Effects of residual stresses on fracture of welded pipes
- Univ. of Michigan, Ann Arbor, MI (United States). Mechanical Engineering and Applied Mechanics
- Battelle, Columbus, OH (United States)
Thermal residual stresses induced by multi-pass butt welding processes of stainless steel pipes are obtained by a thermoelastic-plastic finite element analysis with the assumption of axisymmetric conditions. After the welding processes, circumferential part-through cracks are introduced at the locations having the highest axial residual stress. Crack-tip parameters are sought for characterizing the crack-tip stress and deformation field under subsequent applied axial stresses. The computational results indicate that without residual stress mitigation processes, the residual stresses are quite large and the J integrals for several arbitrary paths are path dependent under the range of axial stresses. Therefore, J cannot be used as a characterizing parameter under the applied stresses. The results also show that, as the axial stress becomes large, the J integrals for different paths follow the same trend as those without residual stresses. This indicates that the residual stress effects become less significant when the deformation due to the applied axial stress becomes dominant. Finally, a computationally convenient parameter, the crack tip opening angle (CTOA), which can take into account the effects of residual stresses near the tip, is adopted for characterizing the crack tip deformation. The CTOA results suggest that with residual stresses the propensity for subcritical crack growth via a stress corrosion cracking or fatigue crack growth mechanism in welds may be higher than that without residual stresses.
- OSTI ID:
- 403191
- Report Number(s):
- CONF-960706-; ISBN 0-7918-1774-1; TRN: 97:000152
- Resource Relation:
- Conference: American Society of Mechanical Engineers (ASME) pressure vessels and piping conference, Montreal (Canada), 21-26 Jul 1996; Other Information: PBD: 1996; Related Information: Is Part Of Residual stresses in design, fabrication, assessment and repair. PVP-Volume 327; Warke, R.W. [ed.] [Edison Welding Inst., Columbus, OH (United States)]; Dong, P. [ed.] [Battelle Memorial Inst., Columbus, OH (United States)]; Dermenjian, A. [ed.] [Sargent and Lundy, Chicago, IL (United States)]; PB: 207 p.
- Country of Publication:
- United States
- Language:
- English
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