Research On The Influence Of Train Induced Wind On The Overhead Transmission Tower-line Structure

The running of the train will cause the air flow around the car body to form an unsteady flow field.This kind of air flow generated by the movement of the train is called the train wind.When the train passes the adjacent structure of the railway,the train wind will exert a force on the adjacent structure.,Thus causing structural vibration,the problem of the vibration of the adjacent railway structure caused by train wind has always been one of the main research contents of high-speed train aerodynamics workers in various countries.High-voltage transmission lines are typical railway adjacent structures across high-speed railways.The influence of train wind on the overhead transmission tower-line structure is not clear.The structure of overhead transmission tower-line structure is a flexible structure and is susceptible to external wind loads.Wind loads may cause damage to overhead transmission tower-line structure and affect the normal operation of high-speed trains.Therefore,it is of great engineering significance to study the influence of train wind on the structure of overhead transmission tower-line across high-speed railways.This paper takes the phenomenon that the transmission tower-line structure crosses the high-speed railway as the research background,selects the CRH2 C highspeed train and 220 k V transmission tower-line structure as the research objects,and uses the numerical simulation method to make a detailed analysis of the train windinduced response of the overhead transmission tower-line structure.The force characteristics of the transmission lines and the dynamic response characteristics of transmission tower-line structure under the action of the train wind load,and the analysis of the influence of different train speeds and different transmission line parameters on the transmission-tower line structure subjected to the train wind load and the train wind induced dynamic response,Based on the analysis results,suggestions for the design of the overhead transmission tower-line structure considering the wind effect of the train are put forward.The analysis results put forward suggestions for the design of overhead transmission tower-line structure considering the train induced air flow.The main research content and conclusions in the article are as follows:(1)The fluid mechanics software STAR-CCM+ was used to establish a high-speed train transmission line fluid numerical model,and the accuracy of the numerical model was verified by comparison with test data.Variation characteristics of train wind load on transmission lines under the conditions of train running speed and different height differences across transmission lines.The results show that the train wind load on the transmission line segment directly above the track center is the largest,and the train wind load on the conductors on both sides of the track is symmetrical along the track center plane,and decreases toward both sides of the track with the symmetry plane as the boundary.The wind load on the transmission line segment at 15 m is close to 0 N;the train wind load on the transmission line increases with the increase of the train speed,and gradually decreases with the increase of the span height difference and the attenuation rate slowing shrieking.(2)The finite element model of 220 k V transmission tower-line structure was established using ANSYS finite element software.The accuracy of the model was verified by comparison with theoretical data,and the wind-induced vibration response characteristics of trains at different positions of the transmission tower line structure and the characteristics of the train’s wind-induced vibration response at different speeds and speeds were analyzed.Dynamic response characteristics under different span height differences and different transmission line spans.The results show that the dynamic response characteristics at different positions of the transmission tower-line structure under the action of train wind load are different.The transmission line part is mainly characterized by low-frequency vibration.The transmission tower part presents high-frequency vibration characteristics.The wind-induced vibration response of the train of the transmission tower line structure will increase with the increase of the train running speed.The displacement and dynamic tension amplitude of the transmission wire are linear with the train running speed.Positive correlation;with the increase of the transmission line span,the displacement of the transmission wire and the amplitude of the dynamic tension gradually decrease,and the change is roughly linear;within the range of 9m-15 m of the span height,the displacement of the transmission wire,The dynamic tension amplitude decreases with the increase of the span height difference.By increasing the span height difference,the dynamic response of the tower line structure can be significantly reduced.(3)According to the current wind load design code for high-voltage transmission lines,the difference in wind load on transmission lines with or without high-speed trains across is analyzed,and the values of wind load on transmission lines in the current specifications are revised and supplemented.According to the analysis results,it is recommended to cross-high-speed railway lines.For transmission lines,multiply by a wind load increase factor of not less than 1.1 when calculating the wind load on the transmission line.