Documents disponibles écrits par cet auteur

Evaluation of the sand-cone method for determination of the in-situ density of soil / S.-S. Park in Géotechnique, Vol. 60 N° 9 (Septembre 2010) 

Public ISBD [article]  in Géotechnique > Vol. 60 N° 9 (Septembre 2010) . - pp. 701–707 Titre : Evaluation of the sand-cone method for determination of the in-situ density of soil Type de document : texte imprimé Auteurs : S.-S. Park, Auteur Année de publication : 2011 Article en page(s) : pp. 701–707 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Standards  Compaction  Sands Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : A sand-cone method is commonly used to determine the density of compacted soils. The density of the compacted soil calculated from the sand-cone method could be correct, provided the calibration container has approximately the same size or volume and allows the sand to fall to approximately the same height as a test hole in the field. However, in most cases, the size or shape of the test hole is not exactly the same as that of the calibration container. This can result in a difference in the settlement or deposition of sand particles between the laboratory calibration and the field testing, which may cause an erroneous determination of the in-situ density. The sand-filling process is simulated in the laboratory and its effect on the determination of density is investigated. Artificially made holes with different depths and bottom shapes are prepared to simulate various shapes of the test hole in the field. Sands with different particle size distributions are used in the testing to examine how sand grain size influences the determination of density in the field. The error between the assumed and calculated densities is highly dependent on the types of sand used in the sand-cone method. This paper presents some guidelines for obtaining correct in-situ densities through the sand-cone method. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.9.t.004 [article] Evaluation of the sand-cone method for determination of the in-situ density of soil [texte imprimé] / S.-S. Park, Auteur . - 2011 . - pp. 701–707. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 60 N° 9 (Septembre 2010) . - pp. 701–707 Mots-clés : Standards  Compaction  Sands Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : A sand-cone method is commonly used to determine the density of compacted soils. The density of the compacted soil calculated from the sand-cone method could be correct, provided the calibration container has approximately the same size or volume and allows the sand to fall to approximately the same height as a test hole in the field. However, in most cases, the size or shape of the test hole is not exactly the same as that of the calibration container. This can result in a difference in the settlement or deposition of sand particles between the laboratory calibration and the field testing, which may cause an erroneous determination of the in-situ density. The sand-filling process is simulated in the laboratory and its effect on the determination of density is investigated. Artificially made holes with different depths and bottom shapes are prepared to simulate various shapes of the test hole in the field. Sands with different particle size distributions are used in the testing to examine how sand grain size influences the determination of density in the field. The error between the assumed and calculated densities is highly dependent on the types of sand used in the sand-cone method. This paper presents some guidelines for obtaining correct in-situ densities through the sand-cone method. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.9.t.004

Simulation of stress concentration in Mg alloys using the crystal plasticity finite element method / S.-H. Choi in Acta materialia, Vol. 58 N° 1 (Janvier 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 1 (Janvier 2010) . - pp. 320–329 Titre : Simulation of stress concentration in Mg alloys using the crystal plasticity finite element method Type de document : texte imprimé Auteurs : S.-H. Choi, Auteur ; D.H. Kim, Auteur ; S.-S. Park, Auteur Année de publication : 2010 Article en page(s) : pp. 320–329 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Crystal  plasticity  Finite  element  Stress  concentration  Texture  Twinning Résumé : A crystal plasticity finite element method (CPFEM), considering both crystallographic slip and deformation twinning, was developed to simulate the spatial stress concentration in AZ31 Mg alloys during in-plane compression. A predominant twin reorientation (PTR) model was successfully implemented to capture grain reorientation due to deformation twinning in twin-dominated deformation. By using the direct mapping technique for electron backscatter diffraction (EBSD) data, CPFEM can capture the heterogeneity of stress concentration at the grain boundaries in AZ31 Mg alloys during in-plane compression. The model demonstrated that deformation twinning enhances the local stress concentration at the grain boundaries between untwinned and twinned grains. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409006065 [article] Simulation of stress concentration in Mg alloys using the crystal plasticity finite element method [texte imprimé] / S.-H. Choi, Auteur ; D.H. Kim, Auteur ; S.-S. Park, Auteur . - 2010 . - pp. 320–329. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 1 (Janvier 2010) . - pp. 320–329 Mots-clés : Crystal  plasticity  Finite  element  Stress  concentration  Texture  Twinning Résumé : A crystal plasticity finite element method (CPFEM), considering both crystallographic slip and deformation twinning, was developed to simulate the spatial stress concentration in AZ31 Mg alloys during in-plane compression. A predominant twin reorientation (PTR) model was successfully implemented to capture grain reorientation due to deformation twinning in twin-dominated deformation. By using the direct mapping technique for electron backscatter diffraction (EBSD) data, CPFEM can capture the heterogeneity of stress concentration at the grain boundaries in AZ31 Mg alloys during in-plane compression. The model demonstrated that deformation twinning enhances the local stress concentration at the grain boundaries between untwinned and twinned grains. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409006065