Integrated peak spectral intensity for in situ crack detection
โ Scribed by C.J. Tay; H.M. Shang; M.R. Sajan
- Book ID
- 104160087
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 523 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0030-3992
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โฆ Synopsis
This paper presents an integrated peak spectral intensity method for in situ detection of a fatigue crack in a metallic material. The method employs a laser beam to illuminate the notch root of a central slot machined on test specimens. The diffracted images are digitized, recorded and processed on a personal computer. Subsequent image processing and analysis yield information from which fatigue crack initiation on the specimen is determined. The technique is applied to aluminium alloy specimens subjected to a cyclic tensile load with a constant stress amplitude. Unlike previous techniques, the present technique enables recording of speckle images and the subsequent detection of fatigue crack initiation without the necessity of unloading the test specimen from the testing machine.
๐ SIMILAR VOLUMES
Stress intensity factors have been determined directly for certain special crack problems with the help of J or other path-independent integrals. Such procedures have not been used successfully in what are perhaps the most classical of all crack problems: those in two dimensions involving a crack of
This paper comments on some of the different numerical techniques commonly employed in evaluating Cauchy singular integrals of the first kind; e.g. as pertaining to 2D through cracks in a brittle material undergoing Mode I loading. In addition, a different more direct method is proposed here. Also,