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Dynamic fracture toughnesses of reaction-bonded silicon nitrideThe room-temperature dynamic fracture response of reaction-bonded silicon nitride is investigated using a hybrid experimental-numerical procedure. In this procedure, experimentally determined crack velocities are utilized to drive a dynamic finite-element code or dynamic finite-difference code in its generation mode in order to extract numerically the dynamic stress intensity factor of the fracturing specimen. Results show that the dynamic fracture toughness vs crack velocity relations of the two reaction-bonded silicon nitrides do not follow the general trend in those relations of brittle polymers and steel. A definite slow crack velocity during the initial phase of dynamic crack propagation is observed in reaction-bonded silicon nitride, which results in a nonunique dynamic fracture toughness vs crack velocity relation. In addition, it is found that a propagating crack will continue to propagate under a static stress intensity factor substantially lower than K(IC).
Document ID
19830040979
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Kobayashi, A. S.
(Washington Univ. Seattle, WA, United States)
Emery, A. F.
(Washington Univ. Seattle, WA, United States)
Liaw, B. M.
(Washington, University Seattle, WA, United States)
Date Acquired
August 11, 2013
Publication Date
February 1, 1983
Subject Category
Nonmetallic Materials
Accession Number
83A22197
Funding Number(s)
CONTRACT_GRANT: NGL-48-002-004
Distribution Limits
Public
Copyright
Other

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