钢桁架悬索桥颤振稳定性能研究

钢桁架悬索桥由于抗扭刚度较小其颤振稳定性通常难以满足抗风稳定性要求。本文以刘家峡大桥为例通过风洞试验研究了采取中央稳定板、导流板、封闭防撞栏等气动措施组合对钢桁架悬索桥颤振稳定性的影响。结果表明：上、下稳定板同时使用效果优于单独使用；将上稳定板做成分段布置时，正攻角的颤振临界风速会急剧降低。水平导流板外置比导流板内置于钢桁架内部效果好；加宽水平导流板可以使不同攻角颤振稳定性趋于均衡。加高并封闭防撞栏杆可以起到中央稳定板的作用，能有效提高桁架悬索桥不同攻角的颤振临界风速。

Flutter stability of a steel truss girder suspension bridge

The flutter stability of steel truss girder suspension bridge usually does not meet the requirement of wind-resistance stability as it is with low torsion rigidity. Based on Liujiaxia Bridge, wind tunnel tests were carried to investigate the different aerodynamic measures including central stability board, guide vane and the closed crash barrier influence on the flutter stability of steel truss girder suspension bridge. The results show that the upper central stability board and the lower central stability board used at the same time is better than used it separated. The flutter critical wind speed at positive wind attack angle decrease sharply when the upper central stability board is separated. The guide vane outside of the truss girder is better than install it inside the truss girder. The flutter stability at different wind attack angle becomes more balanced when the guide vane widened. Heighten and closed the crash barrier can play the same role of the central stability board, which can increases the flutter critical wind speed of the steel truss girder suspension bridge at different wind attack angle effectively.