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arXiv 1603.08910cond-mat.mtrl-sci
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多相材料中的断裂:为什么某些微结构比其他微结构更关键

Fracture in multi-phase materials: why some microstructures are more critical than others

T. W. J. de Geus, R. H. J. Peerlings, M. G. D. Geers

摘要:

我们的目标是解开机制,导致故障的韧性两相材料-由一个韧性软相和一个相对脆硬相。采用理想化的细观结构模型,系统、透明地研究了损伤扩展问题。分析揭示了不同的微观结构特征周围的早期空隙,从而硬相的区域与拉伸轴和软相的区域与剪切方向对齐。这些特征在表现出损伤扩展的区域中一致地被发现,由此损伤保持初始驱动,即空隙彼此独立地成核。在本地化,损害控制在一个较长的长度尺度依赖于一个关键的相对位置的“启动热点”。在软相的带中,损伤迅速增加,其中几个空隙与剪切方向对齐。空隙的相对排列决定了微结构是早期失效还是在显著更高的应变下失效。虽然需要进行大量的研究来完善这些发现,以获得真实或更现实的微观结构,特别是在三维空间中,但本文为更深入地了解多相材料的最终失效开辟了一条途径。

英文摘要:

Our goal is to unravel the mechanisms that lead to failure of a ductile two-phase material - that consists of a ductile soft phase and a relatively brittle hard phase. An idealized microstructural model is used to study damage propagation systematically and transparently. The analysis uncovers distinct microstructural features around early voids, whereby regions of the hard phase are aligned with the tensile axis and regions of the soft phase are aligned with the shear directions. These features are consistently found in regions exhibiting damage propagation, whereby the damage remains initiation driven, i.e. voids nucleate independently of each other. Upon localization, damage is controlled on a longer length-scale relying on a critical relative position of 'initiation hot-spots'. The damage rapidly increases in bands of the soft phase wherein several voids are aligned with the shear directions. The relative arrangement of the voids determines whether the microstructure fails early, or at a substantially higher strain. Although much research is needed to refine these findings for real or more realistic microstructures, in particular in three-dimensions, this paper opens a route to a deeper understanding of the ultimate failure of multi-phase materials.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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