Documents disponibles écrits par cet auteur

Nonlinear finite-element analysis of critical gusset plates in the I-35W bridge in Minnesota / Minmao Liao in Journal of structural engineering, Vol. 137 N° 1 (Janvier 2011) 

Public ISBD [article]  in Journal of structural engineering > Vol. 137 N° 1 (Janvier 2011) . - pp. 59-68 Titre : Nonlinear finite-element analysis of critical gusset plates in the I-35W bridge in Minnesota Type de document : texte imprimé Auteurs : Minmao Liao, Auteur ; Taichiro Okazaki, Auteur ; Roberto Ballarini, Auteur Année de publication : 2011 Article en page(s) : pp. 59-68 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Connections  Finite-element  method  Nonlinear  analysis  Bridge  failure Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Reported evidence suggests that failure of gusset plates initiated the collapse of the I-35W Bridge in Minneapolis, Minnesota. The particular gusset plates were at a panel point designated as U10. Therefore, an analytical investigation was conducted on the condition of the U10 gusset plates at the time of bridge collapse. The forces delivered to panel point U10 were reproduced using available information of the bridge. These forces were introduced to detailed nonlinear three-dimensional finite-element models to calculate stress and strain states of the gusset plates. The results indicate that substantial portions of the U10 gusset plates were yielded at the time of collapse, confirming earlier findings from federal and state investigations. Weight increase due to past deck reconstruction and construction material and equipment staged on the day of collapse, along with insufficient thickness of the gusset plate, were identified as the main contributing factors to the substantial yielding. The results also suggest that the interaction of compression and shear played an important role in the gusset plate failure. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i1/p59_s1?isAuthorized=no [article] Nonlinear finite-element analysis of critical gusset plates in the I-35W bridge in Minnesota [texte imprimé] / Minmao Liao, Auteur ; Taichiro Okazaki, Auteur ; Roberto Ballarini, Auteur . - 2011 . - pp. 59-68. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 137 N° 1 (Janvier 2011) . - pp. 59-68 Mots-clés : Connections  Finite-element  method  Nonlinear  analysis  Bridge  failure Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Reported evidence suggests that failure of gusset plates initiated the collapse of the I-35W Bridge in Minneapolis, Minnesota. The particular gusset plates were at a panel point designated as U10. Therefore, an analytical investigation was conducted on the condition of the U10 gusset plates at the time of bridge collapse. The forces delivered to panel point U10 were reproduced using available information of the bridge. These forces were introduced to detailed nonlinear three-dimensional finite-element models to calculate stress and strain states of the gusset plates. The results indicate that substantial portions of the U10 gusset plates were yielded at the time of collapse, confirming earlier findings from federal and state investigations. Weight increase due to past deck reconstruction and construction material and equipment staged on the day of collapse, along with insufficient thickness of the gusset plate, were identified as the main contributing factors to the substantial yielding. The results also suggest that the interaction of compression and shear played an important role in the gusset plate failure. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i1/p59_s1?isAuthorized=no

Toward a fracture mechanics – based design approach for unbonded concrete overlay pavements / Minmao Liao in Journal of engineering mechanics, Vol. 138 N° 9 (Septembre 2012) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 138 N° 9 (Septembre 2012) . - pp.1195–1204. Titre : Toward a fracture mechanics – based design approach for unbonded concrete overlay pavements Type de document : texte imprimé Auteurs : Minmao Liao, Auteur ; Roberto Ballarini, Auteur Année de publication : 2012 Article en page(s) : pp.1195–1204. Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Pavement  overlays  Composite  structures  Cracking  Finite-element  method  Equivalence Résumé : An illustrative fracture mechanics–based design paradigm is proposed for unbonded concrete overlays (UBCOs), an increasingly popular pavement rehabilitation system, with the ultimate goal of establishing a more rational design procedure than those currently available. To illustrate the advantages of the fracture mechanics–based approach to design, specific attention is paid to one type of failure associated with pavement structures, reflection cracking. The design formulas derived from the results of a large number of crack propagation simulations of both the UBCO composite and a reference single-layer new pavement quantify the dependence of the required overlay thickness and load-carrying capacity on all relevant material and geometric parameters. Preliminary comparisons of the results with field observations suggest that the fracture mechanics paradigm offers a promising procedure for improved design of UBCOs. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000412 [article] Toward a fracture mechanics – based design approach for unbonded concrete overlay pavements [texte imprimé] / Minmao Liao, Auteur ; Roberto Ballarini, Auteur . - 2012 . - pp.1195–1204. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 138 N° 9 (Septembre 2012) . - pp.1195–1204. Mots-clés : Pavement  overlays  Composite  structures  Cracking  Finite-element  method  Equivalence Résumé : An illustrative fracture mechanics–based design paradigm is proposed for unbonded concrete overlays (UBCOs), an increasingly popular pavement rehabilitation system, with the ultimate goal of establishing a more rational design procedure than those currently available. To illustrate the advantages of the fracture mechanics–based approach to design, specific attention is paid to one type of failure associated with pavement structures, reflection cracking. The design formulas derived from the results of a large number of crack propagation simulations of both the UBCO composite and a reference single-layer new pavement quantify the dependence of the required overlay thickness and load-carrying capacity on all relevant material and geometric parameters. Preliminary comparisons of the results with field observations suggest that the fracture mechanics paradigm offers a promising procedure for improved design of UBCOs. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000412