Documents disponibles écrits par cet auteur

Active shear planes of bolted connections failing in block shear / Drew D. A. Clements in Journal of structural engineering, Vol. 139 N° 3 (Mars 2013)

Public ISBD [article]  in Journal of structural engineering > Vol. 139 N° 3 (Mars 2013) . - pp. 320–327 Titre : Active shear planes of bolted connections failing in block shear Type de document : texte imprimé Auteurs : Drew D. A. Clements, Auteur ; Teh, Lip H., Auteur Année de publication : 2013 Article en page(s) : pp. 320–327 Note générale : structural engineering Langues : Anglais (eng) Mots-clés : bolted  connections;  cold-formed  steel;  shear  failures;  steel  plates;  tensile  strength Résumé : In the steel design codes worldwide, the shear area for calculating the block shear capacity of a bolted connection is either the gross or the net shear area. The authors have previously noted independent experimental evidence indicating the shear failure planes to lie midway between the gross and the net shear planes, termed the active shear planes. This paper presents the nonlinear contact finite brick element analysis results that confirm the location of the active shear planes, indicated by regions of maximum shear stresses. The finite-element analysis also found that shear stresses approach zero toward the free downstream end of the connection block. The veracity of the active shear area is further demonstrated in terms of the ability of the resulting block shear equation to predict the governing failure modes of test specimens consistently, in comparison with the equations assuming the gross and the net shear areas. [article] Active shear planes of bolted connections failing in block shear [texte imprimé] / Drew D. A. Clements, Auteur ; Teh, Lip H., Auteur . - 2013 . - pp. 320–327. structural engineering Langues : Anglais (eng) in Journal of structural engineering > Vol. 139 N° 3 (Mars 2013) . - pp. 320–327 Mots-clés : bolted  connections;  cold-formed  steel;  shear  failures;  steel  plates;  tensile  strength Résumé : In the steel design codes worldwide, the shear area for calculating the block shear capacity of a bolted connection is either the gross or the net shear area. The authors have previously noted independent experimental evidence indicating the shear failure planes to lie midway between the gross and the net shear planes, termed the active shear planes. This paper presents the nonlinear contact finite brick element analysis results that confirm the location of the active shear planes, indicated by regions of maximum shear stresses. The finite-element analysis also found that shear stresses approach zero toward the free downstream end of the connection block. The veracity of the active shear area is further demonstrated in terms of the ability of the resulting block shear equation to predict the governing failure modes of test specimens consistently, in comparison with the equations assuming the gross and the net shear areas.

Block shear capacity of bolted connections in cold-reduced steel sheets / Teh, Lip H. in Journal of structural engineering, Vol. 138 N° 4 (Avril 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 4 (Avril 2012) . - pp. 459–467 Titre : Block shear capacity of bolted connections in cold-reduced steel sheets Type de document : texte imprimé Auteurs : Teh, Lip H., Auteur ; Drew D. A. Clements, Auteur Année de publication : 2012 Article en page(s) : pp. 459–467 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Bolted  connections  Cold-formed  steel  Shear  failures  Steel  plates  Tensile  strength Résumé : This paper examines the mechanisms for block shear failures of bolted connections in steel plates postulated in the design equations specified in the North American, European, and Australian steel structures codes. It explains that there is only one feasible mechanism for the limit state of conventional block shear failure, that which involves tensile rupture and shear yielding, regardless of the steel material ductility. It describes the fundamental shortcomings of various code equations for determining the block shear capacity of a bolted connection. Based on the tensile rupture and shear yielding mechanism, an in-plane shear lag factor, and the active shear resistance planes identified in the present work, this paper proposes a rational equation that is demonstrated to provide more accurate results than all the code equations in predicting the block shear capacities of bolted connections in G450 steel sheets subjected to concentric loading. The resistance factor of 0.8 for the proposed equation is computed with respect to the LRFD approach given in the North American specification for the design of cold-formed steel structures. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000478 [article] Block shear capacity of bolted connections in cold-reduced steel sheets [texte imprimé] / Teh, Lip H., Auteur ; Drew D. A. Clements, Auteur . - 2012 . - pp. 459–467. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 4 (Avril 2012) . - pp. 459–467 Mots-clés : Bolted  connections  Cold-formed  steel  Shear  failures  Steel  plates  Tensile  strength Résumé : This paper examines the mechanisms for block shear failures of bolted connections in steel plates postulated in the design equations specified in the North American, European, and Australian steel structures codes. It explains that there is only one feasible mechanism for the limit state of conventional block shear failure, that which involves tensile rupture and shear yielding, regardless of the steel material ductility. It describes the fundamental shortcomings of various code equations for determining the block shear capacity of a bolted connection. Based on the tensile rupture and shear yielding mechanism, an in-plane shear lag factor, and the active shear resistance planes identified in the present work, this paper proposes a rational equation that is demonstrated to provide more accurate results than all the code equations in predicting the block shear capacities of bolted connections in G450 steel sheets subjected to concentric loading. The resistance factor of 0.8 for the proposed equation is computed with respect to the LRFD approach given in the North American specification for the design of cold-formed steel structures. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000478

Tension capacity of staggered bolted connections in cold-reduced steel sheets / Teh, Lip H. in Journal of structural engineering, Vol. 138 N° 6 (Juin 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 6 (Juin 2012) . - pp. 769–776 Titre : Tension capacity of staggered bolted connections in cold-reduced steel sheets Type de document : texte imprimé Auteurs : Teh, Lip H., Auteur ; Drew D. A. Clements, Auteur Année de publication : 2012 Article en page(s) : pp. 769–776 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Cold-reduced  steel  sheet  Net  section  tension  strength  Staggered  bolts Résumé : This paper examines the assumption implicit in Cochrane’s formula that stresses are uniformly distributed across the net section of a staggered bolted connection. The assumption was found to be overoptimistic for connections in steel having low ductility, leading to unconservative estimates for the tension capacity if the in-plane shear lag is not accounted for. The reduction factor of 0.9 specified in the North American specification for cold-formed steel structures partially, but not wholly, addresses the problems inherent in the code equations. This paper points out that the simplification of Cochrane’s original formula into the standard formula used in steel design codes worldwide can lead to additional design capacity that may not be justified. It proposes an equation that accounts for the in-plane shear lag and incorporates Cochrane’s original formula for determining the net section area. The proposed equation is demonstrated through laboratory tests on 74 staggered bolted connection specimens in 1.5 mm and 3.0 mm G450 sheet steel to be more accurate and consistent than the code equations in predicting the net section tension capacity. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000514 [article] Tension capacity of staggered bolted connections in cold-reduced steel sheets [texte imprimé] / Teh, Lip H., Auteur ; Drew D. A. Clements, Auteur . - 2012 . - pp. 769–776. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 6 (Juin 2012) . - pp. 769–776 Mots-clés : Cold-reduced  steel  sheet  Net  section  tension  strength  Staggered  bolts Résumé : This paper examines the assumption implicit in Cochrane’s formula that stresses are uniformly distributed across the net section of a staggered bolted connection. The assumption was found to be overoptimistic for connections in steel having low ductility, leading to unconservative estimates for the tension capacity if the in-plane shear lag is not accounted for. The reduction factor of 0.9 specified in the North American specification for cold-formed steel structures partially, but not wholly, addresses the problems inherent in the code equations. This paper points out that the simplification of Cochrane’s original formula into the standard formula used in steel design codes worldwide can lead to additional design capacity that may not be justified. It proposes an equation that accounts for the in-plane shear lag and incorporates Cochrane’s original formula for determining the net section area. The proposed equation is demonstrated through laboratory tests on 74 staggered bolted connection specimens in 1.5 mm and 3.0 mm G450 sheet steel to be more accurate and consistent than the code equations in predicting the net section tension capacity. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000514