교량 거더의 공기역학적 계수에 대한 준정상 해석
Comparison of Aerodynamic Derivatives based on Quasi-Steady Analysis with Experimental Test for Bridge Deck
1
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
공기역학적 현상중에서 물체에 작용하는 외부 공기력이 존재하지 않더라도 주기적인 물체의 진동에 의해 발생되는 유체에너지로부터 공기력이 생성된다. 이러한 메커니즘에 위해 생성되는 공기력을 자발공기력(self excited force)이라 하며 플러터 계수에 의해 산정된다. 유체흐름에서 발생되는 진동은 유속이 작은 경우, 교량 단면에 생기는 미소 교란으로 인하여 탄성진동이 발생하여도 교량의 진동에 따라 일어나는 공기력에 의해 감쇠된다. 하지만 유속이 증가하여 임계 풍속에 도달하면 교량은 부감쇠를 가지게되며 무한발산을 하게되며 결국 파괴에 이르게된다. 본 논문에서는 준정상 가정을 바탕으로 교량단면의 공기역학적 계수를 산정하며 기존 연구자들에 의해 제안된 산출식과 비교하고자 한다. 또한 대상단면(단면 1)에 대한 실험적 해석을 통해 각 연구자들의 산출식을 비교하였다.
Abstract
Movement-induced excitation (MIE) is due to aerodynamic forces that arise from movements of the vibration body oscillator. Even without an external exciting aerodynamic force, a body oscillator may undergo sustained vibration if there is an energy source from which the oscillator can extract energy during each cycle of free movement. Vibrations of this type are called self-excited and are related to aeroelastic instability. At a critical wind speed, commonly referred to as the negative damping threshold, this is related with aerodynamic derivatives obtained in static wind tunnel tests. In this paper, aerodynamic derivatives depend on the MIE mechanism are briefly described and a comparison researches on flutter derivatives based on the quasi-steady assumption are introduced from the point of aerodynamic force coefficients related with the aerodynamic derivatives. To compare the relation of aerodynamic and flutter derivatives, wind tunnel tests(sec-1) have been carried out on spring suspended section models.
참고문헌 (19)
- "Aeroelasticity, Dover Phoenic Editions" (1996)
- "Advanced analysis of coupled buffeting response of bridges: a complex modal decomposition approach", 17(2), pp.201~213 (2002)
- "Advances in Modeling of Aerodynamics Forces on Bridge Decks", 128(1), pp.1193~1205 (2002)
- "Assessment on Pile Effective Lengths and Their Effects on Design - I. Assessment", 62(2), pp.265~286 (1997)
- "Comparison of Methodology for Prediction of Flutter Velocity in Bridges Girder" (2006)
- "Experimental Investigation of Aerodynamic Force Coefficients and Flutter Derivatives of Bridge Girder Section (in Korean)", 26(5A), pp.887~899 (2006)
- "Numerical Analysis for the Evaluation of Buffeting Response of a Long Span Bridge in Turbulent Wind Flow (in Korean)", 10(1), pp.45~53 (2006)
- "The Flutter Coefficients Identification of Bridge Girders (in Korean)", 2(2), pp.224~232 (1998)
- "Study on the Estimation of Aerodynamic Admittance and Its Application to Buffeting Response (in Korean)", 3(2), pp.158~167 (1999)
- "State Space Formulation for Wind-Bridge Interaction Analysis(in Korean)", 5(2), pp.193~199 (2001)
- "Performance of streamlined bridge decks in relation to the aerodynamics of the airfoil", 69(71), pp.851~860 (1997)
- "Flutter and divergence aeroelastic characteristics for composite forward swept cantilevered wind", pp.1101~1107 (1985)
- "Analytical Investigation on the Response of a Very Long Suspension Bridge under Gusty Wind", pp.1006~1017 (1995)
- "1936. Zusammenfassender Bericht ？ber den Instationaren Auftrieb von Fl？geln", pp.410~424
- "The action of flexible bridges under wind. Part I" (1978)
- "1941. Some Aspects of Non-Stationary Airfoil Theory and its Practical Application. Journal of the Aeronautical Sciences", pp.104~108
- "1935. General theory of aerodynamic instability and the mechanism of flutter. NACA Technical Report 496 Twentieth Annual Report of the National Advisory Committee for Aeronautics 1934", pp.413~433
- "Relationships among aerodynamic admittance functions, flutter derivatives and static coefficients for long-span bridges", 93, pp.929~950 (2005)
- "1925. ？ber die Entstehung des Dynamicshen Auftriebes von Tragfl？geln. Zeit. Angew. Math u. Mechanics", pp.17~35