本文是以斷面模型風洞試驗來探討斜張橋主梁幾何形狀與風攻角對於風力係數及氣動力參數的影響。試驗中選用了三種橋面版形狀:版梁斷面，箱型梁斷面，以及一個近似高屏溪橋的斷面。研究結果顯示:在三種斷面之中以箱型斷面呈現較佳的對稱性能減弱流場分離現象，形成較低的風力係數與較穩定的氣動力參數特性。改變風攻角時顯示本研究所選用的橋梁斷面在正風攻角時可能引起氣動力不穩定，在負風攻角時則增加橋梁的穩定性。以實驗方法求得各橋梁斷面之風力係數與氣動力參數後，代入數值分析模式計算其振顫臨界風速與亂流效應造成的橋梁動態反應，近似高屏溪橋斷面的顫振特性與相關文獻相當吻合。 In this paper, section model was used to study the effects of bridge deck shape and
wind attack angle on the flutter derivatives and wind force coefficients. Three deck geometry:
plate section, box section and one similar to Kao-Pin-Hsi bridge, were used. Experimental results indicate that the plate girder type, which possess asymmetric shape and prone to flow separation, has higher value of force coefficients and most unstable flutter derivatives. On the other hand, the box girder type has a better symmetric shape and fairing to weaken flow separation, therefore, exhibits lower value of force coefficients and more stable flutter derivatives. As for the wind attack angle, positive attack angle tends to cause aerodynamic instability, negative attack angle will stabilize bridge. The flutter derivatives and force coefficients were then applied to estimate flutter velocity and buffeting response of a cable stayed bridge with similar structural characteristics as Kao-Ping-Hsi bridge.
關聯:
中華民國第四屆結構工程研討會論文集(二)=Proceedings of the 4th National Conference on Structural Engineering，頁1135-1142
