线状多体系统定常气动力节段模型风洞测试

在风—车—桥耦合振动分析及具有独立式双层桥面的大跨桥梁风致振动分析中常需得到考虑相互气动影响的各构件的三分力系数。为进行线状多体系统定常气动力测试,在常规桥梁节段模型三分力测试装置的基础上研制了一种三分力分离装置———交叉滑槽系统。该系统利用环形滑槽和直线滑槽交叉点位置的变化来调整各测试构件间的相对几何关系,并能实现多构件的同轴转动,从而方便地进行不同迎角情况下的气动力的测试。最后,利用交叉滑槽系统对一具有双层桥面的钢管混凝土系杆拱桥在其上有车及无车情况下各构件的定常气动力进行了测试,试验结果表明:车辆的存在对上、下桥面的气动力有较明显的影响。

Section model wind tunnel test for steady aerodynamic force of line-like multi-body system

In both wind-vehicle-bridge coupling vibration analysis and wind-induced response of long double-deck bridge, it is necessary to measure steady aerodynamic force coefficient of each structural unit. In the test, aerodynamic influence among structural units is simulated. In order to measure steady aerodynamic force of line-like multi-body system, a separation device called Crossed Slot System is developed on basis of routine bridge section model measure device. In the device, geometrical relationship can be easily adjusted by the change of cross point between linear slot and circular slot. All structural units can be rotated around the same axis for the tests with various degree angle of incidence. Steady aerodynamic force of a concrete filled steel tube tied arch bridge with double decks is measured in various cases by Crossed Slot Sytem. It is showed that aerodynamic forces of super-deck and sub-deck can be significantly changed when a train is above the sub-deck.