Characterization of mechanical properties in weld metal using inverse modelling

• Main Authors: Beddeleem, Jurgen, De Waele, Wim, Hertelé, Stijn, Verstraete, Matthias, Van Minnebruggen, Koen
• Format: Conference Object
• Language: English
• Published: Ghent University, Laboratory Soete 2012
• Subjects: Technology and Engineering; notched tensile test; finite element analysis; mechanical properties; inverse modelling; permafrost
• Online Access: https://biblio.ugent.be/publication/3130436; http://hdl.handle.net/1854/LU-3130436; https://biblio.ugent.be/publication/3130436/file/3130457

Nowadays, more oil and gas transportation pipelines are constructed in areas with permafrost and/or higher seismic activity. These pipelines can be subjected to longitudinal plastic deformations necessitating a strain based design. Since girth- and seam welds are critical in terms of structural integrity, it is desirable to know their mechanical properties. In a strain based design context, the accurate determination of yield strength and hardening are necessary. A longitudinally extracted (is parallel to the pipe axis) specimen notched at the weld region and loaded in tension, in combination with inverse modelling is assumed to be a valuable tool to determine these properties. This notched cross weld test ensures that the largest deformations will occur at the weld, thereby allowing to fully determine the stress-strain behaviour of the weld metal. Inverse modelling combines experimental full-field strain data with numerical simulations to determine the constitutive parameters. Strains will be measured experimentally and compared with simulated data. By minimizing their difference, i.e. a certain cost function, a correspondence is found and the desired parameters are determined. This paper focuses on one aspect of the inverse modelling framework, the development of the parametric finite element model.