上海卢浦大桥抖振时域分析

Time Domain Analysis of Buffeting on Shanghai Lupu Bridge

用抖振时域方法对上海卢浦大桥进行了抖振计算,并与全桥气弹模型风洞试验抖振位移相互比较分析,探讨了自激力和气动导纳等因素对抖振响应的影响。气动导纳采用实测值、Sears函数和1三种不同形式,抖振位移有明显差别。全桥气弹模型试验抖振位移与采用实测气动导纳的结果很接近。气动导纳为1时的抖振位移最大,Sears函数抖振位移最小。考虑18个气动导数比不考虑侧向气动导数得到的抖振位移要略小。自激力总体上会减小抖振位移,但幅度不大,工程计算中可以偏安全地忽略自激力的影响。

Buffeting response of Shanghai Lupu bridge was calculated in the time domain,and compared with the result of full-bridge aeroelastic model wind tunnel test. The influences of self-excited force and aerodynamic admittances on buffeting response were discussed. The buffeting displacement results based on aerodynamic admittances with measured values, Sears function and one are different one to another. The buffeting displacement of measured aerodynamic admittance is closer to the result of full-bridge aeroelastic model test. The largest buffeting displacement is the result of measured aerodynamic admittances in three different forms, whereas ,the least buffeting displacement is the result of aerodynamic admittances with Sears function. The buffeting displacement with consideration of flutter derivatives slightly is smaller than the buffeting displacement without consideration of lateral aerodynamic derivatives. The self-excited forces basically reduce buffeting displacement, but with small portion. The impacts of the self-excited forces can be neglected on the conservative side.