Identification of residual stress length scales in welds for fracture assessment

Residual stresses originate from the elastic accommodation of misfits between different regions in a structure. The interaction between the misfit and the restraint of the surrounding structure determines the magnitude of the resultant residual stress and its length-scale. This paper defines the residual stress length-scales that must be considered in engineering fracture mechanics analyses for welded joints by identifying the crack length-scale of concern. This information is used to estimate measurement length-scale requirements to quantify the stress field and the length-scale that must be represented in finite element weld residual stress simulations.