FULLY PLASTIC CRACK-TIP FIELDS FOR PLANE-STRAIN SHALLOW-CRACKED SPECIMENS UNDER PURE BENDING

Citation
Yj. Kim et al., FULLY PLASTIC CRACK-TIP FIELDS FOR PLANE-STRAIN SHALLOW-CRACKED SPECIMENS UNDER PURE BENDING, International journal of fracture, 78(1), 1996, pp. 21-34
Citations number
21
Categorie Soggetti
Mechanics
ISSN journal
03769429
Volume
78
Issue
1
Year of publication
1996
Pages
21 - 34
Database
ISI
SICI code
0376-9429(1996)78:1<21:FPCFFP>2.0.ZU;2-U
Abstract
Detailed finite element (FE) analyses are performed to study the effec t of crack depth on crack-tip constraint at full yielding for pure ben ding of plane strain single-edge-cracked specimens. Analyses are based on small-strain formulations and perfect plasticity. The crack depth a/W ranges from 0.1 to 0.7, and the deformation is applied up to the l imiting state of full plasticity where crack-tip stresses reach steady -state limiting values. At load levels smaller than the limit load (co ntained yielding), the crack-tip constraint (stress triaxiality) gradu ally decreases as a/W decreases, but, at load levels close to the limi t load (or at the limit load), it decreases very sharply. In terms of a/W, tractable closed-form approximations for fully plastic crack-tip stress and strain fields are proposed, and fully plastic values of cra ck-tip stresses are re-phrased in terms of the Q-parameter [1,2]. The role of crack-tip strains on fracture of shallow-cracked bending speci mens is briefly discussed.