Documents disponibles écrits par cet auteur

Finite-element model for pretensioned prestressed concrete girders / Ayoub, Ashraf in Journal of structural engineering, Vol. 136 N° 4 (Avril 2010) 

Public ISBD [article]  in Journal of structural engineering > Vol. 136 N° 4 (Avril 2010) . - pp. 401-409 Titre : Finite-element model for pretensioned prestressed concrete girders Type de document : texte imprimé Auteurs : Ayoub, Ashraf, Auteur ; Filip C. Filippou, Auteur Année de publication : 2010 Article en page(s) : pp. 401-409 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Prestressed  concrete  Pretensioning  Finite-element  method  Nonlinear  analysis  Bond  stress  Slip Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents a nonlinear model for pretensioned prestressed concrete girders. The model consists of three main components: a beam-column element that describes the behavior of concrete, a truss element that describes the behavior of prestressing tendons, and a bond element that describes the transfer of stresses between the prestressing tendons and the concrete. The model is based on a two-field mixed formulation, where forces and deformations are both approximated within the element. The nonlinear response of the concrete and tendon components is based on the section discretization into fibers with uniaxial hysteretic material models. The stress transfer mechanism is modeled with a distributed interface element with special bond stress-slip relation. A method for accurately simulating the prestressing operation is presented. Accordingly, a complete nonlinear analysis is performed at the different stages of prestressing. Correlation studies of the proposed model with experimental results of pretensioned specimens are conducted. These studies confirmed the accuracy and efficiency of the model. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i4/p401_s1?isAuthorized=no [article] Finite-element model for pretensioned prestressed concrete girders [texte imprimé] / Ayoub, Ashraf, Auteur ; Filip C. Filippou, Auteur . - 2010 . - pp. 401-409. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 136 N° 4 (Avril 2010) . - pp. 401-409 Mots-clés : Prestressed  concrete  Pretensioning  Finite-element  method  Nonlinear  analysis  Bond  stress  Slip Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents a nonlinear model for pretensioned prestressed concrete girders. The model consists of three main components: a beam-column element that describes the behavior of concrete, a truss element that describes the behavior of prestressing tendons, and a bond element that describes the transfer of stresses between the prestressing tendons and the concrete. The model is based on a two-field mixed formulation, where forces and deformations are both approximated within the element. The nonlinear response of the concrete and tendon components is based on the section discretization into fibers with uniaxial hysteretic material models. The stress transfer mechanism is modeled with a distributed interface element with special bond stress-slip relation. A method for accurately simulating the prestressing operation is presented. Accordingly, a complete nonlinear analysis is performed at the different stages of prestressing. Correlation studies of the proposed model with experimental results of pretensioned specimens are conducted. These studies confirmed the accuracy and efficiency of the model. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i4/p401_s1?isAuthorized=no

Section discretization of fiber beam-column elements for cyclic inelastic response / Svetlana M. Kostic in Journal of structural engineering, Vol. 138 N° 5 (Mai 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 5 (Mai 2012) . - pp.592–601. Titre : Section discretization of fiber beam-column elements for cyclic inelastic response Type de document : texte imprimé Auteurs : Svetlana M. Kostic, Auteur ; Filip C. Filippou, Auteur Année de publication : 2012 Article en page(s) : pp.592–601. Note générale : Génie civil Langues : Anglais (eng) Mots-clés : Beam  columns  Nonlinear  analysis  Inelasticity  Cross  sections Résumé : The paper presents studies of the effect of the number of material integration points at the monitored sections of fiber beam-column elements on the local response of typical structural cross sections under an extensive set of cyclic biaxial load conditions with constant and variable axial load. The study covers wide-flange steel sections and rectangular reinforced concrete sections. The integration over the section uses the midpoint rule and shows that a standard section discretization with relatively few fibers is a good compromise between accuracy and economy of means. The proposed coarse section discretization schemes are computationally efficient while ensuring the accurate representation of important aspects of the three-dimensional response of structural members, such as interaction of axial force with biaxial bending moment, effect of residual stress in steel members, and effect of cracking in reinforced concrete members. The local strain response is also represented with good accuracy by the coarse discretization schemes. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000501 [article] Section discretization of fiber beam-column elements for cyclic inelastic response [texte imprimé] / Svetlana M. Kostic, Auteur ; Filip C. Filippou, Auteur . - 2012 . - pp.592–601. Génie civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 5 (Mai 2012) . - pp.592–601. Mots-clés : Beam  columns  Nonlinear  analysis  Inelasticity  Cross  sections Résumé : The paper presents studies of the effect of the number of material integration points at the monitored sections of fiber beam-column elements on the local response of typical structural cross sections under an extensive set of cyclic biaxial load conditions with constant and variable axial load. The study covers wide-flange steel sections and rectangular reinforced concrete sections. The integration over the section uses the midpoint rule and shows that a standard section discretization with relatively few fibers is a good compromise between accuracy and economy of means. The proposed coarse section discretization schemes are computationally efficient while ensuring the accurate representation of important aspects of the three-dimensional response of structural members, such as interaction of axial force with biaxial bending moment, effect of residual stress in steel members, and effect of cracking in reinforced concrete members. The local strain response is also represented with good accuracy by the coarse discretization schemes. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000501