Effects of shape on unstable growth of cavities interacting with surrounding small voids
Effects of shape on unstable growth of cavities interacting with surrounding small voids
复制标题
形状对与周围小空隙相互作用的空腔不稳定生长的影响
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
V. Tvergaard
中科院分区：
文献类型：
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作者：
V. Tvergaard
最近，人们研究了在含有许多空穴的韧性金属中空穴不稳定增长的可能性。中心的球形空腔离散表示，而周围的小规模的空隙表示的多孔韧性材料模型的字段量，指定在周围的金属中的空隙体积分数的变化。在这里，通过考虑不同的初始球形空隙形状的中心空隙的初始形状的影响进行了分析。中心空洞周围空洞体积分数场的演化对空洞形状非常敏感。如果周围材料中没有孔隙，则在高三轴应力场中的中心空隙在不稳定生长发生之前朝向近球形发展。然而，在周围的小规模的空隙的存在下，孔隙度场的演变有很大的影响的最大应力点的发生，在那里的中心空隙将开始快速增长与周围材料中的断裂演化的相互作用。
The possibility of unstable cavity growth in a ductile metal containing many voids has been studied recently. The central spherical cavity was discretely represented, whereas the surrounding small-scale voids were represented by a porous ductile material model in terms of a field quantity that specifies the variation of the void volume fraction in the surrounding metal. Here the influence of the initial shape of the central void is analysed by considering various initial spheroidal void shapes. The evolution of the void volume fraction fields around the central void is very sensitive to the void shape. If there is no porosity in the surrounding material, the central void in a high triaxiality stress field develops towards a near spherical shape before unstable growth occurs. However, in the presence of surrounding small-scale voids the evolution of the porosity fields has much influence on the occurrence of the maximum stress point, where the central void will start to grow rapidly in interaction with fracture evolution in the surrounding material.