Design method of rail grinding target profile based on non-uniform rational B-spline

The grinding strategies for worn rails have a significant influence on the service life and maintenance cost of railways. Current grinding strategies, grinding the worn rails to their original profiles, leads to excessive amount of material removed and reduction of rail service life. Based on Non-Uniform Rational B-Spline theory (NURBS), which contributes to the control of curve smoothness, a rail profile reconstruction method was established considering the geometrical characteristics of the rail profile. The design of economical grinding rail profile can be achieved by using optimization method, which regards the amount of material removed and derailment coefficient as objectives, aiming at reducing rail wear. A new rail profile can be designed by integration of Archard wear model, FE contact model and vehicle-track coupling dynamic model. The result indicated that the wear of left and right rail is reduced by 29.26% and 31.06% compared with original CN60 profile, respectively. With the new rail profile, the dynamic performance is improved, and the contact stress, fatigue index and the amount of material removed is reduced. This optimized rail grinding profile contributes to the reduction of rail wear and guarantees the safety of train operation.