Documents disponibles écrits par cet auteur

Influence of surrounding buildings on wind loads acting on low-rise building / Yong Chul Kim in Journal of structural engineering, Vol. 139 N° 2 (Février 2013) 

Public ISBD [article]  in Journal of structural engineering > Vol. 139 N° 2 (Février 2013) . - pp. 275–283 Titre : Influence of surrounding buildings on wind loads acting on low-rise building Type de document : texte imprimé Auteurs : Yong Chul Kim, Auteur ; Akihito Yoshida, Auteur ; Yukio Tamura, Auteur Année de publication : 2013 Article en page(s) : pp. 275–283 Note générale : structural engineering Langues : Anglais (eng) Mots-clés : low-rise  buildings;  buildings;  wind  tunnels;  wind  loads Résumé : A large number of wind pressure experiments have been performed to investigate the influence of surrounding buildings on wind pressures and forces on a cubical low-rise building. The primary purpose of the present work was to understand the effects of surrounding buildings and to examine methods for estimating wind loads. The considered parameters were area density and upstream distance under a turbulent boundary layer representing a suburban area. Results show that wind pressures decrease with increasing area density because of the surrounding buildings, but the variations of mean and fluctuating components within one area density are relatively small. The local wind pressure coefficients increase significantly, and this is originated from the rapid decrease in the local velocity pressure at the model position. Last, after discussing the design approach of a target low-rise building in a large group, a methodology for estimating wind loads on a target low-rise building was examined by introducing the (zoning) interference factor. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000625 [article] Influence of surrounding buildings on wind loads acting on low-rise building [texte imprimé] / Yong Chul Kim, Auteur ; Akihito Yoshida, Auteur ; Yukio Tamura, Auteur . - 2013 . - pp. 275–283. structural engineering Langues : Anglais (eng) in Journal of structural engineering > Vol. 139 N° 2 (Février 2013) . - pp. 275–283 Mots-clés : low-rise  buildings;  buildings;  wind  tunnels;  wind  loads Résumé : A large number of wind pressure experiments have been performed to investigate the influence of surrounding buildings on wind pressures and forces on a cubical low-rise building. The primary purpose of the present work was to understand the effects of surrounding buildings and to examine methods for estimating wind loads. The considered parameters were area density and upstream distance under a turbulent boundary layer representing a suburban area. Results show that wind pressures decrease with increasing area density because of the surrounding buildings, but the variations of mean and fluctuating components within one area density are relatively small. The local wind pressure coefficients increase significantly, and this is originated from the rapid decrease in the local velocity pressure at the model position. Last, after discussing the design approach of a target low-rise building in a large group, a methodology for estimating wind loads on a target low-rise building was examined by introducing the (zoning) interference factor. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000625

Performance and cost evaluation of a smart tuned mass damper for suppressing wind-induced lateral-torsional motion of tall structures / K. T. Tse 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. 514–525 Titre : Performance and cost evaluation of a smart tuned mass damper for suppressing wind-induced lateral-torsional motion of tall structures Type de document : texte imprimé Auteurs : K. T. Tse, Auteur ; Kwok, K. C. S., Auteur ; Yukio Tamura, Auteur Année de publication : 2012 Article en page(s) : pp. 514–525 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Lateral-torsional  motion  Structural  optimization  STMD  Damper  pricing  chart Résumé : The implementation of a vibration control system has always been associated with considerable capital and long-standing maintenance costs, resulting in limited practical applications of damping devices. The notion of a massive implementation cost is largely the result of a lack of cost analysis of vibration control systems in the literature. This paper presents the structural design of a wind-sensitive tall building at various design stages and the results of a collaborative study with two damper construction companies on the cost estimation of a control device. A series of wind tunnel pressure tests were conducted on a 1∶400 scale model to determine the translational and torsional wind forces acting on the studied building. A structural optimization was subsequently employed to reduce the excessive top deflection, and a smart tuned mass damper was implemented at the final design stage to meet occupant comfort criteria. The details of each structural design stage, the implementation of vibration control devices, and a collaborative study on damper cost are outlined in this paper. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000486 [article] Performance and cost evaluation of a smart tuned mass damper for suppressing wind-induced lateral-torsional motion of tall structures [texte imprimé] / K. T. Tse, Auteur ; Kwok, K. C. S., Auteur ; Yukio Tamura, Auteur . - 2012 . - pp. 514–525. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 4 (Avril 2012) . - pp. 514–525 Mots-clés : Lateral-torsional  motion  Structural  optimization  STMD  Damper  pricing  chart Résumé : The implementation of a vibration control system has always been associated with considerable capital and long-standing maintenance costs, resulting in limited practical applications of damping devices. The notion of a massive implementation cost is largely the result of a lack of cost analysis of vibration control systems in the literature. This paper presents the structural design of a wind-sensitive tall building at various design stages and the results of a collaborative study with two damper construction companies on the cost estimation of a control device. A series of wind tunnel pressure tests were conducted on a 1∶400 scale model to determine the translational and torsional wind forces acting on the studied building. A structural optimization was subsequently employed to reduce the excessive top deflection, and a smart tuned mass damper was implemented at the final design stage to meet occupant comfort criteria. The details of each structural design stage, the implementation of vibration control devices, and a collaborative study on damper cost are outlined in this paper. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000486

Shear effects on flow past a square cylinder at moderate reynolds numbers / Shuyang Cao in Journal of engineering mechanics, Vol. 138 N° 1 (Janvier 2012) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 138 N° 1 (Janvier 2012) . - pp.116- 123 Titre : Shear effects on flow past a square cylinder at moderate reynolds numbers Type de document : texte imprimé Auteurs : Shuyang Cao, Auteur ; Yaojun Ge, Auteur ; Yukio Tamura, Auteur Année de publication : 2012 Article en page(s) : pp.116- 123 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Aerodynamic  force  Direct  numerical  simulation  Large  eddy  simulation  Shear  parameter  Vortex  shedding  Wake  dynamics Résumé : Direct numerical simulation (DNS) and large eddy simulation (LES) with a dynamic Smagorinsky subgrid model are performed to investigate the flow past a square cylinder under the influence of velocity shear at the inlet at moderate Reynolds numbers ( R=150–1,000 ). The shear rate is expressed by a dimensionless shear parameter β , which is based on the velocity gradient, side length of the cylinder, and upstream velocity at the center plane of the cylinder. Shear parameter varies from 0 to 0.2 in this study. Several Reynolds numbers are considered to study the Reynolds number dependence and the Strouhal number were found to have no significant variation with the shear parameter. The peak frequency of drag coefficient fluctuation becomes identical with that of the lift force coefficient when β>0.1 . The vortices on the low-velocity side disappear in the far wake under the strong shear condition. The stagnation point moves to the high-velocity side and the movement increases with an increase in shear parameter. An interesting finding is that the lift force acts from the low-velocity to the high-velocity side, which is opposite to the case of a circular cylinder under the same inflow situation, whereas the drag force shows little variation with shear parameter. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000309 [article] Shear effects on flow past a square cylinder at moderate reynolds numbers [texte imprimé] / Shuyang Cao, Auteur ; Yaojun Ge, Auteur ; Yukio Tamura, Auteur . - 2012 . - pp.116- 123. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 138 N° 1 (Janvier 2012) . - pp.116- 123 Mots-clés : Aerodynamic  force  Direct  numerical  simulation  Large  eddy  simulation  Shear  parameter  Vortex  shedding  Wake  dynamics Résumé : Direct numerical simulation (DNS) and large eddy simulation (LES) with a dynamic Smagorinsky subgrid model are performed to investigate the flow past a square cylinder under the influence of velocity shear at the inlet at moderate Reynolds numbers ( R=150–1,000 ). The shear rate is expressed by a dimensionless shear parameter β , which is based on the velocity gradient, side length of the cylinder, and upstream velocity at the center plane of the cylinder. Shear parameter varies from 0 to 0.2 in this study. Several Reynolds numbers are considered to study the Reynolds number dependence and the Strouhal number were found to have no significant variation with the shear parameter. The peak frequency of drag coefficient fluctuation becomes identical with that of the lift force coefficient when β>0.1 . The vortices on the low-velocity side disappear in the far wake under the strong shear condition. The stagnation point moves to the high-velocity side and the movement increases with an increase in shear parameter. An interesting finding is that the lift force acts from the low-velocity to the high-velocity side, which is opposite to the case of a circular cylinder under the same inflow situation, whereas the drag force shows little variation with shear parameter. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000309