近场动力学框架下钢轨疲劳裂纹萌生预测的数值方法研究

经典连续介质力学在求解由裂纹引起的不连续问题时，会出现数学构架失效的情况. 为克服这一难题，基于近场动力学理论，构建铁路钢轨疲劳裂纹萌生的数值预测方法，可实现钢轨疲劳裂纹萌生寿命与位置的预测. 当未出现疲劳裂纹时，通过与经典连续介质力学模型的结果对比，验证近场动力学模型的正确性和适用性. 分析了车轮全滑动、黏着-滑动和无摩擦三种状态对钢轨疲劳裂纹萌生的影响规律，结果表明：车轮由全滑动向无摩擦转变的过程中，裂纹萌生位置由钢轨表层转移到内部，裂纹萌生所需的荷载循环次数由0.45×107次增至2.05×107次，可见车轮滚滑状态会影响裂纹的萌生位置，并且较大的切向接触应力会显著降低钢轨的疲劳裂纹萌生寿命.

When solving discontinuous problems caused by cracks, classical continuum mechanics suffers from mathematical framework failure. To address this issue, a numerical prediction method for fatigue crack initiation in railway rails is developed based on the peridynamics theory, which can predict the initiation life and location of fatigue cracks in rails. When no fatigue cracks have formed, the correctness and applicability of the peridynamic model are verified by comparing with the results of classical continuum mechanics models. The influence rules of three wheel states, namely full sliding, stick-slip and frictionless, on fatigue crack initiation in rails are analyzed, and the results show that: As the wheel transitions from full sliding to frictionless state, the crack initiation location shifts from the rail surface to the interior, and the number of load cycles required for crack initiation increases from 0.45 × 10⁷ to 2.05 × 10⁷. It can be seen that the wheel rolling-sliding state affects the crack initiation location, and larger tangential contact stress significantly reduces the fatigue crack initiation life of railway rails.

搜集汇总

背景与挑战

背景概述

该数据集基于近场动力学理论，构建了铁路钢轨疲劳裂纹萌生的数值预测方法，研究了车轮滚滑状态对裂纹萌生位置和寿命的影响。结果表明，车轮滚滑状态变化会影响裂纹萌生位置，且较大的切向接触应力会显著降低钢轨的疲劳裂纹萌生寿命。