Abstract: The flange of wheels which are used in the urban railway wear severely. Aiming at this phenomenon, the wheel/rail contact is studied. Besides, there is big attack angle in the urban railway because of the small radius curves. So to study the influence of attack angle on the wheel/rail contact is important. The wheel profiles of the applied 70% low-floor vehicles and rail profiles are measured through the wheel/rail profile admeasuring apparatus. The elastic-plastic contact models with the measured wheel/rail profiles are calculated by the nonlinear finite element method when the wheel is under the effect of the lateral force and the driving torque. Through the calculation, the change laws of the Von Mises stress and the contact patches are analyzed at different working conditions and the influence of attack angle, lateral force and driving torque on the wheel/rail contact is studied. Some conclusions are indicated as follows. The shapes of wheel/rail contact patches with different attack angles are almost same. The patch shapes on the tread approximate rectangle and the ones on the flange are relatively long and narrow which can easily cause flange abrasion. With the attack angle increasing, the values that the position of flange contact patch is ahead of tread contact patch increase and the maximum equivalent Von Mises stress between wheel and rail increases gradually. The attrition power also increases. So when designing the wheel/rail profile match and vehicle structure, the attack angle should be kept within 1° as possible.

Key words: attack angle, contact patch, equivalent Von Mises stress, lateral force, wheel/rail contact