Open Source Contour Method Analysis for Assessing Residual Stress in Weldments

Roy, M. J.; Stoyanov, N. and Moat, R. J. (2024). Open Source Contour Method Analysis for Assessing Residual Stress in Weldments. In: Franck, Christian; Kasza, Karen; Estrada, Jon; De Finis, Rosa; Ólafsson, Geir; Gururaja, Suhasini; Furmanski, Jevan; Forster, Aaron; Kolluru, Pavan; Prime, Mike; Berfield, Tom and Aydiner, Cahit eds. Challenges in Mechanics of Biological Systems and Materials, Thermomechanics and Infrared Imaging, Time Dependent Materials and Residual Stress, Volume 2. SEM 2023. Conference Proceedings of the Society for Experimental Mechanics Series ((CPSEMS)). Cham: Springer, pp. 21–29.

DOI: https://doi.org/10.1007/978-3-031-50470-9_4

Abstract

The contour method for assessing residual stress is a widely accepted technique and has been widely applied to validate and verify modelling predictions of welding processes since its inception 20 years ago. Briefly, it comprises the stress-free cutting of a body containing residual stress. Then, using the resulting averaged distortion measured from both cut faces, the calculation of the elastic loading to “force” the cut face “flat” is possible. However, a wider application as compared to other residual stress assessment techniques has been somewhat limited due to the absence of a common computational framework to process experimental data. This is at odds with the relatively accessible equipment requirements to generate this data: a wire electrodischarge machining (EDM) facility for cutting and a coordinate measurement machine or surface profilometer to capture the resulting deformation of the cut surfaces. In the present work, an open-source platform is presented that accommodates the full analysis work flow, from registration of surface profiles from each side of the cut, alignment and averaging of these profiles, numerical fitting of this surface, and finite element pre- and post-processing to recover a contour plot of the residual stress. Programmed in Python, this has been accomplished via a graphical user interface for initial preprocessing steps, followed by close integration of commercial finite element code (Abaqus) and open-source equivalents (Gmsh, CalculiX). Called pyCM (Python Contour Method), the overall analysis sequence is described employing a thick-section weld in pressure vessel steel (SA533), as well as showing that the results stemming from this tool employing either Abaqus or CalculiX are identical. Further advantages of pyCM will be discussed including diminished cost of accessing the technique and the ease of sharing of results and analysis strategies among practitioners. Factors, which necessitate these decisions, are inherent to the technique, and the present contribution lends itself to making the results obtained by the contour method more transparent.

Viewing alternatives

Metrics

Item Actions

Export

You can export this page using these formats Digital Object Identifier - DOI