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A generalized continuum theory and Its relation to micromorphic theory / Youping Chen in Journal of engineering mechanics, Vol. 135 N°3 (Mars 2009) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 135 N°3 (Mars 2009) . - pp. 149-155 Titre : A generalized continuum theory and Its relation to micromorphic theory Type de document : texte imprimé Auteurs : Youping Chen, Auteur ; James Lee, Auteur ; Liming Xiong, Auteur Article en page(s) : pp. 149-155 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Continuum  mechanics  Theories. Résumé : Classic continuum mechanics views a crystal as a homogeneous and continuous medium, in which the basic structural unit of the crystal is taken without structure and is idealized as point mass. Micromorphic theory views a material as a continuous collection of deformable point particles; each particle has finite size and additional nine internal degrees of freedom describing the stretches and rotations of the particle. This paper presents a multiscale field theory that views a crystalline material as a continuous collection of lattice points, while embedded within each point is a group of discrete atoms. The atomistic formulation of the field theory is briefly introduced. Its relation with the well-known micromorphic theory is derived. The applicability of the classical continuum theory, micromorphic theory, and the generalized continuum field theory is discussed. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...] [article] A generalized continuum theory and Its relation to micromorphic theory [texte imprimé] / Youping Chen, Auteur ; James Lee, Auteur ; Liming Xiong, Auteur . - pp. 149-155. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 135 N°3 (Mars 2009) . - pp. 149-155 Mots-clés : Continuum  mechanics  Theories. Résumé : Classic continuum mechanics views a crystal as a homogeneous and continuous medium, in which the basic structural unit of the crystal is taken without structure and is idealized as point mass. Micromorphic theory views a material as a continuous collection of deformable point particles; each particle has finite size and additional nine internal degrees of freedom describing the stretches and rotations of the particle. This paper presents a multiscale field theory that views a crystalline material as a continuous collection of lattice points, while embedded within each point is a group of discrete atoms. The atomistic formulation of the field theory is briefly introduced. Its relation with the well-known micromorphic theory is derived. The applicability of the classical continuum theory, micromorphic theory, and the generalized continuum field theory is discussed. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...]

Multiscale computation for nano/micromaterials / James D. Lee in Journal of engineering mechanics, Vol. 135 N°3 (Mars 2009) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 135 N°3 (Mars 2009) . - pp. 192-202 Titre : Multiscale computation for nano/micromaterials Type de document : texte imprimé Auteurs : James D. Lee, Auteur ; Xianqiao Wang, Auteur ; Youping Chen, Auteur Article en page(s) : pp. 192-202 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Computation  Material  properties  Simulation. Résumé : This paper presents a multiscale field theory and its applications in modeling and simulation of atomistic systems. The theoretical construction of the multiscale field theory is briefly introduced. A single crystal is discretized into finite-element mesh as if it is a continuous medium. However, each node is a representative unit cell, which contains a specified number of distinctive atoms. Ordinary differential equations for each atom in all nodes are obtained. Material behaviors of a given atomistic system at nano/microscale, subject to the combination of mechanical loadings, electromagnetic field, and temperature field, can be obtained through numerical simulations. Sample problems on wave propagation and simple tension have been solved to demonstrate the advantage and applicability of this multiscale field theory. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...] [article] Multiscale computation for nano/micromaterials [texte imprimé] / James D. Lee, Auteur ; Xianqiao Wang, Auteur ; Youping Chen, Auteur . - pp. 192-202. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 135 N°3 (Mars 2009) . - pp. 192-202 Mots-clés : Computation  Material  properties  Simulation. Résumé : This paper presents a multiscale field theory and its applications in modeling and simulation of atomistic systems. The theoretical construction of the multiscale field theory is briefly introduced. A single crystal is discretized into finite-element mesh as if it is a continuous medium. However, each node is a representative unit cell, which contains a specified number of distinctive atoms. Ordinary differential equations for each atom in all nodes are obtained. Material behaviors of a given atomistic system at nano/microscale, subject to the combination of mechanical loadings, electromagnetic field, and temperature field, can be obtained through numerical simulations. Sample problems on wave propagation and simple tension have been solved to demonstrate the advantage and applicability of this multiscale field theory. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...]