Effect of void size and position on mechanical properties of nanotwinned metals under cyclic loading

In this work, molecular dynamic simulations (MDs) have been performed to study the deformation behavior of nanotwinned (NT) copper samples containing voids under cyclic loading. Results show that there are two stable states in the cyclic deformation process, and there is no obvious dislocation accumulation during the first stable state. When the void is in the twin lamella, it plays a softening role by emitting dislocations to promote the migration of twin boundaries (TBs), and the increase in the void size reduces the duration of the first stable state. When the void is through the TB, the TB limits the dislocation emission from the void, and the duration of the first stable state is not significantly affected by the void size. This study contributes to the understanding of the effect of defects on mechanical response of NT metals under cyclic loading.