考虑摩擦因数与滑动速度相关时的轮轨滚动接触有限元分析

The Finite Element Analysis of Wheel/Rail Rolling Contact with Friction Coefficient Related with Sliding Speed

使用与滑动速度相关的摩擦因数替代库伦摩擦定律中的常系数,结合mixed Lagrangian/Eulerian方法建立轮轨滚动接触有限元模型,分析牵引力主导的蠕滑工况下的干燥状态的轮轨滚动接触特性。通过与摩擦因数取值为常数的轮轨滚动接触分析结果对比发现:与滑动速度相关的摩擦因数对轮轨滚动接触最大接触应力和接触斑面积影响不大,均在1%以内;但是对轮轨接触斑内最大Mises应力、最大纵向切应力、最大横向切应力和最大等效塑性应变影响较大,特别是对最大纵向切应力影响幅度近20%;更需要引起注意的是对轮轨滚动接触摩擦力矢量分布和切向塑性应变分布影响明显,这对轮轨滚动接触疲劳损伤分析非常重要。

Combined with mixed Lagrangiart/Eulerian method, the finite element model of wheel/rail rolling contact was established by using friction coefficient associated with sliding speed alternative to the constant in law of Coulomb friction. The characteristics of wheel/rail rolling contact in dry state of traction creep condition were analyzed. Compared with re- suits of finite element analysis in constant friction coefficient, it is found that the friction coefficient related with sliding speed of wheel-rail rolling contact has little effect on the maximum contact stress and contact patch area, which are less than 1%. But the varied friction coefficient has great impact on maximum Mises stress, the maximum longitudinal shear stress, the maximum transverse shear stress and maximum equivalent plastic strain in wheel/rail contact patch, especially on the maximum longitudinal shear stress by nearly 20%. It is very important to know that significantly diversification of tangential attention friction force vector distribution and plastic strain distribution of wheel/rail rolling for varied friction coefficient, which is basic data for damage analysis