This paper presents an application to metal matrix composites (MMCs) of an enhanced elasto-viscoplastic Fast Fourier Transform (EVP-FFT) formulation coupled with a phenomenological continuum Mesoscale Field Dislocation Mechanics (MFDM) theory. Contrary to conventional crystal plasticity, which only accounts for plastic flow and hardening induced by statistically stored dislocations (SSDs), MFDM-EVP-FFT also describes the evolution of polarized geometrically necessary dislocation (GND) density and its effect on both plastic flow and hardening. Numerical results for a Fe–TiB2 MMC made of a ferrite matrix (α-Fe) and elastic ceramic particles (TiB2) are presented. Full-field simulations are performed using synthetic periodic unit cells representative of the MMC, with single-crystalline and polycrystalline matrix, for different particle interspacing distances. A strong dependence of the predicted equivalent stress, cumulated plastic strain and GND density fields with particle interspacing distance is observed, in contrast with conventional crystal plasticity. Correlations between these mechanical fields and microstructural features, and their influence on local and global mechanical behavior are examined for the different MMC microstructures.

中文翻译：

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基于基于FFT的介观场错力学，颗粒间距对Fe–TiB ₂金属基复合材料力学行为的影响

本文介绍了一种增强的弹黏粘快速傅里叶变换（EVP-FFT）公式结合现象学连续谱中尺度场错力学（MFDM）理论在金属基复合材料（MMC）中的应用。MFDM-EVP-FFT与传统的晶体可塑性相反，后者仅考虑由统计存储的位错（SSD）引起的塑性流动和硬化，MFDM-EVP-FFT还描述了极化几何必要位错（GND）密度的演变及其对塑性流动和硬化的影响。给出了由铁素体基体（α-Fe）和弹性陶瓷颗粒（TiB2）制成的Fe–TiB2 MMC的数值结果。使用代表MMC的合成周期晶胞，单晶和多晶基质进行全场模拟，对于不同的粒子间距。与传统的晶体可塑性相比，观察到的等效应力，累积塑性应变和GND密度场与颗粒间距的强烈相关性。对于不同的MMC微观结构，研究了这些力学场与微观结构特征之间的相关性，以及它们对局部和整体力学行为的影响。