非均匀风下流线型箱梁悬索桥静风稳定性分析

大跨度悬索桥结构轻柔,风致响应明显.借助有限元方法,考虑悬索桥的几何非线性和位移荷载非线性,对非均风攻角来流沿主梁对称分布和非对称分布以及非均匀风速来流沿主梁对称分布和非对称分布时悬索桥的非线性静风稳定性展开研究.结果 表明:正攻角来流会降低桥梁的静风失稳临界风速,负攻角来流有利于桥梁抵抗静风失稳,且负攻角来流对桥梁的...

Aerostatic stability analysis of streamline box girder suspension bridge under non-uniform wind

The long-span suspension bridges, which are notable flexibility, are sensitive to wind load. Using the finite element method, considering the geometric nonlinearity and displacement-load nonlinearity, the aerostatic stability of suspension bridges is studied when the non-uniform wind attack angle flow and non-uniform wind speed flow distributes symmetrically and asymmetrically along the main girder. The results show that the flow of positive angle of attack will reduce the critical stability wind speed of the bridges, the flow of negative angle of attack is conducive to the bridges to resist the instability of static wind. The impact of negative angle of attack on the static wind stability of the bridge is greater than that of positive angle of attack. When the flow is asymmetrically distributed, the critical stability wind speed can be determined by small wind angle of attack. When the flow is symmetrically distributed, the mean angle of attack can be selected to measure the aerostatic stability of the bridge. Incoming flow with non-uniform wind speed has an adverse effect on the aerostatic stability of the bridge. Moreover, the influence of symmetric distribution of non-uniform wind speed is greater than that of asymmetric distribution of non-uniform wind speed.Under different initial angles of attack, this kind of incoming flow has similar effects on the static wind stability of the bridge. That''s to say, the critical wind speed of aerostatic stability of the bridge decreases with the increase of the unevenness of the wind speed.