SKM 2023 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 4: Topical Session: Fundamentals of Fracture – Micromechanical Fracture Experiments
MM 4.1: Topical Talk
Montag, 27. März 2023, 10:15–10:45, SCH A 216
Crack and dislocations interactions: coupling DDD and XFEM — Elena Jover-Carrasco1, Erik Bitzek2, and •Marc Fivel1 — 1CNRS/SIMaP, Univ. Grenoble Alpes, Grenoble, France — 2MPIE, Computational Materials Design, Dusseldorf, Germany
The objective of this study is to build a numerical tool which could handle both cracks and dislocations in a dynamic manner. To do so, a 3D Discrete Dislocation Dynamics (DDD) code has been combined to the Extended Finite Element Method (X-FEM) via a strong coupling with the Finite Element software CAST3M. In the original FEM code, the crack advance is computed from the G-θ method which gives access to the stress intensity factors K. In this formalism, θ is the kinematically admissible virtual displacement of the crack and G is the energy release rate at the crack tip. When dislocations are present in the simulated box, they modify the evaluations of the energy and consequently the values of the derived stress intensity factors. These modifications are computed locally all along the crack front which is defined using level set functions. The crack front may locally change its direction of motion depending on the relative values of the stress intensity factors, especially KII. This will then lead to blunting effect of the crack tip.
In this presentation, full details of the coupling will be given. Test cases will then be presented where the behavior of a single dislocation in vicinity of a crack will be compared to atomistic simulations. Finally, large scale simulations of a mode I opening crack will be performed.