Analysis Of The Influence Of Different Wind Fields On The Lateral Stability Of Trains On Viaducts

Compared with flat line,when the wind force on the train running on viaduct,the superposition of bridge height and wind field makes the aerodynamic characteristics of the train obviously worse and the impact on the safety of the train is more prominent.The coupling effect of train wind and unsteady lateral wind makes the aerodynamic characteristics of the train different from the results of the pure crosswind under different operating conditions.In order to provide a comprehensive and reliable reference for the high-speed trains running on the bridge under different wind fields,it is necessary to analyze the aerodynamic characteristics and safety of the high-speed trains running on the viaduct in different wind fields.Establish an aerodynamic model based on a certain type of high-speed train.Based on the Chinese hat abrupt wind model,smooth transition gusts and sinusoidal gust models,the local dynamic layer change method is used to simulate and analyze single trains,parallel trains and rendezvous trains on the bridge,the aerodynamic characteristics of trains in different operating conditions in different wind fields are studied.Use SIMPACK to establish a dynamic model,analyze the safety indicators of trains in different operating conditions under different wind fields.The results show that:(1)compared with the influence of other wind fields on the aerodynamic characteristics of the train,the sinusoidal gust has a greater influence on the lift of the tail car of a single train and the tail car of the leeward side train in the meeting condition,which are 25.81 times and 1.95 times of the corresponding values under the gentle transition gust respectively,with the largest increase.(2)The pressure on the windward side of the middle car is the first in the head,middle and tail cars,and the pressure on the windward side of single train,parallel train and passing train under sinusoidal gust is higher than that of other wind fields.Due to the influence of coda wave and wind field,the windward side pressure of the middle car of the windward side train reaches the maximum of 540 Pa under the condition of sinusoidal gust.(3)Compared with the abrupt wind and sinusoidal gust,the vortex on the leeward side of the tail car is the largest in the three train operation conditions under the gentle transition gust,which is particularly significant in the train on the leeward side,which is especially significant in the parallel and meeting conditions.(4)When the two trains meet completely,the safety factor of the leeward wheel of the train increases and the train safety decreases under the gentle transition gust due to the influence of the pressure wave and the lateral action of the high wind speed wind field.The ratios of the vertical force,lateral force and derailment coefficient to the corresponding values under the sudden wind are 1.24,4.02 and 3.24.(5)The influence of wind field on train overturning coefficient is different due to different train operation conditions.The overturning coefficient of leeward side train in parallel condition is affected by the maximum acceleration of sinusoidal gust,which is 9.09 times of that of windward side train in 0.9 s.For the meeting conditions,the superposition of the wake and wind speed at the end of the rendezvous makes the overturn coefficient of the leeward train in the meeting conditions under sinusoidal gusts is6.14 times that of the windward train at 1.95 s.