Fretting fatigue often occurs in the interfaces between components, subjected to complex multi-axial load states and high stress gradients at the contact edge region. For the prediction of fretting fatigue crack initiation and in-depth understanding of the crack initiation mechanism, it is essential to investigate the damage mechanisms across various scales and explore the underlying scale coupling mechanisms. By introducing a power-law based scale coupling relationship, a two-scale model of fretting fatigue crack initiation life is proposed by combining macroscopic continuum damage mechanics (CDM) with microscopic crystal plastic finite element method (CPFEM). The simulation results indicate that the predicted fretting fatigue initiation life shows better accuracy than the result predicted by single-scale CDM model. In case of low stress level the rate of accumulated dissipation energy can be clearly divided into two stages with turning points, whereas it exhibits a relatively uniform damage process under high stress level. Moreover, the proposed two-scale model partly provides physical explanation for fretting fatigue crack initiation based on the information from the microscale.

中文翻译：

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累积晶体塑性耗散能驱动连续体损伤微动疲劳起始寿命的二维模型


微动疲劳通常发生在组件之间的界面中，受到复杂的多轴载荷状态和接触边缘区域的高应力梯度的影响。为了预测微动疲劳裂纹的萌生和深入了解裂纹的萌生机理，必须研究各种尺度的损伤机理并探索潜在的尺度耦合机制。通过引入基于幂律的尺度耦合关系，将宏观连续介质损伤力学 （CDM） 与微观晶体塑性有限元法 （CPFEM） 相结合，提出了微动疲劳裂纹萌生寿命的双尺度模型。仿真结果表明，预测的微动疲劳起始寿命比单尺度 CDM 模型预测的结果具有更好的精度。在低应力水平下，积累耗散能量的速率可以清楚地分为两个具有转折点的阶段，而在高应力水平下则表现出相对均匀的损伤过程。此外，所提出的双尺度模型基于微观尺度的信息部分地为微动疲劳裂纹的萌生提供了物理解释。