Research on the Control of Friction Coefficient of Inner and Outer Rails of Small Radius Curves in Subway

A subway train dynamics model is built using the multi-body dynamics software SIMPACK, taking the matching of inner and outer rail friction coefficients as the entry point and taking the wear index, derailment coefficient, and wheel-rail transverse force as the vehicle dynamics performance indexes. From two perspectives of different running speeds and loads, the influence of the subway curve line’s inner and outer rail friction coefficients on the vehicle dynamics performance is analyzed when it changes from 0.10 to 0.40. SPSSAU software was used to analyze the data, and the entropy weight method was applied to process the data to determine the weights of each index. Then, the relative proximity was derived by the TOPSIS method to determine the matching friction coefficients and the optimal friction coefficient matching intervals in each working condition. The influence of inner and outer rail friction coefficients on wear performance and curve performance under three speeds and three loads were analyzed respectively. Under the S1002 wheel profile, $60 \mathrm{~km} / \mathrm{h}$, and fully loaded working condition, the best friction coefficient matching is inner rail friction coefficient 0.10, outer rail friction coefficient 0.15. Adjusting the friction coefficient through the wheel-rail lubrication technology, the wear index, the transverse force, and the derailment coefficient were reduced by 23.93%, 34.45%, and 19.80% respectively.