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The effect of thermally activated energy on the dislocation emission from a crack tip inBCC metal Mo is simulated in this paper.Based on the correlative reference model on which the flexi-ble displacement boundary scheme is introduced naturally,the simulation shows that as temperature in-creases the critical stress intensity factor for the first dislocation emission will decrease and the totalnumber of emitted dislocations increase for the same external load.The dislocation velocity and exten-sive distance among partial dislocations are not sensitive to temperature.After a dislocation emission,two different deformation states are observed,the stable and unstable deformation states.In the stabledeformation state,the nucleated dislocation will emit from the crack tip and piles up at a distance faraway from the crack tip,after that the new dislocation can not be nucleated unless the external load-ing increases.In the unstable deformation state,a number of dislocations can be emitted from thecrack tip continuously under the same external load.
The effect of thermally activated energy on the dislocation emission from a crack tip in BCC metal Mo is simulated in this paper. Based on the correlative reference model on which the flexi-ble displacement boundary scheme is presented naturally, the simulation shows that as temperature in- creases the critical stress intensity factor for the first dislocation emission will decrease and the total number of emitted dislocations increase for the same external load.The dislocation velocity and exten-sive distance among partial dislocations are not sensitive to temperature. After a dislocation emission, two different deformation states are observed, the stable and unstable deformation states. the stable disformation state, the nucleated dislocation will emit from the crack tip and piles up at a distance faraway from the crack tip, after that the new dislocation can not be nucleated unless the external load-ing increases.In the unstable deformation state, a number of dislocations can be emitted from thecrack tip continuously under the same external load.