地铁曲线段非对称轨底坡对轮轨匹配特性的影响

Influence of Asymmetric Rail Cants in Metro Curves on Wheel/Rail Matching Characteristics

基于轮轨接触几何关系和轮轨非赫兹滚动接触理论,分析地铁曲线段存在的非对称轨底坡对不同车轮型面下轮轨接触几何特性和接触力学特性的影响;采用SIMPACK软件,建立某B型地铁车辆动力学模型,基于USFD磨耗函数建立车轮磨耗预测模型,研究非对称轨底坡对3种车轮型面下车辆曲线通过性能和车轮磨耗的影响。结果表明:外轨轨底坡固定为1/40时,内轨轨底坡的增大使内轨侧轮轨接触点分布偏向名义滚动圆外侧,从而增大了滚动圆半径差,改善了车辆曲线通过性能,但对不同型面车轮的改善程度不同;内轨轨底坡的增大对外轨侧轮轨接触力学特性无明显影响,但对S1002和DIN5573型面车轮的内轨侧法向压应力有增大作用,且内轨轨底坡增至1/10时LM型面车轮的内轨侧法向压应力才明显增大;对于LM型面,外轨轨底坡为1/40、内轨轨底坡为1/20或1/10时可明显减缓轮缘磨耗,内轨轨底坡设置在1/20附近较合适;对于S1002和DIN5573型面,非对称轨底坡对轮缘磨耗的影响较小。

The influence of asymmetric rail cants in metro curves on wheel/rail contact geometry and contact mechanics characteristics was analysed for different wheel profiles based on wheel/rail contact geometry relationship and wheel/rail non-Hertzian rolling contact theory.A dynamics model of B-type metro vehicle was built with SIMPACK,and the wheel wear prediction model was developed based on USFD wear function,through which the influence of asymmetric rail cants on vehicle curving performance and wheel wear was investigated for three wheel profiles.The results show that with the outer rail cant fixed to 1/40,an increase of inner rail cant makes the distribution of wheel-rail contact points on the inner rail side more inclined to the outside of the nominal rolling circle,thus increasing the radius difference of the rolling circle and improving the vehicle curving performance.However,the improvement effect is different for different wheel profiles.The increase of inner rail cant has no obvious effect on the wheel/rail contact mechanical characteristics of outer rail side.It leads to the increase of the normal compressive stress on the inner rail side of S1002 and DIN5573 wheel profiles,while the normal compressive stress on the inner rail side of LM profile increases significantly only when the inner rail cant is increased to 1/10.For LM profile,the flange wear can be alleviated obviously with the outer rail cant of 1/40 and the inner rail cant of 1/20 or 1/10.It is appropriate to set the inner rail cant around 1/20.For S1002 and DIN5573 profiles,the asymmetric rail cants have only a little influence on wheel flange wear.