流线型箱梁断面涡激力展向相关试验研究

Experimental Study on Spanwise Correlation of Vortex-excited Forces of a Streamlined Box Girder

针对闭口流线型主梁结构涡激力展向相关性问题,在均匀流场条件下分别对振动状态和静止状态流线型主梁节段模型进行了不同风攻角的涡激力展向相关性试验研究,分别分析了流线型主梁断面涡激振动响应、涡激力展向相关性及主梁表面压力等.结果表明:振动状态主梁断面涡激力展向相关系数与振幅、锁定区风速等相关,锁定区上升段主梁断面涡激力展向相关系数大于锁定区最大振幅处主梁断面涡激力展向相关系数,扭转涡振锁定区升力矩展向相关系数大于竖向涡振锁定区竖向涡激力展向相关系数;振动状态主梁断面测点压力系数展向相关系数与振幅相关,振幅越大则相关系数越大.

Aiming at spanwise correlation of vortex-induced forces （VIFs）of the main deck of bridges, wind tunnel experimens of an oscillating and stationary streamlined box girder were conducted under differ- ent wind attack angles in the smooth flow. The VIV responses, spanwise correlation of vortex-excited forces, and surface pressures of the streamlined box girder were investigated. The research results showed that the spanwise correlation coefficients of the vortex-excited forces of the streamlined box girder were re- lated to the amplitudes and wind speeds in the lock-in region. The spanwise correlation coefficients of the vortex-excited forces of the main deck at ascending stage of the lock-in region were larger than that of the main deck at the maximum amplitude of the lock-in region. The spanwise correlation coefficients of the pitch moments of the main deck in torsional VIV were larger than that of the lift forces of the main deck in vertical VIV. Meanwhile, the spanwise correlation coefficients of the pressures on measure points of the main deck were related to the amplitudes of the oscillating main deck, and the spanwise correlation coeffi- cients increased with the increase of the amplitudes.