研究目的：针对车轮与道岔钢轨磨耗严重的问题，以沪昆线湄池站为试验背景，现场测量其磨耗后LM 型车轮踏面与12号道岔钢轨型面，并基于迹线法原理和有限元理论求解车轮与道岔钢轨的接触问题，计算分 析轮轨型面磨耗对轮轨接触几何关系、接触应力、接触斑尺寸及内部应力的影响规律，为道岔钢轨廓形优化设 计及岔区钢轨打磨提供理论基础。 研究结论:( 1)轮轨型面磨耗改变了轮轨接触点对分布状态，缩短了岔区轮载过渡范围，增大了轮轨接触 竖向不平顺幅值及其波动程度，导致岔区轮轨相互作用增强，加剧了道岔钢轨的磨耗伤损；（2)轮轨磨耗能够 增加轮轨型面共形度，降低轮轨接触应力和Von Mises应力的幅值；（3)道岔钢轨Von Mises应力最大值一般 发生在距钢轨表面2. 7 ~4. 5 mm范围内，易导致此处接触疲劳裂纹的萌生；（4)本研究成果可供道岔钢轨廓 形优化设计时参考。

Research purposes :For the serious wear problems happened between wheel and switch rail， the actual profiles of worn LM type wheel and worn switch rail in the operating routes have been measured by the Shanghai Meichi station as test background. Based on the wheel - rail contact traces princij^le and finite element theory， the contact problem between wheel and switch rail was solved， and the effects of worn profiles on wheel and switch rail^s contact geometry relationship，contact stress， size of contact patch and Von Mises stress were analyzed， which provides the theoretical basis for the profiles optimization and grinding of switch rail. Research conclusions :( 1) Because of the worn profiles of wheel and switch rail，the distribution of wheel - rail contact points have been changed，the wheel load transition range has been shorten and the amplitude and fluctuation of wheel - rail contact vertical irregularity have been increased，which has increased the wheel - rail interaction and makes the wear damage more serious in turnout zone. (2) The wear can improve the contact comfort between the wheel and rail，and reduce the wheel - rail contact stress and Von Mises stress. (3) The maximum Von Mises stress of the switch rail occurs within the range from 2. 7 mm to 4. 5 mm under the rail surface， where the contact fatigue cracks can be easily generated. (4) The research results can provide the guidance for the profiles optimization of switch rail.