Sensitivity of plastic response of defective pipeline girth welds to the stress-strain behaviour of base and weld metal

One of the key parameters influencing the acceptability of a pipeline girth weld defect subjected to remote plastic deformation is the strength mismatch between weld and base metal. However, no single definition exists for weld strength mismatch, as it can be defined either on the basis of yield str...

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Bibliographic Details
Published in:Journal of Offshore Mechanics and Arctic Engineering
Main Authors: Hertelé, Stijn, De Waele, Wim, Denys, Rudi, Verstraete, Matthias
Format: Article in Journal/Newspaper
Language:English
Published: 2013
Subjects:
Online Access:https://biblio.ugent.be/publication/3217415
http://hdl.handle.net/1854/LU-3217415
https://doi.org/10.1115/1.4007049
https://biblio.ugent.be/publication/3217415/file/3217427
Description
Summary:One of the key parameters influencing the acceptability of a pipeline girth weld defect subjected to remote plastic deformation is the strength mismatch between weld and base metal. However, no single definition exists for weld strength mismatch, as it can be defined either on the basis of yield stress, ultimate tensile stress or any intermediate flow stress. To investigate the relevance of such definitions, the authors have performed a series of analyses of curved wide plate tests, using a validated parametric finite element model. The results indicate that, whereas yield stress overmatch determines crack driving force for small plastic strains, ultimate tensile stress overmatch is the more important parameter for advanced plastic strains and determines the eventual failure mode. Further, the strain capacity and exact crack driving force curve are additionally determined by uniform elongation and crack growth resistance.