长大坡道低黏着环境下轮轨动态相互作用研究OA

Adverse weather conditions such as rain and snow lead to low-adhesion conditions,which directly impact the stability and safety of vehicle operation on long steep slopes.To investigate the operational stability of vehicles under low-adhesion conditions on long steep slopes,a vehicle-track coupled dynamic model incorporating traction acceleration behavior was first established.The adhesion coefficient formula varying with speed was fitted based on experimental data to simulate vehicle traction acceleration behavior under low-adhesion conditions on long steep slopes.Subsequently,based on this model,a time-domain excitation method was employed to compare and analyze the dynamic wheel-rail interactions under low-adhesion conditions on long steep slopes and to explore the effects of three factors on vehicle operational stability:traction load magnitude,track irregularities,and slope gradient.The study reveals that:(1)under a traction load of 100 kN,when accelerating on a 10‰ gradient under low-adhesion conditions,the wheel-rail lateral displacement,wheel-rail normal force,and longitudinal force all gradually deviated from their equilibrium positions with increasing speed,ultimately resulting in instability.Compared to a flat track,the vehicle instability speed occurred approximately 8 km/h earlier on a 10‰ gradient.(2)The magnitude of the traction load,track irregularities,and slope gradient all affected vehicle stability.As the traction load increased,the slope gradient increased,and track irregularities were introduced,the vehicle instability speed occurred earlier.