考虑微动磨损的钢丝微动疲劳裂纹扩展寿命预测研究

微动疲劳是矿井提升钢丝绳主要失效形式之一，在钢丝微动疲劳过程中，微动磨损严重影响钢丝微动疲劳裂纹扩展特性，进而制约钢丝微动疲劳断裂机制，故开展考虑微动磨损的钢丝微动疲劳裂纹扩展寿命预测研究至关重要. 运用自制钢丝微动疲劳试验机开展钢丝微动疲劳试验和拉伸断裂试验，通过高速度数码显微系统揭示微动疲劳过程中钢丝微动磨损演化、裂纹萌生和扩展及断裂特性，基于摩擦学和断裂力学理论，运用有限元法、循环迭代法和虚拟裂纹闭合技术建立了考虑微动磨损的钢丝微动疲劳裂纹扩展寿命预测模型，并进行试验验证. 结果表明:采用微动疲劳过程稳定阶段磨损系数预测钢丝微动磨损演化可保证预测正确性，微动疲劳过程中钢丝主要为I型裂纹扩展模式，考虑微动磨损的钢丝微动疲劳裂纹扩展寿命预测值和试验值吻合较好，验证了预测模型正确性. 

Prediction of Fretting Fatigue Crack Propagation Life of Steel Wire Considering Fretting Wear

Fretting fatigue is one of main failure modes of hoisting rope in coal mine. During fretting fatigue of steel wire, fretting wear seriously affects the fretting fatigue crack propagation characteristic of steel wire, and thereby restricts the fretting fatigue fracture mechanism of steel wire. Therefore, it is of great importance to carry out the research on prediction of fretting fatigue crack propagation life of steel wire considering fretting wear. Fretting fatigue and tensile fracture tests of steel wires were carried out by employing the self-made fretting fatigue test rig. Fretting wear evolution, crack initiation and propagation, and fracture characteristics of steel wire during fretting fatigue were revealed using the high-speed digital microscope system. The prediction model of fretting fatigue crack propagation life of steel wire considering fretting wear was established based on theories of tribology and fracture mechanics and applying the finite element method, iterative method and virtual crack closure technology, which was validated by fretting fatigue tests. The results showed that the prediction of fretting wear evolution of steel wire using the wear coefficient at the stabilized stage of fretting fatigue ensured the prediction accuracy. The mode I crack propagation was mainly present during fretting fatigue of steel wire. Predicted fretting fatigue crack propagation life of steel wire considering fretting wear was consistent with the experimental value, which validated the prediction model.