Research assistant, Brown UniversityGeneral Motors Research Laboratories, ProvidenceWarren, R.I.Mich.
Pages: 24 Published: Jan 1979
Plane strain crack advance under small-scale yielding conditions in elastic-perfectly plastic and power-law hardening materials is investigated numerically via the finite element method. Results indicate that the stress distribution ahead of a growing crack is essentially the same as that ahead of a stationary crack, and that the numerically evaluated steady-state crack tip profiles reflect a vertical tangent at the extending crack tip which corresponds to the theoretically predicted outline. It is found that the increment dδt in crack tip opening, when loads are increased at fixed crack length, seems to be uniquely related to dJ/σo irrespective of the amount of previous crack growth, and for increments dl of crack advance at constant external load, the incremental crack tip opening appears related to ln (J/σor) dl when evaluated at distance r from the tip. A discussion of proposed fracture parameters for continued crack growth (as opposed to growth initiation) is included.
stable crack growth, small-scale yielding, nonhardening and power-law hardening materials, fracture criteria for continued crack advance, crack propagation
Paper ID: STP35829S