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采用ANSYS软件,仿真研究不同线路条件下轮轨接触位置变化对钢轨踏面斜裂纹扩展行为的影响。分析表明:轮轨接触位置沿纵向仅在距离钢轨踏面斜裂纹左右各1/4跨距范围内对斜裂纹扩展有突出影响,其余位置影响很小,可以忽略。在直线线路,当轮轨接触位置位于轨顶面中央时,钢轨踏面斜裂纹以Ⅰ-Ⅲ型的复合型方式扩展为主,扩展缓慢;偏离轨顶面中央5 mm时,钢轨踏面斜裂纹则以Ⅰ-Ⅱ型的复合型方式扩展为主,在踏面以下4 mm内可能发生水平转向,5.8~12 mm内容易发生横向转向。在800 m曲线线路外股,当轮轨接触位置偏离轨顶面中央16.5 mm时,钢轨踏面斜裂纹以Ⅰ-Ⅱ-Ⅲ型的复合型方式扩展为主,而且比直线线路扩展迅速;在踏面以下2.1~4.8 mm内,斜裂纹可能发生水平转向,而一旦扩展至更深位置时很可能会保持初始角度扩展下去。
ANSYS software is used to simulate the influence of wheel / rail contact position on the crack propagation behavior of rail tread under different conditions. The analysis shows that the wheel-rail contact position has a prominent influence on the oblique crack propagation in the longitudinal direction only in the range of 1/4 span from the left and right oblique cracks of the rail tread, and the rest positions have little influence and can be neglected. On the straight line, when the wheel-rail contact position is located at the center of the top of the rail, the oblique crack of the rail tread expands mainly to the complex type Ⅰ-Ⅲ and expands slowly. When the center of the rail top deviates 5 mm, the oblique crack of the rail tread The main type Ⅰ-Ⅱ complex expansion, the tread within 4 mm may occur within the horizontal steering, 5.8 ~ 12 mm prone to lateral steering. In the 800 m curve line, when the wheel-rail contact position deviates 16.5 mm from the center of the top of the rail, the inclined crack of the rail tread expands mainly in the complex type Ⅰ-Ⅱ-Ⅲ and expands more rapidly than the straight line. In the following 2.1 ~ 4.8 mm, oblique cracks may be horizontal steering, and once extended to a deeper position is likely to maintain the initial angle extended down.