Mechanical of Cracks Screened by Dislocations
Abstract
We develop a general theorem for the force on singularities in an elastic two-dimensional medium in terms of the residues of the stress at the singularities. This theorem is then applied to a sharp crack screened by a cloud of dislocations. A total fracture criterion can then be derived in principle by specifying the local cleavage condition at the crack and the lattice resistance of the dislocations. The COD of the crack is shown to be given by the total screening Burgers vector of the dislocation cloud and the wake of a moving crack is discussed in terms of the resistance to moving the screening cloud. Finally, limitations of the model are discussed in terms of the geometrical effects on the cleavage plane caused by blunting the crack.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1982
- Accession Number
- ADA127086
Entities
People
- J. E. Sinclair
- R. M. Thomson
Organizations
- National Institute of Standards and Technology