Chapter 5 - Molecular dynamics

Abstract

The size effects in materials can be addressed by modeling them with full atomistic details using molecular dynamics (MD). Accordingly, the size effects governing mechanisms can be captured with the resolution of atomistic mechanisms. In this case, the simulation precision is controlled by the accuracy of the interatomic potentials. Although MD can capture the atomistic mechanisms, the simulation time scale and length scale is limited. However, increasing the efficiencies of the parallel MD codes along with rising new powerful Supercomputers expand the limits of time and size this method can address. In this chapter, due to the huge success of using MD to model the behavior of crystalline metals, the focus is on the investigation of size effects in crystalline metals. Various size effects studies of crystalline metals has been conducted. In this chapter, the focus is on the MD simulation of size effects during nanoindentation and micropillar compression experiments. In the case of nanoindentation, the elaborate description of the conventional and advanced experiments and theoretical models of the indentation size effects will be presented to clarify the necessity and value of MD simulation. Next, the atomistic simulation of the nanoindentation experiment will be presented. In the case of size effects during micropillar compression test, the focus in this chapter is solely on the MD simulation.