Documents disponibles écrits par cet auteur

Approximate boundaries for finite - element models of static soil – foundation interaction problems / Carlos M. Mozos in Journal of engineering mechanics, Vol. 137 N° 10 (Octobre 2011) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 137 N° 10 (Octobre 2011) . - pp.648-659 Titre : Approximate boundaries for finite - element models of static soil – foundation interaction problems Type de document : texte imprimé Auteurs : Carlos M. Mozos, Auteur ; J. Enrique Luco, Auteur Année de publication : 2012 Article en page(s) : pp.648-659 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Soil-structure  interactions  Soil-pile  interactions  Finite  element  method  Boundaries Résumé : In this paper, we examine the use of boundary springs as approximate external boundary conditions for the typical soil islands encountered in finite-element (FE) models of soil–foundation interaction problems. We present a set of simple uniformly distributed boundary springs and a set of variable boundary springs that account for the lateral distribution of contact forces between the foundation and the soil. We evaluate the accuracy of the approach for shallow foundations resting on soil islands of different dimensions. It is shown that significantly smaller errors can be achieved with these boundary springs than those obtained when fixed-fixed or fixed-free external boundary conditions are used. We present an iterative approach to determine the boundary springs for cases in which extremely small soil islands are required. Although the approach suggested to determine the boundary springs is best suited to shallow foundations, good results are also obtained for pile foundations. The approach presented applies to a uniform elastic half-space, but extensions to layered media are possible. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i10/p648_s1?isAuthorized=no [article] Approximate boundaries for finite - element models of static soil – foundation interaction problems [texte imprimé] / Carlos M. Mozos, Auteur ; J. Enrique Luco, Auteur . - 2012 . - pp.648-659. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 137 N° 10 (Octobre 2011) . - pp.648-659 Mots-clés : Soil-structure  interactions  Soil-pile  interactions  Finite  element  method  Boundaries Résumé : In this paper, we examine the use of boundary springs as approximate external boundary conditions for the typical soil islands encountered in finite-element (FE) models of soil–foundation interaction problems. We present a set of simple uniformly distributed boundary springs and a set of variable boundary springs that account for the lateral distribution of contact forces between the foundation and the soil. We evaluate the accuracy of the approach for shallow foundations resting on soil islands of different dimensions. It is shown that significantly smaller errors can be achieved with these boundary springs than those obtained when fixed-fixed or fixed-free external boundary conditions are used. We present an iterative approach to determine the boundary springs for cases in which extremely small soil islands are required. Although the approach suggested to determine the boundary springs is best suited to shallow foundations, good results are also obtained for pile foundations. The approach presented applies to a uniform elastic half-space, but extensions to layered media are possible. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i10/p648_s1?isAuthorized=no

Effect of hanger flexibility on dynamic response of suspension bridges / José Turmo in Journal of engineering mechanics, Vol. 136 N° 12 (Décembre 2010) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 136 N° 12 (Décembre 2010) . - pp.1444-1459 Titre : Effect of hanger flexibility on dynamic response of suspension bridges Type de document : texte imprimé Auteurs : José Turmo, Auteur ; J. Enrique Luco, Auteur Année de publication : 2011 Article en page(s) : pp.1444-1459 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Dynamic  loads  Bridges  suspension  Continuum  mechanics  Vibration. Résumé : Linearized continuum models of a suspended span with unloaded backstays and of a symmetric three-span suspension bridge are used to study the effects of the flexibility of the hangers on the vertical vibrations of suspension bridges. The models include elastic parabolic cables, flexible distributed hangers with variable length, and a stiffening girder represented by an elastic beam. It is shown that the free vibrations of a suspended span with unloaded backstays are controlled by five dimensionless parameters, while six dimensionless parameters control the response of a symmetric three-span suspension bridge. The results indicate that the flexibility of the hangers has a significant effect on the natural frequencies of the higher modes only when the relative stiffness of the girder is very high. The effects of hanger flexibility on the response of a suspension bridge to localized impulsive loads are also found to be small. These findings confirm the traditional, albeit previously untested, assumption of inextensible hangers. Finally, the threshold amplitudes of free vibrations that would result in the incipient slackening of the hangers are determined. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v136/i12/p1444_s1?isAuthorized=no [article] Effect of hanger flexibility on dynamic response of suspension bridges [texte imprimé] / José Turmo, Auteur ; J. Enrique Luco, Auteur . - 2011 . - pp.1444-1459. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 136 N° 12 (Décembre 2010) . - pp.1444-1459 Mots-clés : Dynamic  loads  Bridges  suspension  Continuum  mechanics  Vibration. Résumé : Linearized continuum models of a suspended span with unloaded backstays and of a symmetric three-span suspension bridge are used to study the effects of the flexibility of the hangers on the vertical vibrations of suspension bridges. The models include elastic parabolic cables, flexible distributed hangers with variable length, and a stiffening girder represented by an elastic beam. It is shown that the free vibrations of a suspended span with unloaded backstays are controlled by five dimensionless parameters, while six dimensionless parameters control the response of a symmetric three-span suspension bridge. The results indicate that the flexibility of the hangers has a significant effect on the natural frequencies of the higher modes only when the relative stiffness of the girder is very high. The effects of hanger flexibility on the response of a suspension bridge to localized impulsive loads are also found to be small. These findings confirm the traditional, albeit previously untested, assumption of inextensible hangers. Finally, the threshold amplitudes of free vibrations that would result in the incipient slackening of the hangers are determined. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v136/i12/p1444_s1?isAuthorized=no