Effect of crack blunting on subsequent crack propagation
- Washington Univ., St. Louis, MO (United States). Dept. of Physics
- National Inst. of Standards and Technology, Gaithersburg, MD (United States)
Theories of toughness of materials depend on an understanding of the characteristic instabilities of the crack tip, and their possible interactions. In this paper the authors examine the effect of dislocation emission on subsequent cleavage of a crack and on further dislocation emission. The work is an extension of the previously published Lattice Greens Function methodology. They have developed a Cavity Greens Function describing a blunt crack and used it to study the effect of crack blunting under a range of different force laws. As the crack is blunted, they find a small but noticeable increase in the crack loading needed to propagate the crack. This effect may be of importance in materials where a dislocation source near the crack tip in a brittle material causes the crack to absorb anti-shielding dislocations, and thus cause a blunting of the crack. It is obviously also relevant to cracks in more ductile materials where the crack itself may emit dislocations.
- Sponsoring Organization:
- National Inst. of Standards and Technology, Gaithersburg, MD (United States); Office of Naval Research, Washington, DC (United States)
- OSTI ID:
- 488969
- Report Number(s):
- CONF-951155--; ISBN 1-55899-311-8
- Country of Publication:
- United States
- Language:
- English
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