This study focused on understanding the fatigue response of anisotropic spherulitic polymers by employing a multiscale microscopic modeling approach. The crystal plasticity model together with the Arruda-Boyce model were used to describe the mechanical response of crystalline phase and amorphous. The fatigue behaviors and crack initiation were captured by Fatemi-Socie multiaxial criterion and continuous damage theory under multiaxial and non-proportional loading conditions. The sheaf-like structure of spherulitic polymers was considered to shed light on the anisotropic nature of fatigue failure. The results highlight the role of features of sheaf structure, e.g., initiation orientation, on the fatigue performance of spherulitic polymers, which have not been reported. The localized degradation of mechanical properties and the accumulation of fatigue damage were systematically discussed with various loading patterns. This study provided an in-depth understanding of potential fatigue mechanisms, offering robust support for fatigue resistance design in engineering applications.

中文翻译：

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球晶聚合物在多轴和非比例疲劳裂纹成核中的微观力学分析


本研究的重点是通过采用多尺度微观建模方法了解各向异性球晶聚合物的疲劳响应。晶体塑性模型与 Arruda-Boyce 模型一起用于描述晶相和非晶态的机械响应。采用 Fatemi-Socie 多轴准则和连续损伤理论捕获了多轴和非比例载荷条件下的疲劳行为和裂纹萌生。球晶聚合物的捆状结构被认为揭示了疲劳失效的各向异性性质。结果突出了捆结构特征（例如起始取向）对球晶聚合物疲劳性能的影响，这些特征尚未报道。系统讨论了机械性能的局部退化和疲劳损伤的积累与各种加载模式。本研究为潜在的疲劳机理提供了深入的理解，为工程应用中的抗疲劳设计提供了强有力的支持。