列车运行频率的增加及速度的提高使铁路钢轨承受的负荷越来越大，从而导致钢轨因疲劳引起的损伤不断扩张，因此钢轨必须定期进行超声波探伤。中速及高速钢轨探伤设备基本都采用超声波轮式探头。在轮式探头中，各个探头的入射角是固定的。钢轨的内侧由于火车轮缘的磨损，会引起超声波折射角的变化，进而影响检测效果。采用模拟的方法分析了钢轨内侧磨损对超声波无损探伤的影响，分析了不同钢轨磨损程度下折射角的变换情况，可以看出在有磨损的时候，波束还会进行偏移，当磨损很严重时将导致全反射。该模拟为设计高效可靠的轮式探头提供了理论基础，从而提高了钢轨探伤的可靠性。

Under the circumstance of the skyrocketing energy cost, being the most efficient transportation method, railroad becomes the first choice for transferring people and commodities. At the same time, the increase of the train frequency and the running speed means more loads on the railroad and thus causes the growth of the fatigue crack of the railroad at more rapid rate. So the railroad has to be inspected periodically. Wheel probe is widely used in mid to high speed ultrasonic rail flaw detection equipment. In wheel probe, the incident angle is fixed. The wear of the rail of gauge side can cause the change of the refraction angle and thus affect the inspection results. The paper analyzed how the gauge side wear affected the inspection results, and tried to show how different level of gauge side wear changed the refraction angle. It was found that the gauge side wear could also cause the divergence of the beam. When gauge side wear was very severe, full reflection could occur. The simulation analysis presented in this paper can be used as the theoretical basis for design of effective and reliable wheel probe, thus improve the rail flaw detection capability.