Documents disponibles écrits par cet auteur

Effects of alloying elements, microstructure, and inclusions on hydrogen induced cracking of X120 pipeline steel in wet H2S sour environment / F. Huang in Materials and corrosion, Vol. 63 N° 1 (Janvier 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 1 (Janvier 2012) . - pp. 59–66 Titre : Effects of alloying elements, microstructure, and inclusions on hydrogen induced cracking of X120 pipeline steel in wet H2S sour environment Type de document : texte imprimé Auteurs : F. Huang, Auteur ; X. G. Li, Auteur ; J. Liu, Auteur Année de publication : 2012 Article en page(s) : pp. 59–66 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Hydrogen  induced  cracking  Inclusions  Pipeline  steel  Scanning  electron  microscopy Résumé : Hydrogen induced cracking (HIC) behavior of X120 pipeline steel with different amounts of Mn and Al was investigated using NACE standard TM0284-2005 and back-scattered electron imaging (BSE). The results demonstrated that inclusions and microstructure play significant roles in HIC susceptibility in X120 steels. The more the area and volume fraction of inclusions in the steel, the more the steel is susceptible to HIC. Three types of inclusions exist in the tested X120 steel and they play different roles in cracking. The critical size resulting in HIC cracks for pure MnS inclusions or mixed inclusions (inclusion clusters mainly composed of two or three different phases and compounds) of Mn/Al ratio >1 is smaller than that of pure Al2O3 inclusions or mixed inclusions of Mn/Al ratio <1. No HIC crack was observed at inclusions enriched in Si. The microstructure containing lath bainite and martensite/austenite (M/A) microconstituents is more susceptible to HIC than that with granular bainite and ferrite. DEWEY : 620.1 ISSN : 0947-5114 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005649/abstract [article] Effects of alloying elements, microstructure, and inclusions on hydrogen induced cracking of X120 pipeline steel in wet H2S sour environment [texte imprimé] / F. Huang, Auteur ; X. G. Li, Auteur ; J. Liu, Auteur . - 2012 . - pp. 59–66. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 1 (Janvier 2012) . - pp. 59–66 Mots-clés : Hydrogen  induced  cracking  Inclusions  Pipeline  steel  Scanning  electron  microscopy Résumé : Hydrogen induced cracking (HIC) behavior of X120 pipeline steel with different amounts of Mn and Al was investigated using NACE standard TM0284-2005 and back-scattered electron imaging (BSE). The results demonstrated that inclusions and microstructure play significant roles in HIC susceptibility in X120 steels. The more the area and volume fraction of inclusions in the steel, the more the steel is susceptible to HIC. Three types of inclusions exist in the tested X120 steel and they play different roles in cracking. The critical size resulting in HIC cracks for pure MnS inclusions or mixed inclusions (inclusion clusters mainly composed of two or three different phases and compounds) of Mn/Al ratio >1 is smaller than that of pure Al2O3 inclusions or mixed inclusions of Mn/Al ratio <1. No HIC crack was observed at inclusions enriched in Si. The microstructure containing lath bainite and martensite/austenite (M/A) microconstituents is more susceptible to HIC than that with granular bainite and ferrite. DEWEY : 620.1 ISSN : 0947-5114 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005649/abstract

Fillet weld groups loaded with out-of-plane eccentricity / A. M. Kanvinde in Journal of structural engineering, Vol. 139 N° 3 (Mars 2013) 

Public ISBD [article]  in Journal of structural engineering > Vol. 139 N° 3 (Mars 2013) . - pp. 305–319 Titre : Fillet weld groups loaded with out-of-plane eccentricity : simulations and new model for strength characterization Type de document : texte imprimé Auteurs : A. M. Kanvinde, Auteur ; J. Liu, Auteur ; X. Fu, Auteur Année de publication : 2013 Article en page(s) : pp. 305–319 Note générale : structural engineering Langues : Anglais (eng) Mots-clés : welding;  welded  connections;  finite  element  method;  simulation Résumé : The strength of fillet weld groups, loaded with an out-of-plane eccentricity, is controlled by complex interactions of weld yielding, as well as bearing between the connected parts. Current models that characterize connection strength, including those used in North American design specifications, are highly conservative, leading to oversized welds. These models are phenomenological, because the internal stress distribution within the welds is difficult to characterize experimentally. A new model is proposed for characterizing the strength of these connections. The model is based on insights developed from sophisticated finite-element (FE) simulations that feature accurate measurements of weld profiles, multiaxial plasticity, and simulation of contact and gapping phenomena that strongly influence connection response. The FE simulations reveal that current models do not reflect key aspects of force transfer within the connection, especially on the compression side. The proposed model incorporates these insights by using stress profiles and mechanisms consistent with those implied by the FE simulations. The model is evaluated against 79 experiments from three test programs. It is determined that the new model greatly reduces the conservatism of the existing models, resulting in an average test-to-predicted ratio of 1.01. This is in contrast to previous models, for which the average test-to-predicted ratios are in the range of 1.33–1.77. The efficacy of the proposed model is analyzed with respect to various parameters, and its limitations are outlined. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000641 [article] Fillet weld groups loaded with out-of-plane eccentricity : simulations and new model for strength characterization [texte imprimé] / A. M. Kanvinde, Auteur ; J. Liu, Auteur ; X. Fu, Auteur . - 2013 . - pp. 305–319. structural engineering Langues : Anglais (eng) in Journal of structural engineering > Vol. 139 N° 3 (Mars 2013) . - pp. 305–319 Mots-clés : welding;  welded  connections;  finite  element  method;  simulation Résumé : The strength of fillet weld groups, loaded with an out-of-plane eccentricity, is controlled by complex interactions of weld yielding, as well as bearing between the connected parts. Current models that characterize connection strength, including those used in North American design specifications, are highly conservative, leading to oversized welds. These models are phenomenological, because the internal stress distribution within the welds is difficult to characterize experimentally. A new model is proposed for characterizing the strength of these connections. The model is based on insights developed from sophisticated finite-element (FE) simulations that feature accurate measurements of weld profiles, multiaxial plasticity, and simulation of contact and gapping phenomena that strongly influence connection response. The FE simulations reveal that current models do not reflect key aspects of force transfer within the connection, especially on the compression side. The proposed model incorporates these insights by using stress profiles and mechanisms consistent with those implied by the FE simulations. The model is evaluated against 79 experiments from three test programs. It is determined that the new model greatly reduces the conservatism of the existing models, resulting in an average test-to-predicted ratio of 1.01. This is in contrast to previous models, for which the average test-to-predicted ratios are in the range of 1.33–1.77. The efficacy of the proposed model is analyzed with respect to various parameters, and its limitations are outlined. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000641

Load transfer behaviour of a tapered rigid pile / J. Liu in Géotechnique, Vol. 62 N° 7 (Juillet 2012) 

Public ISBD [article]  in Géotechnique > Vol. 62 N° 7 (Juillet 2012) . - pp. 649 –652 Titre : Load transfer behaviour of a tapered rigid pile Type de document : texte imprimé Auteurs : J. Liu, Auteur ; J. He, Auteur ; Y.-P. Wu, Auteur Année de publication : 2012 Article en page(s) : pp. 649 –652 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Numerical  modelling  Settlement  Piles  Bearing  capacity  Model  tests Résumé : Based on Mohr–Coulomb theory and the load transfer method, a new method of analysing the load–settlement relation and the axial force distribution model in a tapered pile is suggested. The method proposed in the paper considers the influence of the pile–soil radial interaction on the bearing capacity and settlement behaviour. The calculation results show that the pile–soil radial interaction is strengthened and the bearing capacity of a single pile is increased when the taper angle of a rigid pile is increased. The reliability was verified by two model tests. Calculated results obtained by the proposed method were compared with the test data. The close agreement between the calculated and measured values confirmed that the method is reasonably accurate for analysing the behaviour of tapered rigid piles. ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.11.T.001 [article] Load transfer behaviour of a tapered rigid pile [texte imprimé] / J. Liu, Auteur ; J. He, Auteur ; Y.-P. Wu, Auteur . - 2012 . - pp. 649 –652. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 62 N° 7 (Juillet 2012) . - pp. 649 –652 Mots-clés : Numerical  modelling  Settlement  Piles  Bearing  capacity  Model  tests Résumé : Based on Mohr–Coulomb theory and the load transfer method, a new method of analysing the load–settlement relation and the axial force distribution model in a tapered pile is suggested. The method proposed in the paper considers the influence of the pile–soil radial interaction on the bearing capacity and settlement behaviour. The calculation results show that the pile–soil radial interaction is strengthened and the bearing capacity of a single pile is increased when the taper angle of a rigid pile is increased. The reliability was verified by two model tests. Calculated results obtained by the proposed method were compared with the test data. The close agreement between the calculated and measured values confirmed that the method is reasonably accurate for analysing the behaviour of tapered rigid piles. ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.11.T.001

Numerical study on plate anchor stability in clay / L. Yu in Géotechnique, Vol. 61 N° 3 (Mars 2011) 

Public ISBD [article]  in Géotechnique > Vol. 61 N° 3 (Mars 2011) . - pp. 235–246 Titre : Numerical study on plate anchor stability in clay Type de document : texte imprimé Auteurs : L. Yu, Auteur ; J. Liu, Auteur ; X.-J. Kong, Auteur Année de publication : 2011 Article en page(s) : pp. 235–246 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Clays  Offshore  engineering  Bearing  capacity  Anchors Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Although the pullout capacity of plate anchors in clay has been studied extensively, the results considering the coupling effects of anchor inclination, clay non-homogeneity and self-weight are relatively rare. In the present paper, finite-element analyses are carried out to investigate the coupling effects of these factors on the pullout capacity of strip plate anchors in clay. The numerical solutions are presented in the familiar form of pullout capacity factors based on various anchor embedment depth, clay strength profile and clay self weight, and are also compared with existing numerical and empirical solutions. A design procedure based on the data-fitting equations of the present finite-element solutions is also presented for the convenience of design engineers. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.p.071 [article] Numerical study on plate anchor stability in clay [texte imprimé] / L. Yu, Auteur ; J. Liu, Auteur ; X.-J. Kong, Auteur . - 2011 . - pp. 235–246. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 61 N° 3 (Mars 2011) . - pp. 235–246 Mots-clés : Clays  Offshore  engineering  Bearing  capacity  Anchors Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Although the pullout capacity of plate anchors in clay has been studied extensively, the results considering the coupling effects of anchor inclination, clay non-homogeneity and self-weight are relatively rare. In the present paper, finite-element analyses are carried out to investigate the coupling effects of these factors on the pullout capacity of strip plate anchors in clay. The numerical solutions are presented in the familiar form of pullout capacity factors based on various anchor embedment depth, clay strength profile and clay self weight, and are also compared with existing numerical and empirical solutions. A design procedure based on the data-fitting equations of the present finite-element solutions is also presented for the convenience of design engineers. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.p.071

Study on corrosive electrochemical behaviors of zinc-rich and graphite-filled epoxy coatings in 3.5 wt% NaCl solution / J. Liu in Materials and corrosion, Vol. 62 N° 11 (Novembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 11 (Novembre 2011) . - pp.1008–1014 Titre : Study on corrosive electrochemical behaviors of zinc-rich and graphite-filled epoxy coatings in 3.5 wt% NaCl solution Type de document : texte imprimé Auteurs : J. Liu, Auteur ; F. Wang, Auteur ; K. C. Park, Auteur Année de publication : 2012 Article en page(s) : pp.1008–1014 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Corrosive  behaviors  EIS  Epoxy  coatings  Mechanisms  Seawater Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Environment behaviors and degradation mechanisms of two organic epoxy coatings coated on carbon steel sheets in 3.5 wt% NaCl neutral solution were studied by electrochemical impedance measurements and atomic force microscopy (AFM). The results showed that the coating resistance (Rp) of the graphite-filled epoxy coating tested, which presents the film barrier performance, is higher than those of 6101 epoxy resin for initial seawater immersion, but the coating resistance of the zinc-rich epoxy coating was lower than that of 6101 epoxy resin. After salt spray tests, zinc-rich epoxy coating coated on the metal still has good anti-corrosion performances due to the existence of protection effects called “electrochemical” and “chemical” protection. Those behaviors and degradation mechanisms of two coatings can be explained by a series of measured electrochemical impedance spectroscopy measurements, and two equivalent circuit models were proposed to explain the degradation processes of the two organic coatings. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905517/abstract [article] Study on corrosive electrochemical behaviors of zinc-rich and graphite-filled epoxy coatings in 3.5 wt% NaCl solution [texte imprimé] / J. Liu, Auteur ; F. Wang, Auteur ; K. C. Park, Auteur . - 2012 . - pp.1008–1014. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 11 (Novembre 2011) . - pp.1008–1014 Mots-clés : Corrosive  behaviors  EIS  Epoxy  coatings  Mechanisms  Seawater Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Environment behaviors and degradation mechanisms of two organic epoxy coatings coated on carbon steel sheets in 3.5 wt% NaCl neutral solution were studied by electrochemical impedance measurements and atomic force microscopy (AFM). The results showed that the coating resistance (Rp) of the graphite-filled epoxy coating tested, which presents the film barrier performance, is higher than those of 6101 epoxy resin for initial seawater immersion, but the coating resistance of the zinc-rich epoxy coating was lower than that of 6101 epoxy resin. After salt spray tests, zinc-rich epoxy coating coated on the metal still has good anti-corrosion performances due to the existence of protection effects called “electrochemical” and “chemical” protection. Those behaviors and degradation mechanisms of two coatings can be explained by a series of measured electrochemical impedance spectroscopy measurements, and two equivalent circuit models were proposed to explain the degradation processes of the two organic coatings. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905517/abstract