A study of nano-indentation using coupled atomistic and discrete dislocation (CADD) modeling

Abstract

In this chapter the phenomenon of nano-indentation into a thin film bonded to a rigid substrate is simulated using a technique whereby a fully atomistic region is coupled to a continuum region. There are three unique features of the model—as compared to several other coupled techniques that are available. First, the continuum region contains any number of discrete dislocations, modeled as elastic defects. Second, these dislocations are mechanically coupled to one another and to the atomistic region, thus providing the atomistic region with the appropriate stress environment because of the long-range interaction with the dislocations. Finally, the method includes algorithms for automatically detecting and passing dislocations between the atomistic and continuum regions, taking care of the kinematics of slip at the atomistic/continuum interface. The coupled atomistics and discrete dislocations method is unique in that the continuum region can contain discrete dislocation. This allows dislocations to travel beyond the boundaries of the fully atomistic domain.