Incorporation of Residual Stress Effects into Fracture Assessments Via the Finite Element Method

This paper presents a finite element methodology for the incorporation of residual stress effects into fracture assessments of pressure vessel and piping components. The residual stress is determined through improved welding simulations. Following the welding simulation, interpolation is used to transfer the computed residual stresses onto fine meshes for the evaluation of J integrals. The finite element fracture assessment methodology is used as a baseline to evaluate several approximations to the residual stress field and appropriate analytic solutions for a 15.875 mm (5/8 in.) thick pipe with R/t=10, 25, and 50. The remote yield level approximation is found to be overconservative while the best approximation is the bending moment fit to the residual stress distribution.