Sensitivity of plastic response of defective pipeline girth welds to the stress-strain behavior 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
Main Authors: Hertelé, Stijn, De Waele, Wim, Denys, Rudi, Verstraete, Matthias
Format: Conference Object
Language:English
Published: American Society of Mechanical Engineers (ASME) 2011
Subjects:
Online Access:https://biblio.ugent.be/publication/1269468
http://hdl.handle.net/1854/LU-1269468
https://biblio.ugent.be/publication/1269468/file/1269469
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.