Resistance to cleavage cracking and subsequent shearing of high-angle grain boundary
Resistance to cleavage cracking and subsequent shearing of high-angle grain boundary
复制标题
抗解理裂纹和随后的大角度晶界剪切
DOI：
10.1016/j.engfracmech.2009.12.009
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发表时间：
2010
影响因子：
5.4
通讯作者：
Y. Qiao
中科院分区：
文献类型：
--
作者：
Weiyi Lu;Jin Chen;S. S. Chakravarthula;Y. Qiao
在先前的实验研究中，观察到解理前沿穿过大角度晶界的突破过程可以是高度不均匀的。虽然边界的中心部分可以很平滑地劈开，但其余部分必须被剪切开。本文对晶界剪切的陷阱效应作了较详细的分析。在剪切完成之前，裂纹翼面被局部地钉扎在一起，并且必须提供桥接应力。桥接应力对穿透晶界的解理前缘的局部应力强度有负贡献，因此必须增加裂纹扩展驱动力。一个封闭的形式方程推导出相关的整体断裂阻力的断裂模式，通过能量分析。
In a previous experimental study, it was observed that the break-through process of a cleavage front across a high-angle grain boundary can be highly nonuniform. While the central part of the boundary can be cleaved quite smoothly, the rest parts must be sheared apart. In this paper, the trapping effect of grain boundary shearing is analyzed in considerable detail. Before the shearing is completed, the crack flanks are locally pinned together and a bridging stress must be provided. The bridging stress has a negative contribution to the local stress intensity at the cleavage front segment that penetrates across the grain boundary, and thus the crack growth driving force must be increased. A closed-form equation is derived to relate the overall fracture resistance to the fracture mode through an energy analysis.