Fig. 1. Schematic of interaction between the interstitial dislocation loop and expansion of micro-crack: (a) The model of micro-crack expansion without the effect of dislocation loop; (b) the model after including the effect of interstitial dislocation loop located at different positions.

Fig. 2. Expansion of free micro-crack under the effect of external stress: (a)−(c) Results at time of 1.0, 40.0, and 122.4 ps, respectively.

Fig. 3. Interaction between interstitial dislocation loop with radius R = 1.5 nm and micro-crack with distance to loop d = 1.5 nm. (a) to (c) are results at time of 15, 20, and 120 ps: (a) The initial stage with the formation of rugged crack tip; (b) the state with the formation of dislocation network after the interaction between loop and crack; (c) the final state with crack tip pinned by dislocation network located on XOZ plane.

Fig. 4. Interaction between interstitial dislocation loop with radius R = 1.5 nm and micro-crack with distance d = 3.0 nm to loop. (a) to (c) are results at time of 46, 75, and 122.6 ps: (a) The stage at the beginning of crack on slip plane by changing the expansion direction; (b) the state with the formation of dislocation network and 1/2 segments dominate the network; (c) the final state with crack expansion on slip plane, resulting in the fracture of material.

Fig. 5. Interaction between dislocation loop and micro-crack with d = 1.5 nm, R = 1.5 nm, and l = 1.5 nm:　(a) to (e) are results at time of 36.8, 48.6, 50.5, 95.0, and 122.6 ps, respectively.

Fig. 6. Interaction between dislocation loop and micro-crack with d = 1.5 nm and R = 3.0 nm: (a) to (d) are results at time of 29, 32, 80, and 123 ps.

Fig. 7. Results of interaction between dislocation loop and micro-crack with d = 5.5 nm, R = 3.0 nm after 122.5 ps.