Abstract Crystal plasticity (CP) models have been evolving since their inception. Advanced experimental characterization methods have contributed significantly to assess the performance and subsequent improvement of many empirical relations in CP, which were directly adopted from classical plasticity theories of solids at the macro-scale. In this research, high energy X-ray diffraction microscopy (HEDM) has been used to track the stress-state of individual grains within a polycrystalline aggregate of a Nickel-base superalloy subjected to cyclic loading. Using path-dependent, mesoscopic stress-states from the HEDM experiment, the performance of two kinematic hardening models, in the context of CP, has been assessed. One of the models is an empirical Armstrong-Frederick equation, and the other is a geometrically necessary dislocation (GND)-based phenomenological model. The results suggest that the GND-based model is capable of capturing the cyclic crystal plasticity response. The present validation efforts are expected to take CP models one step closer towards their implementation in modern engineering workflow.

中文翻译：

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使用高能 X 射线衍射显微镜实验和晶体塑性有限元模拟对背应力模型进行比较评估

摘要 晶体可塑性 (CP) 模型自诞生以来一直在不断发展。先进的实验表征方法对评估 CP 中许多经验关系的性能和随后的改进做出了重大贡献，这些关系直接从宏观尺度的固体经典塑性理论中采用。在这项研究中，高能 X 射线衍射显微镜 (HEDM) 已被用于跟踪受到循环载荷的镍基高温合金多晶聚集体中单个晶粒的应力状态。使用来自 HEDM 实验的路径相关的细观应力状态，评估了两个运动硬化模型在 CP 背景下的性能。其中一个模型是经验 Armstrong-Frederick 方程，另一个是基于几何必要位错（GND）的现象学模型。结果表明，基于 GND 的模型能够捕捉循环晶体塑性响应。目前的验证工作有望使 CP 模型更接近其在现代工程工作流程中的实施。