13th International Conference on Fracture June 16–21, 2013, Beijing, China -3- 286 x 143 x 143 ų where a notch (dimensions 15 x 90 Ų) with a triangular notch tip was inserted along the (110) plane. Figure 1. Bcc iron cuboid 286 x 143 x 143 ų with a 15 x 90 Ų notch on a (110) plane. The 486000 atoms are color coded via von Mises stress (red =^ high stress, blue =^ low stress). Image by MegaMol™ [3]. Cyclic deformation of the simulation box was applied in the [001]-direction. Therefore, the z-component of the simulation cell was elongated with a constant rate of 5x10^-7 at each time step. After reaching a strain of seven percent we applied pressure at the same rate until we reach seven percent of strain in compression. This procedure was repeated continuously. Periodic boundary conditions were used in every direction. 2.2. Results and discussion Figure 2. Stress [MPa] in z-direction in terms of the time [ns] during cyclic loading of a nanostructure of a notched iron cuboid. System configurations at different times are depicted: blue are according to DXA [4] “defect surfaces”, red represent dislocations. The view is from lower left.
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