Simulation Analysis On Performance Of Curve Negotiation Of CRH2

In recent years,with the continuous development of railway technology,trains are gradually moving towards higher speeds,and the running performance requirements of vehicles are becoming higher and higher.Therefore,the dynamic performance between wheels and rails is an important factor related to driving safety.In particular,the curve passing performance of the vehicle not only affects the stability,comfort,operating efficiency and cost of the train,but also relates to the economic benefits and macro planning of the entire railway transportation.This research first introduces the theory of multi-body dynamics and vehicle dynamics.The CRH2 EMU trailer is taken as the research object,and the force elements are simplified with reference to its actual design parameters and structural characteristics.Based on the multi-body dynamics software UM,a reasonably simplified bogie and car body model is established,according to the design parameters of the high-speed railway,the tread shape and rail profile are added,the curve line parameters and track irregularities are set,and the vehicle-track coupling dynamic Learning model.Finally,the model is applied to analyze the influence of curve radius,curve superelevation,and relaxation curve length on various dynamic indexes under two different working conditions: under-elevation and over-elevation.At the same time,the comfort of the vehicle when passing through the curve was evaluated using the smoothness index.The various indicators are combined to obtain the optimal curve passing radius,super-high,gentle curve length and curve passing speed.Under the three curve conditions,the length and depth of the scar were used as variables to analyze the influence of the unilateral wheel scar and the two-sided wheel scar on the curve passing ability.The research results show that when the radius is the same under the ultra-high working conditions,all the dynamic indexes show an upward trend with the speed.When the speed is the same,the larger the radius of the curve,the smaller the value of each dynamic index.When the radius is the same under excessively high working conditions,the wheel-rail lateral force,the wheel lateral force,and the vehicle body lateral acceleration all decrease with speed.The larger the curve radius,the greater the value of each indicator.At the same speed,each dynamic index increases monotonically with the increase of superelevation.Under the same superelevation,the wheel load reduction rate and wheel-rail vertical force both increase with the increase of speed.Orbit lateral force decreases with increasing speed;When a train passes through a curve,flat scars on the wheels inside the curve have a greater effect on the curve passing performance;when flat scars appear on both sides of the wheelset,the phase difference has a certain effect on the curve passing performance.