Documents disponibles écrits par cet auteur

Effect of cumulative seismic damage and corrosion on the life-cycle cost of reinforced concrete bridges / R. Kumar in Earthquake engineering structural dynamics, Vol. 38 N° 7 (Juin 2009) 

Public ISBD [article]  in Earthquake engineering structural dynamics > Vol. 38 N° 7 (Juin 2009) . - pp. 887-905 Titre : Effect of cumulative seismic damage and corrosion on the life-cycle cost of reinforced concrete bridges Type de document : texte imprimé Auteurs : R. Kumar, Auteur ; P. Gardoni, Auteur ; M. Sanchez-Silva, Auteur Article en page(s) : pp. 887-905 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Life-cycle  cost;  Cumulative  seismic  damage;  Low-cycle  fatigue  ;  Reinforced  concrete  bridges;  Monte-Carlo  simulation;  Corrosion Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Bridge design should take into account not only safety and functionality, but also the cost effectiveness of investments throughout a bridge life-cycle. This paper presents a probabilistic approach to compute the life-cycle cost (LCC) of corroding reinforced concrete (RC) bridges in earthquake-prone regions. The approach is developed by combining cumulative seismic damage and damage associated with corrosion due to environmental conditions. Cumulative seismic damage is obtained from a low-cycle fatigue analysis. Chloride-induced corrosion of steel reinforcement is computed based on Fick's second law of diffusion. The proposed methodology accounts for the uncertainties in the ground motion parameters, the distance from the source, the seismic demand on the bridge, and the corrosion initiation time. The statistics of the accumulated damage and the cost of repairs throughout the bridge life-cycle are obtained by Monte-Carlo simulation. As an illustration of the proposed approach, the effects of design parameters on the LCC of an example RC bridge are studied. The results are valuable in better estimating the condition of existing bridges and, therefore, can help to schedule inspection and maintenance programs. In addition, by taking into consideration the two deterioration processes over a bridge life-cycle, it is possible to estimate the optimal design parameters by minimizing, for example, the expected cost throughout the life of the structure. A comparison between the effects of the two deterioration processes shows that, in seismic regions, the cumulative seismic damage affects the reliability of bridges over time more than the corrosion even for corrosive environments. ISSN : 0098-8847 En ligne : http://www3.interscience.wiley.com/journal/121520102/abstract [article] Effect of cumulative seismic damage and corrosion on the life-cycle cost of reinforced concrete bridges [texte imprimé] / R. Kumar, Auteur ; P. Gardoni, Auteur ; M. Sanchez-Silva, Auteur . - pp. 887-905. Génie Civil Langues : Anglais (eng) in Earthquake engineering structural dynamics > Vol. 38 N° 7 (Juin 2009) . - pp. 887-905 Mots-clés : Life-cycle  cost;  Cumulative  seismic  damage;  Low-cycle  fatigue  ;  Reinforced  concrete  bridges;  Monte-Carlo  simulation;  Corrosion Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Bridge design should take into account not only safety and functionality, but also the cost effectiveness of investments throughout a bridge life-cycle. This paper presents a probabilistic approach to compute the life-cycle cost (LCC) of corroding reinforced concrete (RC) bridges in earthquake-prone regions. The approach is developed by combining cumulative seismic damage and damage associated with corrosion due to environmental conditions. Cumulative seismic damage is obtained from a low-cycle fatigue analysis. Chloride-induced corrosion of steel reinforcement is computed based on Fick's second law of diffusion. The proposed methodology accounts for the uncertainties in the ground motion parameters, the distance from the source, the seismic demand on the bridge, and the corrosion initiation time. The statistics of the accumulated damage and the cost of repairs throughout the bridge life-cycle are obtained by Monte-Carlo simulation. As an illustration of the proposed approach, the effects of design parameters on the LCC of an example RC bridge are studied. The results are valuable in better estimating the condition of existing bridges and, therefore, can help to schedule inspection and maintenance programs. In addition, by taking into consideration the two deterioration processes over a bridge life-cycle, it is possible to estimate the optimal design parameters by minimizing, for example, the expected cost throughout the life of the structure. A comparison between the effects of the two deterioration processes shows that, in seismic regions, the cumulative seismic damage affects the reliability of bridges over time more than the corrosion even for corrosive environments. ISSN : 0098-8847 En ligne : http://www3.interscience.wiley.com/journal/121520102/abstract

Model uncertainty in finite-element analysis / T. Haukaas in Journal of engineering mechanics, Vol. 137 N° 8 (Août 2011) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 137 N° 8 (Août 2011) . - pp.519-526 Titre : Model uncertainty in finite-element analysis : bayesian finite elements Type de document : texte imprimé Auteurs : T. Haukaas, Auteur ; P. Gardoni, Auteur Année de publication : 2011 Article en page(s) : pp.519-526 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Probabilistic  models  Model  uncertainty  Finite  elements  Bayesian  updating Résumé : In this paper, probabilistic models for structural analysis are put forward, with particular emphasis on model uncertainty. Context is provided by the finite-element method and the need for probabilistic prediction of structural performance in contemporary engineering. Sources of model uncertainty are identified and modeled. A Bayesian approach is suggested for the assessment of new model parameters within the element formulations. The expressions are formulated by means of numerical “sensors” that influence the model uncertainty, such as element distortion and degree of nonlinearity. An assessment procedure is proposed to identify the sensors that are most suitable to capture model uncertainty. This paper presents the general methodology and specific implementations for a general-purpose structural element. Two numerical examples are presented to demonstrate the methodology and its implications for probabilistic prediction of structural response. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i8/p519_s1?isAuthorized=no [article] Model uncertainty in finite-element analysis : bayesian finite elements [texte imprimé] / T. Haukaas, Auteur ; P. Gardoni, Auteur . - 2011 . - pp.519-526. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 137 N° 8 (Août 2011) . - pp.519-526 Mots-clés : Probabilistic  models  Model  uncertainty  Finite  elements  Bayesian  updating Résumé : In this paper, probabilistic models for structural analysis are put forward, with particular emphasis on model uncertainty. Context is provided by the finite-element method and the need for probabilistic prediction of structural performance in contemporary engineering. Sources of model uncertainty are identified and modeled. A Bayesian approach is suggested for the assessment of new model parameters within the element formulations. The expressions are formulated by means of numerical “sensors” that influence the model uncertainty, such as element distortion and degree of nonlinearity. An assessment procedure is proposed to identify the sensors that are most suitable to capture model uncertainty. This paper presents the general methodology and specific implementations for a general-purpose structural element. Two numerical examples are presented to demonstrate the methodology and its implications for probabilistic prediction of structural response. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i8/p519_s1?isAuthorized=no