998 Aug, Vol.3 No.8

Abstract

The paper is devoted to nondestructive testing of welded structures by means of optical holography. The major advantages of holograpfic method are: contactles, high sensitivity, visual control, no special demands for the object surface quality.
In case defect is present the value of surface local displacement is changed. The differences in displacements of defect and nondefect regions are determined on the pattern of interference fringes, which is obtained by means of holographic registry system. For this purpose small-sized thermoplastic instantaneous registration camera was created.
Small-sized holographic devices and instruments have been developed for measurement of residual stresses and for quality control of complicated structures using no special vibration isolations for an item under inspection.
The holographic devices and instruments developed allow to perform the nondestructive testing of welded joints and structures of metallic, plastic and composite materials, protective coating on turbine blades. Small-sized holographic equipment gives rise to reveal the zones of weakening and changes in mechanical properties of welded structures and forecast the fracture loads in objects of different shapes.
The photo of interference fringe patterns is the objective document that indicates the stress-strain state of object under investigation.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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