Influence Of Wind Barrier On Aerodynamic Characteristics And Running Safety Of Moving High-speed Trains On Bridges

The safety of train operation on bridge in the wind environment is becoming increasingly prominent,due to the complex distribution of wind area in China,the construction characteristics of "replacing road with bridge" and the lightweight and high-speed design of modern high-speed train.The safety and comfort of high-speed train in the wind environment can be improved by setting wind barriers.In this thesis,high-speed train is taken as the research object,then the influence rules of wind barrier on the aerodynamic characteristics and running safety of the vehicle is studied through moving train wind tunnel test system and wind-train-bridge coupling vibration analysis.It includes the following aspects:(1)The wind tunnel test of the wind barrier-moving train-bridge system model was carried out,and the test system was described and evaluated in detail from the aspects of system composition,test conditions and test stability.According to the test wind speed,vehicle speed,lane position,air permeability of wind barrier,the aerodynamic force of moving train was measured under different working conditions.The lowpass filtering method was used to remove the interference components from the test results,and the stability of the test system is well.(2)The aerodynamic characteristics of the train under different working conditions were analyzed by data processing.The differences between the aerodynamic characteristics of dynamic and static models were analyzed.The effects of vehicle speed,wind speed,yaw angle lane position and wind barrier parameter on the aerodynamic characteristics of the train were studied.The results show that the aerodynamic characteristics of the train in the dynamic and static model are quite different,and the change of the vehicle speed,wind speed,yaw angle,lane position and wind barrier parameter have different degrees of influence on the aerodynamic characteristics of the train inside and outside the barrier.(3)Based on multi-body dynamic and mode superposition method,a simplified windtrain-bridge coupling vibration model was established.The dynamic responses of train with different air permeability of wind barrier,yaw angle and line position were calculated.The influence of various parameters on running safety of the train is analyzed,and the windpreventing effect of the barrier was evaluated.The results show that the wind barriers with air permeability of 15% and 30% have satisfying wind-preventing effect,and the yaw angle of the moving train has a significant impact on the effect of the barrier.The wind barrier has well wind-preventing effect on the lanes of windward and leeward side.The amelioration of the dynamic response of the trains on the windward side is more obvious.