The Effect of Constraint on Ductile Crack Growth for Anisotropy Evaluation of X100 Pipeline Steels

Plastic anisotropy shows an obvious effect on ductile fracture (static and dynamic) of X100 pipeline steel. The crack tip constraint caused by crack depth and specimen geometry influences the crack growth resistance as well. In a recent attempt to identify the effect of plastic anisotropy on crack growth resistance of X100 pipeline steel, a dependent relationship between the anisotropy and crack tip constraint has been observed. In this study, the complete Gurson model is used to study the effects of constraint on ductile crack growth behavior to evaluate anisotropy of X100 pipeline steel. Crack growth resistance curves for plane strain, mode I crack growth under large scale yielding conditions have been computed. SENT specimens with different crack depths have been selected. It has been found that the influence of anisotropy on ductile fracture resistance is depended on the crack tip constraint. (C) 2014 Published by Elsevier Ltd.