Fretting–fatigue behavior of steel wires in low cycle fatigue
Fretting–fatigue behavior of steel wires in low cycle fatigue
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DOI：
10.1016/j.matdes.2011.06.037
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发表时间：
2011-12
影响因子：
8.4
通讯作者：
Dagang Wang;Dekun Zhang;S. Ge
中科院分区：
文献类型：
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作者：
Dagang Wang;Dekun Zhang;S. Ge
利用能够施加恒定法向接触载荷的微动疲劳试验机，研究了应变幅对钢丝微动疲劳行为的影响。根据切向力与位移幅值的磁滞回线的形状确定微动状态。探讨了不同应变幅下，归一化切向力随循环次数和微动疲劳寿命的变化规律。采用扫描电镜和光学显微镜对钢丝微动疲劳试验后的微动接触痕形貌进行了观察，探讨了钢丝微动疲劳的失效机理。在微动疲劳试验中，采用声发射技术表征微动疲劳损伤。结果表明，在不同应变幅下，微动区均处于混合微动区。应变幅的增加增加了归一化切向力，降低了微动疲劳寿命。磨粒磨损、粘着磨损和疲劳磨损是不同应变幅下微动疲劳试验的主要磨损机制。拉伸钢丝微动疲劳过程中的累积声发射次数随着应变幅的增加而减少。应变幅的增加导致裂纹加速成核和扩展，从而降低寿命。
The effect of strain amplitude on fretting–fatigue behavior of steel wires in low cycle fatigue was investigated using a fretting–fatigue test rig which was capable of applying a constant normal contact load. The fretting regime was identified based on the shape of the hysteresis loop of tangential force versus displacement amplitude. The variations of the normalized tangential force with increasing cycle numbers and fretting–fatigue lives at different strain amplitudes were explored. The morphologies of fretting contact scars after fretting–fatigue tests were observed by scanning electron microscopy and optical microscopy to examine the failure mechanisms of steel wires. The acoustic emission technique was used to characterize the fretting–fatigue damage in the fretting–fatigue test. The results show that the fretting regimes are all located in mixed fretting regimes at different strain amplitudes. The increase in strain amplitude increases the normalized tangential force and decreases the fretting fatigue life. The abrasive wear, adhesive wear and fatigue wear are main wear mechanisms for all fretting–fatigue tests at different strain amplitudes. The accumulative total acoustic emission events during fretting–fatigue until fracture of the tensile steel wire decrease with increasing strain amplitude. An increase of the strain amplitude results in the accelerated crack nucleation and propagation and thereby the decreased life.