接触角和横向载荷对轮轨粘着的影响

Effects of the Contact Angle and Lateral Load on the Wheel/rail Adhesion

应用多层多支子结构技术建立轮对与轨道的多体接触模型,采用参变量变分原理和数学二次规划法求解轮轨接触力,根据不同的接触角和横向载荷计算得出轮轨接触力分布,分析接触角和横向载荷对纵向摩擦力(牵引力)以及粘着系数的影响。计算结果表明,轮对承受横向载荷时,轮轨接触点对之间摩擦力的方向在粘着区和蠕滑区有明显的不同,在粘着区其方向与钢轨纵向夹角较小,而在蠕滑区其方向与钢轨纵向夹角较大;当接触角较小时,粘着系数随着横向载荷的增加而减小;当接触角较大时,随着横向载荷的增加,粘着系数先增加后减小;在直线段粘着系数随着轮对承受横向载荷的增加而减小,在曲线段选取适当的横向载荷能够提高粘着系数。

The multi-body contact model of wheel and rail is established with the technology of multilayer and multi-branch structure.The method of parameter variation principle and the mathematical quadratic programming is applied to solve the contact force.The distribution of wheel-rail contact force is computed under different contact angle and lateral load,and it is analyzed that the contact angle and lateral load effect on the longitudinal friction（traction） and adhesion coefficient.The results show as follows： The friction force direction in the wheel-rail contact is obvious different between the stick and the creep area,and in the stick area the angle between the friction direction and rails longitudinal is smaller,while in the creep area the angle is bigger.When the contact angle is smaller,the adhesion coefficient decreases with the lateral load increasing,and when the contact angle is bigger,the adhesion coefficient first decreases and then decreases with the lateral load increasing.The adhesion coefficient decreases with the lateral load increasing on the straight rail,and the adhesion coefficient can be improved by selecting proper lateral load on the curve rail.