Abnormal wear analysis of straddle-type monorail vehicle running wheel tire

On the Chongqing's straddle-type monorail train in China, serious abnormal wear of running wheel tires occurs in its routine use, leading to a series of safety, environmental, and economic concerns. To analyze the causes of abnormal wear, a dynamic model of straddle-type monorail vehicle with full consideration to the lateral behavior of running wheel tire was established using Lagrange equations and verified by Zhong's model created using SIMPACK. Based on the boundary conditions provided in the dynamic model and the friction characteristics of tire and pavement, a finite element model of the running wheel tire was built and validated with vertical, lateral, and longitudinal stiffness tests of corresponding tires. The wear situations of each running wheel tire under extreme turning condition were described in detail with the contact behavior and an assessment was done based on the friction work and the friction work skewness value. Besides, the influence of slip angle, roll angle, and their combined effect on the abnormal wear of running wheel tire was analyzed. This research proposes that, reasonable matching of the slip angle and the roll angle is of engineering significance and it can reduce uneven wear of the running wheel tire.