目的 研究钢轨表面裂纹的扩展方向。 方法 采用有限元分析软件 ANSYS,在不同轴重和不同角度裂纹的工况下,获得不同裂纹位置的应力强度因子。 结果 裂纹在接触斑边缘的位置时,应力强度因子 K 最大。 随着轴重的增加,应力强度因子 K_I 和 K_II 均增大;随着裂纹角度的增加, K_I 增加,而 K_II 减小。 当裂纹角度为 60 ^o 时,其等效应力强度因子幅值 ΔK_eff 最大。 结论 钢轨表面的裂纹在扩展初期,以斜裂纹为主,扩展角度趋向于 60 ^o 。

Objective To analyze the propagation direction of rail surface crack. Methods The finite element method software ANSYS was used, and the stress intensity factors at the crack tip on rail surface were obtained for different locations of crack under conditions of different axle loads and crack angles. Results The stress intensity factor K was the maximum when the location of crack was at the edge of the contact area. The stress intensity factor K_I and K_II increased with the increase of axle load, while the stress intensity factor K_I increased and K_II decreased with the increase of crack angle. Conclusion The major rail surface crack was inclined crack at the initial stage of crack propagation and the propagation angle tended to be 60^o .