Generally, the equivalent conicity function (ECF) is denoted by equivalent conicity at 3mm (λ_3mm) and a Nonlinearity Parameter (NP). NP describes the nonlinearity of the ECF and its influence on a vehicle design is explored thoroughly, however, NP’s role in vehicle and track maintenance is not researched yet. This paper investigates the influence of track maintenance actions on vehicle dynamics with help of NP vs λ_3mm scatter plots of ECF database. The ECF database is constructed by combining measured worn wheel and rail profile pairs of the Swedish high-speed vehicle and rail network, respectively. The ECF database revealed an inverse relationship between λ_3mm and NP, i.e., NP is negative for larger λ_3mm values. The combination of negative NP and high λ_3mm causes reduction in the vehicle’s nonlinear critical speed and vehicle often exhibit the unstable running on the Swedish rail network. Thus, the occurrence of ECF with negative NP and high λ_3mm is undersirable and the undesirable ECF can be converted into desirable ECF by grinding the rail, which converts ECF’s into positive NP and low λ_3mm combinations. Thus, the NP parameter along with the λ_3mm must be considered in track maintenance decisions.

通常，等效锥度函数 (ECF) 由 3mm 处的等效锥度 (λ _3mm ) 和非线性参数 (NP) 表示。NP描述了ECF的非线性及其对车辆设计的影响进行了深入探讨，但是NP在车辆和轨道维护中的作用尚未研究。本文借助 ECF 数据库的 NP vs λ _3mm散点图研究了轨道维护动作对车辆动力学的影响。ECF 数据库是通过结合测量的瑞典高速车辆和铁路网络的磨损车轮和轨道轮廓对分别构建的。_{ECF 数据库揭示了 λ 3mm}与 NP之间的反比关系，即 NP 对较大的 λ _3mm为负价值观。负 NP 和高 λ _3mm的组合导致车辆的非线性临界速度降低，车辆在瑞典铁路网络上经常表现出不稳定的运行。因此，不希望出现具有负 NP 和高 λ _3mm 的 ECF，并且可以通过研磨钢轨将不希望的 ECF 转换为所需的 ECF，从而将 ECF 转换为正 NP 和低 λ _3mm的组合。因此，在轨道维护决策中必须考虑NP 参数和 λ _{3mm 。}