Documents disponibles écrits par cet auteur

Analysis of extensible reinforcement subject to oblique pull / J. T. Shahu in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N° 5 (Mai 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 5 (Mai 2009) . - pp. 623–634 Titre : Analysis of extensible reinforcement subject to oblique pull Type de document : texte imprimé Auteurs : J. T. Shahu, Auteur ; S. Hayashi, Auteur Année de publication : 2009 Article en page(s) : pp. 623–634 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Geosynthetics  Pull-out  resistance  Failure  Subgrades  Finite  element  method Résumé : A rational analysis of extensible sheet reinforcement subjected to an oblique end force has been presented that properly accounts for complex soil-reinforcement interaction and involves stress-deformation relationship implicitly. The results can be used for internal design of geosynthetic reinforced soil walls against pullout failure and tension failure. The pullout force and the end displacement at pullout for an extensible reinforcement are found to be almost the same as those for an inextensible reinforcement if the ratio of the reinforcement stiffness to the axial pullout capacity J∗ is greater than 15. With decrease in J∗ below 15, the maximum strain increases, the pullout failure becomes irrelevant, the tension failure dominates and the maximum allowable oblique force decreases. A minimum stiffness of about 25 times the axial pullout capacity is required to avoid the tension failure before the pullout provided the failure strain is 0.1. The predicted results have been calibrated against the finite-element analysis of pullout tests and detailed back analyses of published test data on model reinforced walls constructed with a wide range of extensible materials. The present analysis gives better predictions of the critical height against the pullout and the tension failure in model reinforced soil walls constructed with extensible reinforcements as compared to that of Rankine’s method. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000019 [article] Analysis of extensible reinforcement subject to oblique pull [texte imprimé] / J. T. Shahu, Auteur ; S. Hayashi, Auteur . - 2009 . - pp. 623–634. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 5 (Mai 2009) . - pp. 623–634 Mots-clés : Geosynthetics  Pull-out  resistance  Failure  Subgrades  Finite  element  method Résumé : A rational analysis of extensible sheet reinforcement subjected to an oblique end force has been presented that properly accounts for complex soil-reinforcement interaction and involves stress-deformation relationship implicitly. The results can be used for internal design of geosynthetic reinforced soil walls against pullout failure and tension failure. The pullout force and the end displacement at pullout for an extensible reinforcement are found to be almost the same as those for an inextensible reinforcement if the ratio of the reinforcement stiffness to the axial pullout capacity J∗ is greater than 15. With decrease in J∗ below 15, the maximum strain increases, the pullout failure becomes irrelevant, the tension failure dominates and the maximum allowable oblique force decreases. A minimum stiffness of about 25 times the axial pullout capacity is required to avoid the tension failure before the pullout provided the failure strain is 0.1. The predicted results have been calibrated against the finite-element analysis of pullout tests and detailed back analyses of published test data on model reinforced walls constructed with a wide range of extensible materials. The present analysis gives better predictions of the critical height against the pullout and the tension failure in model reinforced soil walls constructed with extensible reinforcements as compared to that of Rankine’s method. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000019

Effect of Fe and partial pressure of oxygen on the formation and phase transformation behavior of Al2O3 scale / S. Hayashi in Materials and corrosion, Vol. 63 N° 10 (Octobre 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 10 (Octobre 2012) . - pp. 862–868 Titre : Effect of Fe and partial pressure of oxygen on the formation and phase transformation behavior of Al2O3 scale Type de document : texte imprimé Auteurs : S. Hayashi, Auteur ; Y. Takada, Auteur ; I. Saeki, Auteur Année de publication : 2013 Article en page(s) : pp. 862–868 Note générale : Génie mécanique Langues : Anglais (eng) Résumé : The effect of oxygen partial pressure on the phase transformation of Al2O3 scale on various Fe–Al alloys with and without very thin (∼100 nm) Fe coating was investigated. Fe-coating on Fe–Al alloys can effectively suppress metastable Al2O3 formation, but little effect was observed when the samples were oxidized in a low partial pressure of oxygen. Under the low equation image atmosphere, metastable to stable α-Al2O3 scale phase transformation on both Fe-coated and non-coated Fe–Al alloys was significantly delayed. The lattice spacing of α-Al2O3 scale formed in air decreased with increasing alloy Al content. Further decrease in the lattice spacing of α-Al2O3 scale was observed when the alloy was oxidized in low equation image. The results obtained clearly indicated that the formation of Fe2O3 or Fe3+ in metastable Al2O3 accelerated the metastable to stable α-Al2O3 scale transformation. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201206731/abstract [article] Effect of Fe and partial pressure of oxygen on the formation and phase transformation behavior of Al2O3 scale [texte imprimé] / S. Hayashi, Auteur ; Y. Takada, Auteur ; I. Saeki, Auteur . - 2013 . - pp. 862–868. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 10 (Octobre 2012) . - pp. 862–868 Résumé : The effect of oxygen partial pressure on the phase transformation of Al2O3 scale on various Fe–Al alloys with and without very thin (∼100 nm) Fe coating was investigated. Fe-coating on Fe–Al alloys can effectively suppress metastable Al2O3 formation, but little effect was observed when the samples were oxidized in a low partial pressure of oxygen. Under the low equation image atmosphere, metastable to stable α-Al2O3 scale phase transformation on both Fe-coated and non-coated Fe–Al alloys was significantly delayed. The lattice spacing of α-Al2O3 scale formed in air decreased with increasing alloy Al content. Further decrease in the lattice spacing of α-Al2O3 scale was observed when the alloy was oxidized in low equation image. The results obtained clearly indicated that the formation of Fe2O3 or Fe3+ in metastable Al2O3 accelerated the metastable to stable α-Al2O3 scale transformation. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201206731/abstract