Numerical Analysis of Wheel/Rail Adhesion Characteristics for Heavy Haul Train

A wheel/rail steady state rolling contact finite element model based on ALE(Arbitrary Lagrangian Eulerian) finite element method is developed.The model is applied to calculate and analyze the wheel/rail adhesion characteristics of heavy haul train,and also to study the influence of different running speed on the wheel/rail adhesion and creep characteristics.The model is used to analyze the process from braking,idle running to traction of wheels on track for heavy haul high power locomotive.The change law of wheel/rail contact state and the adhesion characteristic curve during this process are obtained.During braking,idle running and traction process of heavy haul high power locomotive,the longitudinal wheel/rail friction force changes gradually from opposite direction saturation state to traction direction saturation state.Whereas the lateral wheel/rail friction force always distributes anti-symmetrically and the location of its maximum value moves towards the center of the contact patch then gradually moves away from the center.During this process,the vector distribution of friction force changes gradually from the opposite motion direction to the same motion direction,and the friction force vector shows rotating distribution with the rotating center moves from wheel flange to the contact patch and then gradually to the side of wheel flange.Under low longitudinal wheel/rail creep rate situation(≤0.003),the adhesive force increases linearly with the increase of longitudinal creep rate while the running speed has no obvious impact.Under high creep rate situation(0.003),the adhesive force descends with the increase of creep rate,and higher speed will lead to faster descending of adhesive force.