The Role of Plasticity Theory on the Predicted Residual Stress Field of Weld Structures

Abstract:

Constitutive plasticity theory is commonly applied to the numerical analysis of welds in one of three ways: using an isotropic hardening model, a kinematic hardening model, or a mixed isotropic-kinematic hardening model. The choice of model is not entirely dependent on its numerical accuracy, however, as a lack of empirical data will often necessitate the use of a specific approach. The present paper seeks to identify the accuracy of each formalism through direct comparison of the predicted and actual post-weld residual stress field developed in a three-pass 316LN stainless steel slot weldment. From these comparisons, it is clear that while the isotropic hardening model tends to noticeably over-predict and the kinematic hardening model slightly under-predict the residual post-weld stress field, the results using a mixed hardening model are quantitatively accurate. Even though the kinematic hardening model generally provides more accurate results when compared to an isotropic hardening formalism, the latter might be a more appealing choice to engineers requiring a conservative design regarding weld residual stress.

• Periodical: Materials Science Forum (Volume 772)
• Pages: 65-71
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.772.65
• Online since: November 2013
• Authors: Ondrej Muránsky, Cory J. Hamelin, Mike C. Smith, Phillip J. Bendeich, Lyndon Edwards
• Keywords: Finite Element Analysis (FEA), Plasticity Theory, Residual Stress, Weld Modeling

References

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DOI: 10.1016/j.commatsci.2011.02.031

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