Documents disponibles écrits par cet auteur

Control of a seismically excited benchmark building using linear matrix inequality-based semiactive nonlinear fuzzy control / Yeesock Kim in Journal of structural engineering, Vol. 136 N° 8 (Août 2010) 

Public ISBD [article]  in Journal of structural engineering > Vol. 136 N° 8 (Août 2010) . - pp. 1023-1026 Titre : Control of a seismically excited benchmark building using linear matrix inequality-based semiactive nonlinear fuzzy control Type de document : texte imprimé Auteurs : Yeesock Kim, Auteur ; Reza Langari, Auteur ; Hurlebaus, Stefan, Auteur Année de publication : 2011 Article en page(s) : pp. 1023-1026 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Semiactive  nonlinear  fuzzy  control  (SNFC)  Linear  matrix  inequalities  (LMIs)  Magnetorheological  (MR)  damper  Benchmark  Earthquake  Model-based  Fuzzy  logic  controller  (MBFLC)  Model-free  fuzzy  logic  controller  (MFFLC)  Vibration Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper investigates the behavior of a seismically excited benchmark building employing magnetorheological dampers operated by a model-based fuzzy logic controller (MBFLC) formulated in terms of linear matrix inequalities (LMIs). The MBFLC is designed in a systematic way, while the traditional model-free fuzzy logic controller is designed via trial and error by experienced investigators. It is demonstrated from comparison of the uncontrolled and semiactive controlled responses that the proposed LMI-based MBFLC is effective in vibration reduction of a benchmark building under various earthquake loading conditions. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i8/p1023_s1?isAuthorized=no [article] Control of a seismically excited benchmark building using linear matrix inequality-based semiactive nonlinear fuzzy control [texte imprimé] / Yeesock Kim, Auteur ; Reza Langari, Auteur ; Hurlebaus, Stefan, Auteur . - 2011 . - pp. 1023-1026. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 136 N° 8 (Août 2010) . - pp. 1023-1026 Mots-clés : Semiactive  nonlinear  fuzzy  control  (SNFC)  Linear  matrix  inequalities  (LMIs)  Magnetorheological  (MR)  damper  Benchmark  Earthquake  Model-based  Fuzzy  logic  controller  (MBFLC)  Model-free  fuzzy  logic  controller  (MFFLC)  Vibration Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper investigates the behavior of a seismically excited benchmark building employing magnetorheological dampers operated by a model-based fuzzy logic controller (MBFLC) formulated in terms of linear matrix inequalities (LMIs). The MBFLC is designed in a systematic way, while the traditional model-free fuzzy logic controller is designed via trial and error by experienced investigators. It is demonstrated from comparison of the uncontrolled and semiactive controlled responses that the proposed LMI-based MBFLC is effective in vibration reduction of a benchmark building under various earthquake loading conditions. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i8/p1023_s1?isAuthorized=no

Probabilistic capacity models and fragility estimates for reinforced concrete columns incorporating NDT data / Huang, Qindan in Journal of engineering mechanics, Vol. 135 N° 12 (Décembre 2009) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 135 N° 12 (Décembre 2009) . - pp. 1384-1392 Titre : Probabilistic capacity models and fragility estimates for reinforced concrete columns incorporating NDT data Type de document : texte imprimé Auteurs : Huang, Qindan, Auteur ; Gardoni, Paolo, Auteur ; Hurlebaus, Stefan, Auteur Article en page(s) : pp. 1384-1392 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Bridges  Probability  Nondestructive  tests  Concrete  columns  Reinforced  concrete. Résumé : Knowing the ability of reinforced concrete (RC) bridges to withstand future seismic demands during their life-cycle can help bridge owners make rational decisions regarding optimal allocation of resources for maintenance, repair, and/or rehabilitation of bridge systems. The accuracy of a reliability assessment can be improved by incorporating information about the current aging and deterioration conditions of a bridge. Nondestructive testing (NDT) can be used to evaluate the actual conditions of a bridge, avoiding the use of deterioration models that bring additional uncertainties in the reliability assessment. This paper develops probabilistic deformation and shear capacity models for RC bridge columns that incorporate information obtained from NDT. The proposed models can be used when the flexural stiffness decays nonuniformly over a column height. The flexural stiffness of a column is estimated based on measured acceleration responses using a system identification method and the damage index method. As an application of the proposed models, a case study assesses the fragility (the conditional probability of attaining or exceeding a specified capacity level) of the column in the Lavic Road Overcrossing for a given deformation or shear demand. This two-span concrete box-girder bridge located in Southern California was subject to the Hector Mine Earthquake in 1999. Pre- and postearthquake estimates of the univariate shear and deformation fragilities and of the bivariate shear-deformation fragility are computed and compared. Both displacement and shear capacities are found to decrease after the earthquake event. Additionally, the results show that the damage due to the Hector Mine Earthquake has a larger impact on the shear capacity than the deformation capacity, leading to a more significant increment in the shear fragility than in the deformation fragility. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JENMDT&smode=strres [...] [article] Probabilistic capacity models and fragility estimates for reinforced concrete columns incorporating NDT data [texte imprimé] / Huang, Qindan, Auteur ; Gardoni, Paolo, Auteur ; Hurlebaus, Stefan, Auteur . - pp. 1384-1392. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 135 N° 12 (Décembre 2009) . - pp. 1384-1392 Mots-clés : Bridges  Probability  Nondestructive  tests  Concrete  columns  Reinforced  concrete. Résumé : Knowing the ability of reinforced concrete (RC) bridges to withstand future seismic demands during their life-cycle can help bridge owners make rational decisions regarding optimal allocation of resources for maintenance, repair, and/or rehabilitation of bridge systems. The accuracy of a reliability assessment can be improved by incorporating information about the current aging and deterioration conditions of a bridge. Nondestructive testing (NDT) can be used to evaluate the actual conditions of a bridge, avoiding the use of deterioration models that bring additional uncertainties in the reliability assessment. This paper develops probabilistic deformation and shear capacity models for RC bridge columns that incorporate information obtained from NDT. The proposed models can be used when the flexural stiffness decays nonuniformly over a column height. The flexural stiffness of a column is estimated based on measured acceleration responses using a system identification method and the damage index method. As an application of the proposed models, a case study assesses the fragility (the conditional probability of attaining or exceeding a specified capacity level) of the column in the Lavic Road Overcrossing for a given deformation or shear demand. This two-span concrete box-girder bridge located in Southern California was subject to the Hector Mine Earthquake in 1999. Pre- and postearthquake estimates of the univariate shear and deformation fragilities and of the bivariate shear-deformation fragility are computed and compared. Both displacement and shear capacities are found to decrease after the earthquake event. Additionally, the results show that the damage due to the Hector Mine Earthquake has a larger impact on the shear capacity than the deformation capacity, leading to a more significant increment in the shear fragility than in the deformation fragility. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JENMDT&smode=strres [...]

Tension stiffening in prestressed concrete beams using moment-curvature relationship / Shobeir Pirayeh Gar in Journal of structural engineering, Vol. 138 N° 8 (Août 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 8 (Août 2012) . - pp.1075–1078. Titre : Tension stiffening in prestressed concrete beams using moment-curvature relationship Type de document : texte imprimé Auteurs : Shobeir Pirayeh Gar, Auteur ; Hurlebaus, Stefan, Auteur Année de publication : 2012 Article en page(s) : pp.1075–1078. Note générale : Génie civil Langues : Anglais (eng) Mots-clés : Tension  stiffening  Moment-curvature  Prestressing  Cracking  Serviceability  Concrete  beams Résumé : Tension stiffening phenomenon plays a vital role in serviceability of nonprestressed reinforced concrete (RC) beams as it enhances the postcracking flexural stiffness leading to a smaller deflection, accordingly. However, this paper’s findings indicate that in contrast to RC sections, the effect of tension stiffening is negligible for fully prestressed concrete sections. This study presents a closed form equation of moment-curvature for prestressed concrete sections under service load, where the tensile strength of the concrete is taken into account. This equation is verified by experimental test data and numerical analysis, thereby proving the negligible effect of tension stiffening on fully prestressed concrete sections. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000534 [article] Tension stiffening in prestressed concrete beams using moment-curvature relationship [texte imprimé] / Shobeir Pirayeh Gar, Auteur ; Hurlebaus, Stefan, Auteur . - 2012 . - pp.1075–1078. Génie civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 8 (Août 2012) . - pp.1075–1078. Mots-clés : Tension  stiffening  Moment-curvature  Prestressing  Cracking  Serviceability  Concrete  beams Résumé : Tension stiffening phenomenon plays a vital role in serviceability of nonprestressed reinforced concrete (RC) beams as it enhances the postcracking flexural stiffness leading to a smaller deflection, accordingly. However, this paper’s findings indicate that in contrast to RC sections, the effect of tension stiffening is negligible for fully prestressed concrete sections. This study presents a closed form equation of moment-curvature for prestressed concrete sections under service load, where the tensile strength of the concrete is taken into account. This equation is verified by experimental test data and numerical analysis, thereby proving the negligible effect of tension stiffening on fully prestressed concrete sections. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000534