钢丝微动疲劳裂纹萌生寿命预测研究*

钢丝微动疲劳过程中，钢丝裂纹萌生特性直接影响其裂纹扩展特性，进而制约钢丝微动疲劳寿命，因此开展钢丝微动疲劳裂纹萌生寿命预测研究具有重要意义。基于有限元法、摩擦学理论和断裂力学理论，运用Smith-Watson-Topper（SWT）多轴疲劳寿命准则建立考虑磨损的钢丝微动疲劳裂纹萌生寿命预测模型，基于多种不同的钢丝疲劳参数估算方法对钢丝的微动疲劳裂纹萌生寿命进行了预测，并探究接触载荷、疲劳载荷、交叉角度及钢丝直径等微动疲劳参数对钢丝微动疲劳裂纹萌生寿命的影响规律。结果表明：基于中值法的预测结果最接近实际值；在微动疲劳过程中，钢丝微动疲劳裂纹萌生寿命主要与接触载荷和疲劳载荷相关。通过引入微动损伤参数建立简化的适用于钢丝绳的钢丝微动疲劳裂纹萌生寿命预测模型，通过与考虑磨损的预测模型计算结果进行对比验证了该模型的准确性。

Prediction on Fretting Fatigue Crack Initiation Life of Steel Wire

In the process of steel wire fretting fatigue,the crack initiation characteristics of steel wire directly influence the crack propagation characteristics,affecting the fatigue life of steel wire fretting fatigue.Therefore,it is of great significance to carry out research on the prediction of fatigue crack initiation life of steel wire fretting fatigue.Based on the theory of fracture mechanics,finite element method and the tribology theory,the steel wire fretting fatigue crack initiation life prediction model considering the wear was established by using Smith-Watson-Topper (SWT) multiaxial fatigue life criterion.The fatigue crack initiation life of the wire was predicted based on a variety of wire fatigue parameters estimation method.The influence of fretting fatigue parameters such as contact load,fatigue load,cross angle and wire diameter on the initiation life of fretting fatigue cracks was investigated.The results show that the prediction results based on median method are the most close to the actual value,the initiation life of fretting fatigue cracks is mainly related to contact load and fatigue load.By introducing fretting damage parameters,a simplified fretting fatigue crack initiation life prediction model for steel wire rope was established.The accuracy of the model was verified by comparing with the calculation results of the prediction model considering wear.