Documents disponibles écrits par cet auteur

Engineering approach for predicting fire response of restrained steel beams / Mahmud Dwaikat in Journal of engineering mechanics, Vol. 137 N° 7 (Juillet 2011) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 137 N° 7 (Juillet 2011) . - pp.447-461 Titre : Engineering approach for predicting fire response of restrained steel beams Type de document : texte imprimé Auteurs : Mahmud Dwaikat, Auteur ; Venkatesh Kodur, Auteur Année de publication : 2011 Article en page(s) : pp.447-461 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Axial  restraint  Catenary  action  Elasto-plastic  response  Fire  response  Fire  resistance  Local  buckling  Restrained  steel  beam  Rotational  restraint Résumé : Predicting the response of restrained beams under fire conditions is complex owing to the development of fire-induced forces and requires finite-element or finite-differences analysis. In this paper, a simplified approach is proposed for predicting the fire-induced forces and deflections of restrained steel beams. The method applies equilibrium equations for obtaining critical fire-induced forces and then utilizes compatibility principles for obtaining temperature-deflection history of the beam. Effect of end restraints, thermal gradient, location of axial restraint force, span length, and load intensity are accounted for in the proposed approach. The validation of the approach is established by comparing the predictions from the proposed approach with results obtained from rigorous finite-element analysis. The applicability of the proposed approach to practical design situations is illustrated through a numerical example. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i7/p447_s1?isAuthorized=no [article] Engineering approach for predicting fire response of restrained steel beams [texte imprimé] / Mahmud Dwaikat, Auteur ; Venkatesh Kodur, Auteur . - 2011 . - pp.447-461. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 137 N° 7 (Juillet 2011) . - pp.447-461 Mots-clés : Axial  restraint  Catenary  action  Elasto-plastic  response  Fire  response  Fire  resistance  Local  buckling  Restrained  steel  beam  Rotational  restraint Résumé : Predicting the response of restrained beams under fire conditions is complex owing to the development of fire-induced forces and requires finite-element or finite-differences analysis. In this paper, a simplified approach is proposed for predicting the fire-induced forces and deflections of restrained steel beams. The method applies equilibrium equations for obtaining critical fire-induced forces and then utilizes compatibility principles for obtaining temperature-deflection history of the beam. Effect of end restraints, thermal gradient, location of axial restraint force, span length, and load intensity are accounted for in the proposed approach. The validation of the approach is established by comparing the predictions from the proposed approach with results obtained from rigorous finite-element analysis. The applicability of the proposed approach to practical design situations is illustrated through a numerical example. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i7/p447_s1?isAuthorized=no

Modeling fracture and delamination of spray - applied fire - resisting materials under static and impact loads / Mahmud Dwaikat in Journal of engineering mechanics, Vol. 137 N° 12 (Decembre 2011) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 137 N° 12 (Decembre 2011) . - pp.901-910 Titre : Modeling fracture and delamination of spray - applied fire - resisting materials under static and impact loads Type de document : texte imprimé Auteurs : Mahmud Dwaikat, Auteur ; Venkatesh Kodur, Auteur Année de publication : 2012 Article en page(s) : pp.901-910 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Cracking  Material  properties  Fire  resistance  Static  loads  Impact  loads  Laminated  materials Résumé : A specially developed two-dimensional cohesive zone finite element (CZFE) scheme is applied to simulate the fracture and delamination phenomena that occur in spray-applied fire-resisting material (SFRM) on steel structures. A cohesive zone material model for the SFRM is introduced and utilized to model both the internal cohesion in SFRM and the interfacial adhesion at the steel-SFRM interface. The CZFE model is validated by comparing predictions from the model with results from an adhesion test conducted at ambient temperature. The validated model is successfully applied to simulate the spontaneous initiation and propagation of cracks in the SFRM under static and impact loads. Results from the numerical studies indicate that the proposed model is capable of predicting the initiation and propagation of cracks within the insulation material and at the interface. The results show that the development of transverse cracks in the insulation layer help prevent further delamination of the SFRM. Also, it was found that for larger thicknesses of insulation, delamination occurs at less direct tension or flexural stresses. Results from impact simulations show that there is an optimum insulation thickness for resisting the delamination induced by impact loads. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i12/p901_s1?isAuthorized=no [article] Modeling fracture and delamination of spray - applied fire - resisting materials under static and impact loads [texte imprimé] / Mahmud Dwaikat, Auteur ; Venkatesh Kodur, Auteur . - 2012 . - pp.901-910. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 137 N° 12 (Decembre 2011) . - pp.901-910 Mots-clés : Cracking  Material  properties  Fire  resistance  Static  loads  Impact  loads  Laminated  materials Résumé : A specially developed two-dimensional cohesive zone finite element (CZFE) scheme is applied to simulate the fracture and delamination phenomena that occur in spray-applied fire-resisting material (SFRM) on steel structures. A cohesive zone material model for the SFRM is introduced and utilized to model both the internal cohesion in SFRM and the interfacial adhesion at the steel-SFRM interface. The CZFE model is validated by comparing predictions from the model with results from an adhesion test conducted at ambient temperature. The validated model is successfully applied to simulate the spontaneous initiation and propagation of cracks in the SFRM under static and impact loads. Results from the numerical studies indicate that the proposed model is capable of predicting the initiation and propagation of cracks within the insulation material and at the interface. The results show that the development of transverse cracks in the insulation layer help prevent further delamination of the SFRM. Also, it was found that for larger thicknesses of insulation, delamination occurs at less direct tension or flexural stresses. Results from impact simulations show that there is an optimum insulation thickness for resisting the delamination induced by impact loads. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i12/p901_s1?isAuthorized=no