高速列车轮轴压装部位微动疲劳损伤行为及寿命预测方法研究

When the vehicle is in motion,cycling fretting will occur in the press-fitted section edge of the axle under rotary bending stress. The fretting wear and multi-axial stress in the slip section of the press-fitted will cause the fretting fatigue of the axle. In this study the fatigue tests will be carried out with the press-fitted axle sample. According to the experimental condition, the elastic-plastic finite element model is established. The fretting wear model of the press-fitted structure is constructed by applying the ARCHARD modified equation and ABAQUS program. The crack initiation is defined according to the degree of cumulative cycle damage. Based on the fretting wear model and critical plane SWT parameter method for multi-axial fatigue, the fretting fatigue crack initiation evaluation method for press-fitted axle sample is established. The evaluation method is optimized by comparing the test results with the evaluated results. According to the optimized fatigue life evaluation method, the influence of the interference magnitude, wheel hub dimention and wheel hub overhang on the fretting fatigue damage and crack initiation life for press-fitted section of the high speed railway wheel/axle is investigated.The fatigue life evaluation method proposed in this study can supply the scientific basis for the damage analysis, fatigue life evaluation, design and manufacture specification for the high speed train axle.

列车运行过程中，在旋转弯曲应力作用下，车轴压装面的两端相对于轮毂发生循环往复微动，压装滑移区的微动磨损和多轴应力将不可避免的引起车轴的微动疲劳破坏。本项目开展压装车轴试样的疲劳试验。按照试验条件，建立压装车轴试样的弹塑性有限元模型，使用ARCHARD修正方程，结合ABAQUS程序，建立压装结构的微动磨损模型。以累积循环损伤程度作为裂纹萌生判据，将微动磨损模型与多轴疲劳临界面SWT参数法相结合，建立压装车轴试样的微动疲劳裂纹萌生寿命预测方法。比较试验结果与寿命预测结果的共性和差异，优化预测方法。使用优化后的寿命预测方法，研究压装过盈量、轮毂尺寸以及轮毂悬突等条件的变化对高速轮轴压装部位的微动疲劳损伤程度及裂纹萌生寿命的影响。本项目提出的寿命预测方法，可为高速列车车轴的优化设计、损伤分析、寿命预测以及设计和制造规范的制定提供科学依据。

完成了小尺寸过盈配合结构微动疲劳中断实验，观察和测量了配合面磨损轮廓和裂纹萌生随循环周次的演化过程，基于该小尺寸过盈配合结构建立了微动磨损定量仿真模型，实现了对过盈配合结构配合面磨损轮廓的仿真，在该微动磨损模型的基础上，结合多轴疲劳临界平面法（SWT参数法）与线性累积损伤模型（Miner法则）建立了过盈配合结构的微动疲劳裂纹萌生寿命预测模型，该模型能够较为准确的对微动疲劳裂纹萌生寿命和萌生位置进行预测，且较为合理的阐明了过盈配合结构微动磨损对微动疲劳萌生的影响。本项目通过对该模型的修正使其成功的应用于实验轮轴，实现了对轮轴压装部位卸荷槽形状、过盈量以及悬突量的优化。