Residual stresses influence the crack-tip driving force and constraint, and play a crucial role in the structural integrity assessment. The validity of the proposed parameter R for quantifying the effect of residual stresses on the crack-tip constraint has been investigated by means of a parameter study. A modified boundary layer (MBL) model has been applied into which the residual stresses have been introduced by means of the eigenstrain method.
R varies with geometry constraint levels; the higher geometry constraint, the weaker is the effect of residual stresses.
The size of the weld-metal region affects the value of the R parameter.
An increase in the external loading reduces the effect of the residual stresses.
External loading affects the geometry constraint as well as the residual stress constraint.
Residual stresses affect harder materials more strongly than softer materials.
Published February 19, 2008