本文主要目的乃針對S曲線人行斜張橋之氣動力行為作一探討，當曲線橋梁受風作用時，其風向角是沿著橋軸連續變化的。由於傳統上的顫振與抖振理論是由直線橋梁發展而來，因此無法直接應用在此類橋梁上。在過去經常使用餘弦法則以及斜風理論等近似理論來處理有風向角下的橋梁顫振臨界風速以及抖振反應的問題，但是，這些近似理論僅能適用於風向角較小的情況下。本文針對曲線橋梁的顫振臨界風速以及抖振反應發展出一套分析方法;在此分析方法下，考慮橋梁在特定風攻角及風向角連續變化情況，推導顫振與抖振理論。另外為了證明此方法實際可行，額外再建立一組等值的直線數值橋梁與曲線數值橋梁作一研究比較。研究結果指出，曲線橋梁的顫振臨界風速高於等值直線橋梁，而抖振反應則因曲線橋梁結構振態間耦合的關係而高於等值直線橋梁。 The paper discusses the Aerodynamic Stability of S shaped curved cable-stayed bridges. As the curved bridge is subjected to wind excitation, the yaw angles along the bridge axis are continuously changing because of the curved nature. Traditional flutter and buffeting theories, developed for straight beams, cannot be directly applied for this type of bridges. In the past, for dealing with the buffeting responses and flutter critical wind speed in the case of the bridge subjected to yawed winds, the "cosine rule" and "skew wind theory" were often used. However, these approximate theories are only valid for the small yawed angles. This study developed a method for evaluating buffeting response and flutter critical wind speed for curved bridges. The method is based on yaw angles that are continuously changing at specific inclination. For practical use, an equivalent straight bridge structural model was also employed to compare with the curved bridge. The results show the flutter critical wind speed of the curved bridge is higher than that of the equivalent straight bridge. However, the buffeting responses of the curved bridge are larger for the contribution of the structural coupling.
中華民國第八屆結構工程研討會論文集=Proceedings of the 8th National Conference on Structural Engineering，12頁