Abstract
Residual stresses may reduce the apparent ductile fracture toughness of structural steels. However, prior load excursions may alleviate this reduction. Effects of several load histories on ductile fracture initiation are investigated using finite element analyses of compact tension specimens. The Gurson-Tvergaard-Needleman micromechanical model is used, where void volume fraction in the crack tip vicinity measures local damage. Analysis without load history, with three tensile residual stress levels, and three tensile overload levels after each residual stress are performed. Evolutions of several global and local parameters with local damage are presented. Ductile fracture initiation is assumed when local damage attains a critical value. The reduction of fracture toughness is shown to increase with increasing residual stress levels. Departure from this trend is observed for high residual stresses and is explained by damage-band formation. Increasing overloads are shown to increasingly mitigate the detrimental effects of residual stress.
Original language | English |
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Title of host publication | 12th International Conference on Fracture 2009, ICF-12|Int. Conf. Fract., ICF |
Place of Publication | Canada |
Publisher | Curran Associates Incorporated |
Pages | 5903-5912 |
Number of pages | 9 |
Volume | 8 |
ISBN (Print) | 9781617382277 |
Publication status | Published - 2009 |
Event | 12th International Conference on Fracture 2009, ICF-12 - Ottawa, ON, Canada Duration: 12 Jul 2009 → 17 Jul 2009 |
Conference
Conference | 12th International Conference on Fracture 2009, ICF-12 |
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Country/Territory | Canada |
City | Ottawa, ON |
Period | 12/07/09 → 17/07/09 |