Effect of residual stresses on the crack-tip constraint in a modified boundary layer model

• Published in: International journal of solids and structures Vol. 46; no. 13; pp. 2629 - 2641
• Main Authors: Ren, X.B., Zhang, Z.L., Nyhus, B.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-06-2009
• Subjects: Cleavage fracture; Crack-tip constraint; Failure assessment; Residual stresses; Cleavage fracture; Failure assessment; Residual stresses; Crack-tip constraint
• ISSN: 0020-7683; 1879-2146
• DOI: 10.1016/j.ijsolstr.2009.02.009

Residual stresses play a crucial role in structural integrity assessment. In this study, a large cracked cylinder with a weld in the center is applied to investigate the effect of residual stresses on the crack-tip constraint. A modified boundary layer model with a remote displacement-controlled elastic
K-field and
T-stress under small scale yielding has been used to simulate the problem. A two-dimensional tensile residual stress field due to the weld is introduced into the model by the so-called eigenstrain method. It has been shown that the residual stresses can significantly elevate the crack-tip constraint and thus increase the probability for cleavage fracture. The constraint parameter
R introduced by the authors can be used to rank the crack-tip constraint induced by the bi-axial residual stresses. The
R value decreases with the increase in the applied
J-integral. The residual stress-induced constraint is also coupled with the
T-stress. The
R value becomes smaller with larger
T-stress.