A coarse-graining approach for modeling nonlinear mechanical behavior of FCC nano-crystals

摘要

The ever-increasing growth of nano-technology has elevated the necessity for development of new computational methods that are capable of evaluating large systems at nano-scale. The existing techniques, such as the molecular dynamics, lack the ability to simulate large systems of practical size and time scales. In order to provide a realistic simulation of large models, the multi-scale methods such as coarse-graining, have therefore become very popular. The coarse-grained models have mostly been used to simulate large biomolecules, such as proteins, lipids, DNA and polymers. In this paper, the Iterative Boltzmann Inversion (IBI) coarse-graining technique is applied to FCC nano-crystals; the successful application of this technique enables the simulation of large metallic models, the simulation of which using conventional molecular dynamics methods would be time and energy consuming. The application process consists of two steps. In the first step, the IBI method is employed to develop an interatomic potential for the all-atom system. The efficiency of generated potential is, then, compared with EAM potential. Once the efficiency of IBI method is established in producing a proper potential to simulate all-atom behavior, the mechanical behavior of the coarse-grained system is compared, in the second step, with the behavior of all-atom system. Finally, several numerical simulations are provided to investigate the efficiency of proposed coarse-graining technique in predicting the nonlinear mechanical behavior of FCC nano-crystals.