• Title/Summary/Keyword: 공력 어드미턴스 함수

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Buffeting Responses of Concrete Cable-stayed Bridge Considering Turbulent Characteristics of Bridge Site (현장 풍속 특성을 반영한 콘크리트 사장교의 버페팅 응답)

  • Kim, Sung-Ho;Yhim, Sung Soon;Kwon, Soon-Duck
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.2A
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    • pp.97-104
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    • 2011
  • This study presents the aerodynamic admittance function of bridge girder under turbulent flow generated from wind velocity spectrum measured at bridge site. Three dimensional buffeting analysis of concrete cable-stayed bridge were performed considering aerodynamic admittance functions obtained from four different methods. It is revealed from the analysis that vertical buffeting responses considering proper aerodynamic admittance functions were just half of that neglecting aerodynamic admittance function. Grid turbulence was found to relatively lower the aerodynamic admittance function at low frequency range, and to underestimate the buffeting wind forces. It is recommended to use the aerodynamic admittance function evaluated from flutter derivatives or measured at active turbulence in order to properly predict the buffeting responses of bridges.

Aerodynamic Characteristics of Long-Span Bridges under Actively Generated Turbulences (능동 난류 생성을 통한 장대 교량의 공력 특성 비교)

  • Lee, Seungho;Kwon, Soon-Duck
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.5A
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    • pp.341-349
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    • 2011
  • The main purpose of this study is to investigate the affect of various turbulence properties on aerodynamic characteristics of twin box bridge section. To achieve this goal, active turbulence generator which successfully simulated various target turbulences was developed in the wind tunnel. From the wind tunnel tests, turbulence integral length scale did not affect on the aerodynamic forces and flutter derivatives except for the $A_1^*$ curve. Turbulence intensity gave slight effect on the unsteady aerodynamic force, but turbulence integral length scale did not affect the self-excited forces except vertical direction component.