Documents disponibles écrits par cet auteur

Experimental validation of replaceable shear links for eccentrically braced steel frames / Nabil Mansour in Journal of structural engineering, Vol. 137 N° 10 (Octobre 2011) 

Public ISBD [article]  in Journal of structural engineering > Vol. 137 N° 10 (Octobre 2011) . - pp. 1141-1152 Titre : Experimental validation of replaceable shear links for eccentrically braced steel frames Type de document : texte imprimé Auteurs : Nabil Mansour, Auteur ; Christopoulos, Constantin, Auteur ; Robert Tremblay, Auteur Année de publication : 2012 Article en page(s) : pp. 1141-1152 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Aftershocks  Eccentrically  braced  steel  frames  Shear  link  Bolted  connection  Replaceable  link  Inelastic  rotations  Bearing Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : In the current design of steel eccentrically braced frames (EBFs), the yielding link is coupled with the floor beam. This often results in oversized link elements, which leads to overdesigned structures and foundations. In addition, the beams are expected to sustain significant damage through repeated inelastic deformations under design-level earthquakes, and thus the structure may require extensive repair or replacement. These drawbacks can be mitigated by designing EBFs with replaceable shear links. Two different replaceable link types with alternate section profiles, connection configurations, welding details, and intermediate stiffener spacings were tested. A total of 13 cyclic quasi-static full-scale cyclic tests were performed, including tests on EBFs with replaceable shear links, to study their inelastic seismic performance. The links exhibited a very good ductile behavior, developing stable and repeatable yielding. Additional inelastic rotation capacity can be achieved with bolted replaceable links when bolt bearing deformations are allowed to occur. The on-site replaceability of the link sections is confirmed even in the presence of residual deformations of 0.5% drift. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i10/p1141_s1?isAuthorized=no [article] Experimental validation of replaceable shear links for eccentrically braced steel frames [texte imprimé] / Nabil Mansour, Auteur ; Christopoulos, Constantin, Auteur ; Robert Tremblay, Auteur . - 2012 . - pp. 1141-1152. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 137 N° 10 (Octobre 2011) . - pp. 1141-1152 Mots-clés : Aftershocks  Eccentrically  braced  steel  frames  Shear  link  Bolted  connection  Replaceable  link  Inelastic  rotations  Bearing Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : In the current design of steel eccentrically braced frames (EBFs), the yielding link is coupled with the floor beam. This often results in oversized link elements, which leads to overdesigned structures and foundations. In addition, the beams are expected to sustain significant damage through repeated inelastic deformations under design-level earthquakes, and thus the structure may require extensive repair or replacement. These drawbacks can be mitigated by designing EBFs with replaceable shear links. Two different replaceable link types with alternate section profiles, connection configurations, welding details, and intermediate stiffener spacings were tested. A total of 13 cyclic quasi-static full-scale cyclic tests were performed, including tests on EBFs with replaceable shear links, to study their inelastic seismic performance. The links exhibited a very good ductile behavior, developing stable and repeatable yielding. Additional inelastic rotation capacity can be achieved with bolted replaceable links when bolt bearing deformations are allowed to occur. The on-site replaceability of the link sections is confirmed even in the presence of residual deformations of 0.5% drift. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i10/p1141_s1?isAuthorized=no

Residual drift response of SMRFs and BRB frames in steel buildings designed according to ASCE 7-05 / Jeffrey Erochko in Journal of structural engineering, Vol. 137 N° 5 (Mai 2011) 

Public ISBD [article]  in Journal of structural engineering > Vol. 137 N° 5 (Mai 2011) . - pp. 589-599 Titre : Residual drift response of SMRFs and BRB frames in steel buildings designed according to ASCE 7-05 Type de document : texte imprimé Auteurs : Jeffrey Erochko, Auteur ; Christopoulos, Constantin, Auteur ; Robert Tremblay, Auteur Année de publication : 2011 Article en page(s) : pp. 589-599 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Nonlinear  response  Residual  drifts  Steel  frames  Aftershocks Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : A recent study has shown that residual drifts after earthquakes that are greater than 0.5% in buildings may represent a complete loss of the structure from an economic perspective. To study the comparative residual drift response of special moment-resisting frames (SMRFs) and buckling-restrained braced (BRB) frames, buildings between 2 and 12 stories in height are designed according to ASCE 7-05 and investigated numerically. This investigation includes pushover analyses as well as two-dimensional nonlinear time-history analyses for two ground motion hazard levels. The two systems show similar peak drifts and drift concentration factors. The BRB frames experience larger residual drifts than the SMRFs; however, the scatter in the residual drift results is large. Expressions are proposed to estimate the residual drifts of these systems as a function of the expected peak drifts, the initial recoverable elastic drift, and the drift concentration factor of each system. When subjected to a second identical earthquake, both framing systems experienced larger-than-expected drifts when an initial drift greater than 0.5% was present. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i5/p589_s1?isAuthorized=no [article] Residual drift response of SMRFs and BRB frames in steel buildings designed according to ASCE 7-05 [texte imprimé] / Jeffrey Erochko, Auteur ; Christopoulos, Constantin, Auteur ; Robert Tremblay, Auteur . - 2011 . - pp. 589-599. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 137 N° 5 (Mai 2011) . - pp. 589-599 Mots-clés : Nonlinear  response  Residual  drifts  Steel  frames  Aftershocks Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : A recent study has shown that residual drifts after earthquakes that are greater than 0.5% in buildings may represent a complete loss of the structure from an economic perspective. To study the comparative residual drift response of special moment-resisting frames (SMRFs) and buckling-restrained braced (BRB) frames, buildings between 2 and 12 stories in height are designed according to ASCE 7-05 and investigated numerically. This investigation includes pushover analyses as well as two-dimensional nonlinear time-history analyses for two ground motion hazard levels. The two systems show similar peak drifts and drift concentration factors. The BRB frames experience larger residual drifts than the SMRFs; however, the scatter in the residual drift results is large. Expressions are proposed to estimate the residual drifts of these systems as a function of the expected peak drifts, the initial recoverable elastic drift, and the drift concentration factor of each system. When subjected to a second identical earthquake, both framing systems experienced larger-than-expected drifts when an initial drift greater than 0.5% was present. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i5/p589_s1?isAuthorized=no

Seismic performance of low-to-moderate height eccentrically braced steel frames designed for north american seismic conditions / Sanda Koboevic in Journal of structural engineering, Vol. 138 N° 12 (Décembre 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 12 (Décembre 2012) . - pp. 1465–1476 Titre : Seismic performance of low-to-moderate height eccentrically braced steel frames designed for north american seismic conditions Type de document : texte imprimé Auteurs : Sanda Koboevic, Auteur ; Jonathan Rozon, Auteur ; Robert Tremblay, Auteur Année de publication : 2013 Article en page(s) : pp. 1465–1476 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Seismic  design  Nonlinear  time  history  analysis  Global  dynamic  response  Steel  structures  Eccentrically  braced  frames Résumé : The global seismic response of 3- and 8-story eccentrically braced frames (EBFs), designed for western and eastern North American locations, is studied using nonlinear time history analysis. Analytical models were built in three computer programs. Similar maximum forces were obtained, but the inelastic deformation predictions at the element and global structural levels showed sensitivity to the modeling employed. This feature should be considered in seismic performance assessment or design. Current design methods failed to predict interstory drifts and plastic link rotations, but the study confirmed the strong correlation between the two parameters associated with rigid-plastic behavior. The influence of yielding and flexural buckling of frame members, other than the links on the global frame performance, was evaluated using the OpenSees model. It was confirmed that the flexural yielding of outer beams is acceptable for EBFs with short and intermediate links, if the combined flexural strength of the braces and beams is at least equal to the expected end-link moments and the braces can resist the associated axial force-bending moment demand. Inelastic response of braces and columns in such frames did not negatively impact the overall frame behavior. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000433 [article] Seismic performance of low-to-moderate height eccentrically braced steel frames designed for north american seismic conditions [texte imprimé] / Sanda Koboevic, Auteur ; Jonathan Rozon, Auteur ; Robert Tremblay, Auteur . - 2013 . - pp. 1465–1476. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 12 (Décembre 2012) . - pp. 1465–1476 Mots-clés : Seismic  design  Nonlinear  time  history  analysis  Global  dynamic  response  Steel  structures  Eccentrically  braced  frames Résumé : The global seismic response of 3- and 8-story eccentrically braced frames (EBFs), designed for western and eastern North American locations, is studied using nonlinear time history analysis. Analytical models were built in three computer programs. Similar maximum forces were obtained, but the inelastic deformation predictions at the element and global structural levels showed sensitivity to the modeling employed. This feature should be considered in seismic performance assessment or design. Current design methods failed to predict interstory drifts and plastic link rotations, but the study confirmed the strong correlation between the two parameters associated with rigid-plastic behavior. The influence of yielding and flexural buckling of frame members, other than the links on the global frame performance, was evaluated using the OpenSees model. It was confirmed that the flexural yielding of outer beams is acceptable for EBFs with short and intermediate links, if the combined flexural strength of the braces and beams is at least equal to the expected end-link moments and the braces can resist the associated axial force-bending moment demand. Inelastic response of braces and columns in such frames did not negatively impact the overall frame behavior. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000433

Shake table testing of slender RC shear walls subjected to eastern north america seismic ground motions / Iman Ghorbanirenani in Journal of structural engineering, Vol. 138 N° 12 (Décembre 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 12 (Décembre 2012) . - pp. 1515–1529 Titre : Shake table testing of slender RC shear walls subjected to eastern north america seismic ground motions Type de document : texte imprimé Auteurs : Iman Ghorbanirenani, Auteur ; Robert Tremblay, Auteur ; Pierre Léger, Auteur Année de publication : 2013 Article en page(s) : pp. 1515–1529 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Ductility  Dynamic  Experimental  tests  Higher  modes  Inelastic  response  Seismic  responses  Shear  wall Résumé : This paper presents shake table test results on two identical 1:0.429 scaled, 8-story moderately ductile RC shear wall specimens under the expected high-frequency ground motion in eastern North America. The walls were designed and detailed according to the seismic provisions of the NBCC 2005 and CSA-A23.3-04 standards. The objectives were to validate and understand the inelastic responses and interaction of shear and flexure and axial loads in the plastic hinge zones of the walls taking into consideration the higher-mode effects. One specimen was tested under incremental ground motion intensities ranging from 40 to 120% of the design level. The intensity range was increased from 100 to 200% for the second specimen. The response of the walls was significantly affected by the second mode, causing an inelastic flexural response to develop at the base as well as at the sixth level. Dynamic amplification of the base shear forces was also observed in both walls. In the second wall, which was tested in the undamaged condition, peak base shear forces occurred prior to significant inelastic rotation and the contribution to concrete of shear resistance exceeded the value used in the design. Once inelastic rotation had developed that contribution corresponded to the value obtained using a value of 0.18 for the reduction factor accounting for concrete cracking. Inelastic rotation in the upper wall region was found to limit the force demand imposed by the higher-mode response. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000581 [article] Shake table testing of slender RC shear walls subjected to eastern north america seismic ground motions [texte imprimé] / Iman Ghorbanirenani, Auteur ; Robert Tremblay, Auteur ; Pierre Léger, Auteur . - 2013 . - pp. 1515–1529. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 12 (Décembre 2012) . - pp. 1515–1529 Mots-clés : Ductility  Dynamic  Experimental  tests  Higher  modes  Inelastic  response  Seismic  responses  Shear  wall Résumé : This paper presents shake table test results on two identical 1:0.429 scaled, 8-story moderately ductile RC shear wall specimens under the expected high-frequency ground motion in eastern North America. The walls were designed and detailed according to the seismic provisions of the NBCC 2005 and CSA-A23.3-04 standards. The objectives were to validate and understand the inelastic responses and interaction of shear and flexure and axial loads in the plastic hinge zones of the walls taking into consideration the higher-mode effects. One specimen was tested under incremental ground motion intensities ranging from 40 to 120% of the design level. The intensity range was increased from 100 to 200% for the second specimen. The response of the walls was significantly affected by the second mode, causing an inelastic flexural response to develop at the base as well as at the sixth level. Dynamic amplification of the base shear forces was also observed in both walls. In the second wall, which was tested in the undamaged condition, peak base shear forces occurred prior to significant inelastic rotation and the contribution to concrete of shear resistance exceeded the value used in the design. Once inelastic rotation had developed that contribution corresponded to the value obtained using a value of 0.18 for the reduction factor accounting for concrete cracking. Inelastic rotation in the upper wall region was found to limit the force demand imposed by the higher-mode response. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000581