A CTOD-based mixed-mode fracture criterion

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20000276

Ma, F; Deng, X; Sutton, M A; Newman, Jr, J C

This paper presents a mixed-mode fracture criterion that uses the crack-tip opening displacement (CTOD) at a fixed distance behind the crack tip as the fracture parameter. This criterion is developed based on a detailed analysis of crack kinking in arbitrary directions. In essence, the proposed criterion states that crack growth occurs when the current CTOD reaches a critical value and the direction of crack growth is the direction that causes either the opening or the shearing CTOD component at the new crack tip to be the absolute maximum. Under linearly elastic conditions, it is shown that this criterion is equivalent to several commonly accepted mixed-mode criteria and predicts that crack growth will occur in a locally Mode I manner. Under elastic-plastic conditions, the mixed-mode CTOD criterion predicts that crack growth will be along either a local Mode I or a local Mode II direction. The prediction of the abrupt transition from Mode I-dominated crack growth to Mode II-dominated crack is in good agreement with the observation of the mixed-mode fracture test results from the Arcan specimens. Alternative forms or extensions of this criterion are also discussed.

• Research Organization: Univ. of South Carolina, Columbia, SC (US)
• OSTI ID: 20000276
• Report Number(s): CONF-9805206--; ISBN 0-8031-2602-6
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRACK PROPAGATION
ELASTICITY
FRACTURE MECHANICS
MATERIALS
PLASTICITY