变摩擦系数条件下的轮轨滚动接触特性分析

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采用mixedLagrangian/Eulerian方法建立轮轨滚动接触有限元模型,在轮轨间使用与滑动速度相关的变摩擦系数定义切向接触属性,改变轮对角速度定义轮轨接触不同工况。在轮轨蠕滑工况下,通过对比取常系数摩擦系数和变摩擦系数的计算结果发现：变摩擦系数对轮轨滚动接触最大接触应力和接触斑面积影响较小;但是对轮轨接触斑内最大Mises应力、最大纵向切应力、最大横向切应力和蠕滑力影响较大,特别是对最大纵向切应力和蠕滑力影响幅度近20;对轮轨滚动接触蠕滑力矢量分布的影响也应值得注意。不同工况时轮轨蠕滑率不同,变摩擦系数条件下的轮轨蠕滑力和剪切应力随蠕滑率增大而增大,当轮轨间出现完全滑动时,轮轨蠕滑力达到极限。 The mixed Lagrangian/Eulerian method was used to establish the finite element model of wheel-rail rolling contact. The tangential contact properties were defined by variable friction coefficients related with slid- ing velocities between wheel and rail. Different operating conditions between wheel and rail were defined by changing the angular velocity of wheel. Comparing the analysis results using constant friction coefficients with those using variable friction coefficients in wheel-rail creeping conditions, it is found as follows. The friction co- efficients related with the sliding speed of wheel-rail rolling contact have little effect on the maximum contact stress and contact patch area; the variable friction coefficients have great impact on the maximum Mises stress, the maximum longitudinal shear stress,the maximum transverse shear stress and creep force in the wheel-rail contact patch,the influence may reach nearly 20% for the maximum longitudinal shear stress and creep force; vector distribution of wheel-rail rolling friction forces should be paid attention to; wheel-rail creep rates vary in different operating conditions; Creep forces and shear stresses increase with growing of creep rates under the condition of variable friction coefficients;the limit of wheel-rail creep forces is reached when fully sliding condi- tions occur between wheel and rail.