斜风下扁平箱形截面桥梁颤振性能风洞试验研究

扁平箱形截面桥梁的颤振临界风速与风偏角的关系明显地受到风攻角的影响。在0°风攻角情况下,扁平箱形截面流线性好,其颤振性能与平板接近,颤振临界风速随风偏角的增加而增加,用传统的平均风分解方法可以获得较好的结果;而对于非0°风攻角的情况,扁平箱形截面的流线性变差,随着风偏角的增加其颤振临界风速呈起伏变化,最低值一般在斜风的情况下出现,此时,传统的平均风分解方法不再适用。

Study of Flutter Performance of Flat Box Deck Bridge under Skew Wind via Wind Tunnel Test

The variation pattern between flutter critical wind speed of bridge with flat box deck and wind yaw angle is significantly affected by wind attack angle.In the case of zero attack angle,the flat box deck is good in its streamline shape,and the flutter performance of the deck is similar to that of the flat plate deck.The flutter critical wind speed rises with the increase of the wind yaw angle,and a good estimate can be achieved with conventional approach of mean wind decomposition.However,in the case of non-zero attack angle,the flat box deck becomes bluff,the variation of its flutter critical wind speed is accordingly undulant as the wind yaw angle increases,and the lowest value will occur generally under skew wind.In such case,the conventional approach of mean wind decomposition is no longer adequate for estimating the flutter critical wind speed of bridges under the skew wind.