Structural Performance Analysis Of Wind Barriers Under Coupling Of Transient Wind And Train Wind

Wind barriers are one of the main means to ensure the safety of high-speed trains in windy areas.The wind barriers along the railway are more complicated in the actual working environment: on the one hand,they are subjected to natural wind loads for a long time,and the direction of the load strength and the duration of the load are not fixed;on the other hand,the wind load of the train acts on the wind barrier in the form of an impact load when the high-speed train passes by.At present,in the design process of wind barriers,most of the crosswinds with constant wind speed are adopted,which cannot truly reflect the force of the wind barrier in the actual environment,which leads to large errors in the simulation results.In order to achieve more accurate calculation results from the simulation analysis of the wind barrier,it is necessary to analyze the aerodynamic response of the wind barrier under the coupling effect of sudden wind and train wind,and study the structural strength and fatigue strength of the wind barrier.In this paper,a three-dimensional aerodynamic simulation model of train-bridge-wind barrier coupling is established,and the aerodynamic response of the wind barrier under the coupling action of sudden wind and train wind is numerically simulated,and the pressure distribution law on the surface of the wind barrier is studied.With reference to the design standards,the solid structure model of the wind barrier was established,and the modal analysis of the wind barrier was carried out according to the theory of dynamics.The solid structure of the wind barrier was analyzed by the fluid-solid coupling method to analyze the wind barrier under different working conditions.Based on the stress and displacement distribution,the strength of the wind barrier is checked;according to the equivalent stress time history curve,the fatigue performance of the wind barrier is analyzed using the linear fatigue cumulative damage theory.The results show that:(1)The aerodynamic pressure on the surface of the wind barrier is positively correlated with the speed of the high-speed train,and negatively correlated with the distance between the wind barrier and the high-speed train.The higher speed of the high-speed train and the closer the wind barrier is to the high-speed train will lead to the greater aerodynamic pressure on the surface of the barrier;(2)The modal analysis of the solid structure model of the wind barrier found that the minimum natural frequency of the wind barrier is 6.11 Hz,and the natural frequency of the wind barrier is much different from the vibration frequency of the train wind.There is no resonance phenomenon;(3)In the coupled working condition of sudden wind and train wind,the effect of sudden wind plays a decisive role in the displacement and stress change of the wind barrier.In this working condition,the maximum Mises appears on the wind barrier.Therefore,it is of great significance to study the influence of sudden wind on the wind barrier;(4)In the fatigue analysis process of the overall solid structure of the wind barrier,the H-shaped steel column generates a large fatigue stress,which is the fatigue risk part of the wind barrier.The area of ? ? fatigue damage on the windward side of the barrier is larger,especially at the connection between the wind barrier and the bottom plate.In the actual engineering design,there are surface damage and stress concentration.This is the fatigue weakness.The wings on both sides of the web of the H-shaped steel column Although the slab fatigue stress is similar in magnitude,the direction is opposite.In the actual project,the design of wind barriers needs to consider the force characteristics of the H-shaped steel column.