针对过盈配合的连杆小头和衬套之间存在的微动疲劳现象,建立连杆有限元模型,用ANSYS软件对其进行微动疲劳仿真,提取并分析连杆-衬套接触区上的应力、位移数据,分别用RUIZ综合参数法、MSR临界面法、基于损伤力学的热力学耗散势函数法预测衬套微动裂纹萌生位置.结果表明,3种方法预测的裂纹萌生位置保持一致,即衬套接触边缘内侧最易萌生微动裂纹.用方足桥-试件模拟件进行微动疲劳实验验证.结果表明,3种方法预测位置与实验试件断裂位置保持一致,其中基于热力学势函数法预测结果最为准确.%Aimed at the fretting fatigue phenomenon existed between the connecting rod and bushing interference fit,the finite element model of connecting rod was established,and the fretting fatigue simulation was conducted with ANSYS.The stress and displacement distribution on the contact surface of the connecting rod-bushing was extracted and analyzed,and the fretting crack initiation location of bushing was predicted by using RUIZ comprehensive parameter method,MSR critical surface method and the thermodynamic dissipation potential function method respectively.Results show that the predicted crack initiation location with three methods is very close,that is,the inner side of the bush edge is the most easy to crack.The fretting fatigue tests were carried out with the simulated specimens and the square foot bridge.Results show that the predicted location is consistent with the experimental data,and the prediction results based on the thermodynamic potential function method is the most accurate.
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