| 1. |
- Meyer, Knut Andreas, 1990, et al.
(författare)
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A distortional hardening model for finite plasticity
- 2021
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Ingår i: International Journal of Solids and Structures. - : Elsevier BV. - 0020-7683. ; 232
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Tidskriftsartikel (refereegranskat)abstract
- Plastic anisotropy may strongly affect the stress and strain response in metals subjected to multiaxial cyclic loading. This anisotropy evolves due to various microstructural features. We first use simple models to study how such features result in evolving plastic anisotropy. A subsequent analysis of existing distortional hardening models highlights the difference between stress- and strain-driven models. Following this analysis, we conclude that the stress-driven approach is most suitable and propose an improved stress-driven model. It is thermodynamically consistent and guarantees yield surface convexity. Many distortional hardening models in the literature do not fulfill the latter. In contrast, the model proposed in this work has a convex yield surface independent of its parameter values. Experimental results, considering yield surface evolution after large shear strains, are used to assess the model's performance. We carefully analyze the experiments in the finite strain setting, showing how the numerical results can be compared with the experimental results. The new model fits the experimental results significantly better than its predecessor without introducing additional material parameters.
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| 2. |
- Meyer, Knut Andreas, 1990, et al.
(författare)
-
Efficient 3d finite element modeling of cyclic elasto-plastic rolling contact
- 2021
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Ingår i: Tribology International. - : Elsevier BV. - 0301-679X. ; 161
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Tidskriftsartikel (refereegranskat)abstract
- Railway rails accumulate large plastic deformations due to cyclic rolling contact loading. The plastic deformations alter the rail geometry, affect material behavior, and cause crack formation and growth. The complex interactions between these phenomena require high fidelity simulations to be understood. 3d finite element simulations are accurate, but their computational cost limits the possible number of simulated cycles. We propose a cyclic finite element simulation in which the wheel and rail remain in contact throughout the simulation. It uses periodic boundary conditions, shadow elements, and model reductions. Compared to previous work, it is 25 times faster. The method is available as an open-source plugin to Abaqus, enabling other researchers to study rolling contact loading coupled with large plastic deformations.
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