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Title: Flow and plasticity via nonequilibrium molecular dynamics

The viscous flow of fluids and the plastic flow of solids, such as metals, are interesting from both the practical and the theoretical points of view. Atomistic molecular dynamics simulations provide a way of visualizing and understanding these flows in a detailed microscopic way. Simulations are necessarily carried out at relatively high rates of strain. For this reason they are ideally suited to the study of nonlinear flow phenomena: normal stresses induced by shear deformation, stress rotation, and the coupling of stress with heat flow, for instance. The simulations require appropriate boundary conditions, forces, and equations of motion. Newtonian mechanics is relatively inefficient for this simulation task. A modification, Nonequilibrium Molecular Dynamics, has been developed to simulate nonequilibrium flows. By now, many high-strain-rate rheological studies of flowing (viscous) fluids and (plastic) solids have been carried out. Here I describe the new methods used in the simulations and some results obtained in this way. A three-body shear-flow exercise is appended to make these ideas more concrete.
Authors:
Publication Date:
OSTI Identifier:
6217365
Report Number(s):
UCRL-90904; CONF-8405247-3
ON: DE85001011
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Conference
Resource Relation:
Conference: ISPRA EURATOM school on computer simulation in physical metallurgy, Ispra, Italy, 21 May 1984
Research Org:
Lawrence Livermore National Lab., CA (USA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; FLOW MODELS; MOLECULAR MODELS; VISCOUS FLOW; NONLINEAR PROBLEMS; PLASTICITY; SIMULATION; FLUID FLOW; MATHEMATICAL MODELS; MECHANICAL PROPERTIES; 640410* - Fluid Physics- General Fluid Dynamics