Evaluation of Stress Intensity Factor of Silicon Nitride with Bridge Indentation Crack by Caustic Method

The caustic method is an optical technique for determining the dynamic stress intensity factor of metals and plastics. In this study, the application of the caustic method to ceramics was investigated, and a technique is proposed here for determining the static stress intensity factor from a fine ca...

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Bibliographic Details
Published inJournal of the Ceramic Society of Japan Vol. 100; no. 1164; p. 1007
Main Authors OGASAWARA, Toshio, AKIBA, Tohru, OTANI, Keizo, AKIMUNE, Yoshio, SHIMIZU, Koji
Format Journal Article
LanguageEnglish
Published Tokyo Japan Science and Technology Agency 01.01.1992
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Summary:The caustic method is an optical technique for determining the dynamic stress intensity factor of metals and plastics. In this study, the application of the caustic method to ceramics was investigated, and a technique is proposed here for determining the static stress intensity factor from a fine caustic image of a ceramic specimen. The degree of deviation of parallelism and surface roughness of a specimen are important factors in obtaining a clear caustic image of ceramics. A reliable method for measuring the diameter of a caustic by image processing was proved to be effective in this experiment. The stress intensity factor of Si3N4 with a BI (bridge indentation) crack was evaluated, and the residual stress intensity factor caused by a Vickers indentation for a starter crack was examined using this method.
ISSN:1882-0743
1348-6535