含异物击打伤高速动车组车轴疲劳寿命预测

Fatigue Life Prediction of High-Speed EMU Axle with Foreign Object Damage

基于高速动车组EA4T车轴疲劳小试样,采用正方体状钨钢弹丸高速冲击其表面,以模拟车轴表面异物击打伤;采用旋转弯曲疲劳试验方法进行光滑和缺陷试样疲劳性能试验;采用Abaqus软件,模拟分析缺陷附近区域的残余应力;构建基于疲劳指示参数(Fatigue Indicator Parameter,FIP)的缺陷小试样和含击打伤实物车轴疲劳寿命预测模型,并进行台架试验验证。结果表明:小试样疲劳寿命试验数据均在预测值的2倍线内,实物车轴疲劳寿命预测模型与车轴台架试验结果一致,小试样和实物车轴疲劳寿命模型预测结果准确;动车组动力车轴运用检修中深度小于1.0 mm的击打伤类缺陷可不做打磨或其他处理。

The defects were prefabricated on the small fatigue specimens of EA4T axle for high-speed EMU by the high-speed impact with the square shaped tungsten steel projectile to simulate the foreign object damage on the axle surface.The fatigue properties of smooth and defective specimens were studied by means of rotating bending fatigue test.The residual stress near the defect was simulated and analyzed by the Abaqus software.A fatigue life prediction model of small defect sample and the actual axle with impact damage was set up based on Fatigue Indicator Parameter(FIP)and verified by bench test.Results show that the fatigue life test data of small samples are within 2 times of the predicted value,and the fatigue life prediction model of the real axle is consistent with the results of axle bench test.As a result,the fatigue life prediction results of small sample and real axle are accurate.No grinding or other treatment is required for the impact defects with the depth less than 1 mm in the operation and maintenance of EMU power axle.