A hybrid model for multiscale simulations of nanoindentation

A numerical model for multiscale simulations of nanoindentation has been established by coupling molecular dynamics (MD) simulations with finite element analysis. The multiscale simulations are performed for two-dimensional nanoindentation of a cylindrical indenter against a copper (1 1 1) substrate. Results show that the load-depth curves obtained from both multiscale and full MD simulations match each other reasonably well and no visible discontinuity of deformation is observed in the handshake region. In the beginning, the normal load increases gradually, corresponding to elastic substrate deformation, followed by sudden drops in load-depth curves, which are related to the nucleation and movement of dislocations. The simulations also reveal that indenter radius and indentation velocity significantly affect the nanoindentation process. By the use of multiscale method, the system size to be explored can be greatly expanded without increasing computational cost.