Coarse-Grain Multi-Scale Modeling for Numerical Simulation of Plastic Behavior in Nano-Scale Material

Bahrololoumi Tabatabaei, Amir | 2018

445 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 50956 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Khoei, Amir Reza
  7. Abstract:
  8. In this paper, a multiscale coarse graining method is developed on the basis of the force matching theorem in order to model the nonlinear behavior of crystalline material. In this framework, two scales are involved, i.e. the nano- and meso-scales. In each of scales, molecular dynamic simulations are employed with this difference that the fine scale is modeled via embedded atom method many body potential and at the coarse scale the simulation is based on pairwise potential. In addition, the linkage between fine and coarse scales is achieved by data transfer between two scales; in a way that required information for coarse grain analyses, i.e. inter-particle potential and coarse scale initial configuration, are directly exploited from fine scale full atomistic simulation and transferred to coarse scale. In this study, coarse grained particles coordinates are attained by direct mapping on embedded atoms center of mass within the grain. Also, the inter-particle potential is considered as a pairwise with unknown parameters which are determined by force matching on net force of embedded atoms within the grain in the course of the atomistic simulation trajectory. The novelty of the current study is that the proposed pair-wise potential can be employed instead of many body EAM potential and therefore the computational costs are significantly reduced. Finally, several numerical examples are presented to illustrate validity and versatility of the proposed framework
  9. Keywords:
  10. Molecular Dynamics ; Multiscale Modeling ; Coarse Grained Model ; Numerical Simulation ; Force Matching

 Digital Object List