Hierarchical computational approaches of the effects of interstitial and vacancy loops on plastic deformation

Tsuru, Tomohito   ; Aoyagi, Yoshiteru; Kaji, Yoshiyuki  

Dislocation channeling observed in irradiated metals is generated as the result of strain localization and it has been thought to be the dominant stress factor in irradiation assisted stress corrosion cracking. In the present study, a hierarchical computational modeling based on atomistic and continuum simulations were constructed to describe the fundamental characteristics of the plastic deformation in irradiated materials. Several anomalous defects are introduced under irradiation. At first individual influences of the irradiation defects on plastic deformation can be identified by atomistic simulations. Then local interaction events between glide dislocation and irradiation defects were introduced into the crystal plasticity finite element analysis. We found that softening after the first yield event observed in experimental study is caused by annihilation of irradiation defects resulting from unfaulting by dislocation sweeping.