ABSTRACT

Equivalent conicity is an equivalent mean parameter for reflecting the effects of lateral wheel-rail forces on passenger comfort on trains. Based on the asymmetry of the variable cross-section rails in the turnout zone, this paper views the equivalent conicity of a wheelset in the turnout zone as an equivalent conicity of a wheelset in which the wheels match all constant-section asymmetrical rails. A calculation method is established for the equivalent conicity of the turnout zone according to the hunting motion wavelength formula of wheelsets; considering the Rolling Radius Difference (RRD) curve of several ‘zero-crossings’, the principle of minimum gravitational stiffness is used as reference for determining the point ye at which the equivalent conicity of a large lateral displacement is calculated. For fluctuating RRD, the equivalent conicity is calculated using the zoning method; the paper also proposes to evaluate wheel-rail contact geometry in the turnout zone based on the nominal equivalent conicity of the most probable lateral displacement of the wheelsets. Using the matching of wheelsets of different service lengths and the No.18 turnout switch zone as an example, this paper studies the effects of a changing wheel profile on the equivalent conicity of the turnout zone.

摘要

等效锥度是反映侧向轮轨力对列车乘客舒适度影响的等效平均参数。基于道岔区变截面钢轨的不对称性，本文将道岔区轮对的等效锥度视为车轮与所有等截面非对称钢轨匹配的轮对等效锥度。根据轮对摆动运动波长公式，建立了转向区等效锥度的计算方法；考虑到几个“过零”的滚动半径差（RRD）曲线，以最小重力刚度原理为参考确定计算大横向位移等效锥度的点ye。对于波动的 RRD，等效锥度采用分区法计算；该论文还建议根据轮对最可能横向位移的标称等效锥度来评估道岔区的轮轨接触几何形状。以不同使用长度的轮对和18号道岔区的匹配为例，研究了轮型变化对道岔区等效锥度的影响。