Hardening and non-associated flow NURBS plasticity

Coombs, W.M

Abstract

In numerical analysis the failure of engineering materials is controlled through specifying yield envelopes (or surfaces) that bound the allowable stress in the material. Simple examples include the prismatic von Mises (circle) and Tresca (hexagon) yield surfaces. However, each surface is distinct and requires a specific equation describing the shape of the surface to be formulated in each case. These equations impact on the numerical implementation (specifically relating to stress integration) of the models and therefore a separate algorithm must be constructed for each model. Recently a framework was proposed that allows any isotropic yield surface to be represented by a NURBS surface and the constitutive model formulated using the name numerical algorithm. This paper presents, for the first time, an extension to this framework to allow both hardening (expansion/contraction of the surfaces) and a non-associated plastic flow rule. As with previous work on NURBS plasticity, the constitutive framework is combined with an implicit backward-Euler-type stress integration algorithm. The numerical performance of the algorithm is demonstrated using both material point investigations and boundary value simulations.

Citation

Coombs, W. (2017, September). Hardening and non-associated flow NURBS plasticity. Presented at COMPLAS 2017: XIV International Conference on Computational Plasticity: Fundamentals and Applications., Barcelona, Spain

• Presentation Conference Type: Conference Paper (published)
• Conference Name: COMPLAS 2017: XIV International Conference on Computational Plasticity: Fundamentals and Applications.
• Start Date: Sep 5, 2017
• End Date: Sep 7, 2017
• Acceptance Date: Aug 25, 2017
• Publication Date: Sep 1, 2017
• Deposit Date: Aug 25, 2017
• Publicly Available Date: Aug 29, 2017
• Pages: 363-372
• Book Title: Proceedings of the XIV International Conference on Computational Plasticity. Fundamentals and Applications (COMPLAS 2017), 5-7 September 2017, Barcelona, Spain.
• Public URL: https://durham-repository.worktribe.com/output/1147983
• Publisher URL: http://congress.cimne.com/complas2017/frontal/Doc/EbookCOMPLAS2017.pdf