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以某斜拉桥为例,基于欧拉-欧拉理论,采用单向耦合的方法数值模拟风速为10,15,20 m/s条件下的桥面积雪的不均匀分布。同时,通过风洞试验研究3种不同风速下积雪的不均匀分布对主梁三分力系数、涡激振动性能以及颤振导数的影响。结果表明,积雪的沉积、侵蚀与壁面摩擦速度有紧密的联系,桥面背风侧积雪侵蚀量明显比迎风侧侵蚀量小,在尾流处侵蚀量最小。积雪对主梁的三分力系数影响较大,升力系数与扭矩系数绝对值增大40%左右,阻力系数绝对值增大15%左右。由于积雪作用,主梁+3°竖向涡激振动消失,同时,颤振导数A*4曲线斜率由负变为正,且不同风速下的积雪形状影响较小;当无量纲折减风速增大到一定程度时,H*2曲线相对平缓,而H*4基本保持不变。
Taking a cable - stayed bridge as an example, a unidirectional coupling method is used to numerically simulate the non - uniform snow distribution on the bridge deck under wind speed of 10, 15 and 20 m / s based on the Euler - Euler theory. At the same time, the wind tunnel test was conducted to study the influence of uneven snow distribution on the third-part force coefficient, vortex-induced vibration performance and flutter derivative of the main girder under three different wind speeds. The results show that the deposition and erosion of snow cover are closely related to the friction velocity of the wall, and the amount of snow erosion on the leeward side of the bridge deck is obviously smaller than that on the windward side, with the least erosion at the wake. The influence of snow on the third-part force coefficient of the main girder is greater, the absolute value of the lift coefficient and the torque coefficient increase by about 40%, and the absolute value of the drag coefficient increases by about 15%. Due to the action of snow, the vertical vortex induced vibration disappears at + 3 ° of the main girder, meanwhile the slope of the flutter derivative A * 4 curve changes from negative to positive and the effect of snow shape under different wind speeds is small. When dimensionless reduction The wind speed increases to a certain extent, H * 2 curve is relatively flat, while H * 4 remains unchanged.