교량 거더의 공기역학적 계수에 대한 준정상 해석 = Comparison of Aerodynamic Derivatives based on Quasi-Steady Analysis with Experimental Test for Bridge Deck

국문 초록 (Abstract)

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.

다국어 초록 (Multilingual 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.

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