钢轨疲劳裂纹萌生与磨耗发展共存预测中的 磨耗阈值

Effect of Wear Threshold on Prediction for Rolling Contact Fatigue Crack Initiation and Wear Growth of Rail

摘要:

提出了等磨耗深度与等车轮通过次数两种不同的磨耗阈值确定方法，分析了磨耗阈值对钢轨型面、磨耗发展率、疲劳损伤、裂纹萌生位置和寿命等预测的影响。结果表明：不同的磨耗阈值下，三次插值样条曲线平滑处理磨耗型面时引起的误差可以忽略；磨耗阈值对平均磨耗发展率影响不大，但对疲劳损伤及其发展影响明显；磨耗阈值较小时，如磨耗深度h≤0.04 mm或车轮通过次数t≤3.0×10⁴，预测的裂纹萌生位置、裂纹萌生寿命基本接近，计算效率略低；磨耗阈值较大时，相比阈值较小的结果，裂纹萌生位置有小于5.0%的偏差，裂纹萌生寿命最大有13.5%的偏差，计算效率提高50%~60%。

Abstract:

The determination of wear thresholds by the methods of wear vertical depth and wheel cycles was presented. The effect of wear thresholds on the prediction of rail profile, wear growth rate, fatigue damage, crack initiaiton position and life was analyzed. The results show that the error by the cubic interpolation spline with different wear thresholds to smooth rail profiles can be ignored. The wear thresholds have little effect on the average wear growth rate and an obvious impact on the fatigue damage. With small wear thresholds, such as the wear depth h≤0.04 mm or the wheel cycles t≤3.0×10⁴, the predicted crack initiation position and life is close to each other. The simulation efficiency is slightly lower. Compared with the results at smaller wear thresholds, the predicted crack initiation position at larger wear thresholds has a deviation of less than 5.0%. The crack initiation life has a maximum deviation of 13.5%. And the simulation efficiency is increased by 50%~60%.