CN1/18道岔辙叉轨件力学响应特征及裂纹整治方法

Mechanical Response Characteristics and Crack Treatment Methods of CN1/18 Turnout Frog Rail Components

针对CN系列道岔在不利条件下可能出现的心轨、翼轨及叉跟尖轨伤损等问题,建立CN1/18道岔辙叉轨件有限元模型,计算分析其力学响应特征;采用容许应力法分析验证病害产生原因,根据轨件受力状态提出了相应整治措施。结果表明:心轨和叉跟尖轨薄弱断面应力较大,有加工缺陷或划痕硌伤的条件下可能出现应力集中;准静态荷载作用下,翼轨强度满足要求,但安全余量较小,在长期服役条件下可能由于外部环境变化出现钢轨伤损,导致裂纹萌生和断裂。对于心轨,应加强凸缘和轨底交角位置的目视检查和涡流探伤,及时开展人工打磨整治或换轨处理;对于翼轨,应及时开展专项探伤,做好内倾的检查和调整;对于叉跟尖轨,应及时开展磁粉探伤,发现裂纹时须进行换轨处理。

A finite element model of the CN1/18 turnout frog rail component was established to address the potential issues such as damage of the center rail,wing rail,and fork heel switch rail of CN series turnouts under unfavorable conditions.The mechanical response characteristics were calculated and analyzed,and the allowable stress method was used to analyze and verify the causes of the diseases.Corresponding treatment measures were proposed based on the stress state of the rail components.The results indicate that the weak sections of the center rail and fork heel switch rail have high stress,and stress concentration may occur under conditions of processing defects or scratches and abrasions.Under quasi-static loading,the strength of the wing rail meets the requirements,but the safety margin is small.Under long-term service conditions,rail damage may occur due to external environmental changes,leading to crack initiation and fracture.For center rails,visual inspection and eddy flaw detection of the intersection angle between the flange and the rail bottom should be strengthened,and manual polishing or rail replacement should be carried out in a timely manner.For wing rails,special flaw detection should be carried out in a timely manner to check and adjust the internal inclination.For fork heel pointed rails,magnetic particle flaw detection should be carried out in a timely manner,and rail replacement should be carried out when cracks are found.