Finite element analyses of rolling contact fatigue crack initiation in railheads
Finite element analyses of rolling contact fatigue crack initiation in railheads
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DOI：
10.1243/0954409011531558
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发表时间：
2001-07
期刊：
影响因子：
--
通讯作者：
J. W. Ringsber;B. Josefson
中科院分区：
文献类型：
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作者：
J. W. Ringsber;B. Josefson
摘要研制了一种分析钢轨头部滚动接触疲劳裂纹萌生的有限元分析工具。该工具包含弹塑性非线性运动硬化材料模型，可以模拟棘轮衰减速率。有限元工具被应用于瑞典一个测试地点通勤列车交通中使用的钢轨。通过模拟不同的接触载荷，比较了两种滚动接触条件对疲劳裂纹萌生的影响。这两种情况分别是新制造的钢轨(赫兹分布)和已经服役16个月的钢轨(非赫兹分布)。提出了一种结合多轴疲劳模型和临界平面法的疲劳分析策略，并提出了一种考虑低周疲劳和棘轮损伤机制的损伤累积准则。结合双盘试验的二维有限元分析，用一组双盘数据对疲劳评估策略进行了验证，结果吻合良好。对有限元工具的结果进行的疲劳分析表明，在疲劳裂纹萌生位置、裂纹面角度和计算的车轮通道数方面，疲劳裂纹萌生位置与瑞典试验场的观测和测量结果吻合良好。协议对赫兹分布特别有利。
Abstract A finite element (FE) tool was developed for the analysis of rolling contact fatigue crack initiation in railheads. An elastic-plastic non-linear kinematic hardening material model is included in the tool, which can model decaying ratcheting rate. The FE tool was applied to rails used in commuter train traffic at a Swedish test site. Two rolling contact conditions were compared, with respect to fatigue crack initiation, by modelling the contact loads differently. The two conditions were newly manufactured rails (Hertzian distribution) and rails that have been in service for 16 months (non-Hertzian distribution). A strategy proposed for fatigue analysis comprises a critical plane approach used together with a multiaxial fatigue model; a damage accumulation rule is also proposed that takes into account low-cycle fatigue and ratcheting damage mechanisms. Together with a two-dimensional FE analysis of a twin disc test, the fatigue evaluation strategy was validated by a set of twin disc data with good agreement. A fatigue analysis of the results from the FE tool show good agreement with observations and measurements made at the Swedish test site with respect to position for fatigue crack initiation, angle of the crack plane and the calculated number of wheel passages to initiation of head checks. Agreement was particularly good for the Hertzian distribution.