箱梁表面的压力分布对颤振稳定性的影响EI北大核心CSCD

该文建立了箱梁表面压力与颤振导数之间的数学关系,探讨了表面压力的分布特性对箱梁颤振导数和颤振临界风速的影响。结合流固松耦合的计算方法,利用动网格技术模拟了箱梁的风致振动。采用分块分析方法研究了箱梁表面压力的局部特性对颤振导数以及系统振动能量的影响。研究结果表明:箱梁迎风侧风嘴附近的分布压力对模型振动的稳定性产生了不利的影响,而模型尾部的压力则有助于提高系统的颤振临界风速。当迎风侧的分布压力向模型尾部移动时,对箱梁颤振稳定性影响较大的颤振导数则会发生较显著的变化,箱梁的颤振临界风速也随之增加,因此断面迎风侧风嘴附近区域的分布压力对颤振导数和系统振动的稳定性影响最大。另外,迎风侧风嘴附近的区域也是振动系统吸收气动能量的主要部位,而箱梁尾部风嘴附近的区域则消耗系统的振动能量。箱梁表面压力与模型振动最大位移之间的相位差对颤振导数有较大影响,当相位差沿断面呈反对称分布,并使气动阻尼始终为负时,则有利于箱梁颤振的稳定性。

THE INFLUENCE OF BOX GIRDER SURFACE PRESSURE DISTRIBUTION ON FLUTTER STABILITY

The relationship between box girder surface pressure and flutter derivatives was established. Based on qualitative and quantitative analyses, the influences of the pressure distribution along box girder on aerodynamic derivatives and flutter critical wind speed were discussed. Combined with fluid-structure loose coupling calculation method, the wind-induced vibration of the box girder was simulated by dynamic grid technique. The effects of pressure local characteristics on box girders’ main flutter derivatives and system vibration energy were investigated by using the block analysis method. The results show that the distribution pressures near the wind fairing on the model windward side are not conducive to box girder flutter stability, but the pressures on the model tail are helpful to improve the flutter critical wind speed. When the distribution pressure on box girder windward side moves to the model tail, the aerodynamic derivatives, which have a great influence on box girder flutter, have great changes, and the box girder flutter critical wind speed also increases. The local characteristics of pressures on the model windward side wind fairing have the greatest influence on flutter derivatives and system vibration stability. The aerodynamic force near the model windward side region transfers energy to the vibration system, while that near the model leeward side consumes system energy. The phase lag between the pressure and the model maximum displacement also has a great influence on flutter derivatives. When the phase lag along the model surface is antisymmetric and the aerodynamic damping force is always negative, it has a beneficial effect on system vibration stability.