面向钢轨砂带打磨的砂带磨耗过程建模

Abrasion Process Modeling of Abrasive Belt Grinding in Rail Maintenance

为揭示砂带服役寿命与打磨工艺参数之间的作用关系,针对钢轨砂带打磨中曲面、弹性接触特点,基于Archard方程和弹性赫兹接触理论,建立了面向钢轨砂带打磨的砂带磨耗过程模型.由数值仿真得到了不同接触压力、砂带速度、打磨列车速度、轨面曲率半径以及磨粒出刃高度均方差下的磨耗高度、砂带服役寿命曲线.并通过与现有砂带磨损试验结果对比,验证了模型的合理性.仿真分析结果表明:砂带表面磨耗轮廓线呈半椭球形,砂带寿命随接触压力、砂带速度的增加均呈指数形式降低,随打磨车速度增加呈近似线性增长;以60 kg/m钢轨为例,相同工艺条件下,打磨R13弧段较打磨R80、R300弧段时,砂带磨耗明显加剧;在钢轨表面粗糙度允许范围内,较大的磨粒出刃高度均方差有利于延长砂带的服役寿命.

Considering the contact area state under elastic contact of curved surfaces, an abrasive belt wear process model for rail grinding was established using the Archard equation and Hehzian contact theory to investigate the influence of technological parameters on the belt service life. The curves of wear height and belt service life were calculated through numerical simulations under different grinding forces, belt speeds, running car speeds, rail surface curvature radius and average variances of grit protrusion height. The rationality of the model was proved by comparing the simulational curves with existing experimental results. Simulation analysis illustrates that the wear contour of abrasive belt surface typically presents as a half ellipsoid, and the belt service life reduces exponentially with an increase in both the contact pressure and belt speed, but rise approximate linearly with the growth of running car speed. Taking the 60 kg/m rail as an example, under the same process conditions, the belt wear for grinding the R13 segment is clearly worse than that for both R80 and R300 segments. In the range of allowable rail surface roughness, a large grit protrusion height variance would be helpful to prolonging the abrasive belt service life.