基于累积损伤的渗碳齿轮钢疲劳寿命预测模型构建

Fatiguelife prediction model of carburized gear steel based on cumulative damage

采用轴向高频疲劳试验机进行超高周疲劳实验,研究了不同应力比(R=0和R=0.3)下渗碳齿轮钢疲劳特性。结果表明:在应力比为0和0.3时,渗碳齿轮钢的失效形式分为表面失效和内部失效。内部失效过程分为疲劳裂纹萌生阶段(夹杂-细颗粒区(fine granular area,FGA))、稳定扩展阶段(FGA-鱼眼)和瞬间断裂(鱼眼之外)。基于累积损伤法,建立了内部裂纹萌生和扩展阶段的疲劳寿命预测模型;最终建立了渗碳齿轮钢多应力比下的全寿命预测模型,预测精度较高。

Very high cycle fatigue tests were carried out on the axial high-frequency fatigue testing machine.The fatigue characteristics of carburized gear steel under different stress ratios(R=0 and R=0.3)were studied.The results show that when the stress ratio is 0 and 0.3,the failure modes of carburized gear steel are divided into surface failure and interior failure.The interior failure process is divided into fatigue crack initiation stage(from inclusion to fine granular area(FGA)),stable propagation stage(from FGA to fisheye)and instantaneous fracture(outside fisheye).Based on the cumulative damage method,the life prediction models of interior crack initiation and propagation stages are established,respectively.Finally,the fatigue life prediction model of carburized gear steel is established,prediction accuracy is higher.