Details

Autor(en) / Beteiligte

• Hauf, Dagmar E.
• Parks, David M.
• Lee, Hyungyil

Titel

A modified effective crack-length formulation in elastic-plastic fracture mechanics

Ist Teil von

• Mechanics of materials, 1995-06, Vol.20 (4), p.273-289

Ort / Verlag

Lausanne: Elsevier Ltd

Erscheinungsjahr

1995

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• In examining the performance of standard effective crack-length formulations, the authors noted quantitative accuracy up to “high” fractions of limit load under loading conditions for which the elastic T-stress was non-negative, while a pronounced deviation from the corresponding continuum elastic-plastic plane-strain finite-element solutions was seen in shallow-cracked geometries having negative T-stress. This trend can be rationalized by noting that, under modified boundary layer ( K I and T) loading, the maximum plastic zone radius strongly increases as the T-stress decreases from zero (J.R. Rice (1974), J. Mech. Phys. Solids 22, 17–26; S.G. Larsson and A.J. Carlsson (1973), J. Mech. Phys. Solids 21, 263–277; N.P. O'Dowd and C.F. Shih (1991), J. Mech. Phys. Solids 39(8), 989–1015.) Accordingly, we formulate a modified effective crack length to account for the effects of the elastic T-stress. The new formulation consistently extends the load range for which accurate predictions of compliance, J-integral, and crack-tip constraint are obtained in several plane strain specimen geometries. The magnitude of influence of the T-stress varies with specimen type and relative crack depth. The greatest “improvement” to standard effective crack length approximations occurs in specimens of “moderately” negative T-stress.