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Seamless coupling of molecular dynamics and material point method via smoothed molecular dynamics
Author(s) -
He Nianfeng,
Liu Yan,
Zhang Xiong
Publication year - 2017
Publication title -
international journal for numerical methods in engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.421
H-Index - 168
eISSN - 1097-0207
pISSN - 0029-5981
DOI - 10.1002/nme.5543
Subject(s) - molecular dynamics , coupling (piping) , dynamics (music) , material point method , point (geometry) , statistical physics , classical mechanics , physics , computer science , finite element method , mechanical engineering , mathematics , engineering , geometry , quantum mechanics , acoustics , thermodynamics
Summary A concurrent multiscale method coupling molecular dynamics (MD) and continuum‐based material point method (MPM) is proposed. Seamless coupling is realized by utilizing smoothed molecular dynamics (SMD) method. One set of background mesh is used in SMD method. Atomic equations of motion are assembled onto mesh nodes, and atomic variables are updated with nodal increments. SMD allows much larger time step size than MD critical time step size but keeps nice global accuracy. SMD is similar to MD except for the mapping process between background mesh nodes and atoms. SMD and MPM share the feature using the background mesh to solve momentum equations and to update variables. So bridging MD and MPM via SMD is straightforward and concise. A recently proposed transition scheme based on frequency decomposition is adopted to suppress phonon reflection at MD‐SMD interface. The nodal equations in SMD–MPM interface region have contributions from both atoms and material points, which ensure the consistency between SMD region and MPM region. A multiple‐time‐step scheme is adopted for high efficiency. Numerical examples including wave propagation, bending, and crack propagation validate the proposed method, and the results show nice accuracy. The computational cost is greatly saved compared with pure MD computation. Copyright © 2017 John Wiley & Sons, Ltd.