Crack Growth in Creep Brittle Materials

这项研究的目的是进行一项综合的 实验，计算和分析研究，将提供 基本了解并量化损害的性质， 蠕变脆性裂纹尖端应力重分布 陶瓷、金属间化合物和粉末冶金等材料 合金，包括工艺区效应和瞬态载荷 条件 还建议设立适当的 蠕变裂纹扩展的局部/整体裂纹扩展准则 蠕变脆性材料 独特的谷物颗粒流解决方案 与边界扩散相关的边界滑动和/或 预期粘度可阐明适当的工艺区 尺寸尺度和空隙增长和聚结的驱动力 这些结果将用于构造合适的裂纹尖端 损伤模型与有限元分析相结合， 理解从实验中显而易见的物理学。 这些进步应该对改善 由蠕变脆性材料制成的部件的失效预测。

The purpose of this research is to undertake a combined experimental, computational and analytical study that will provide a fundamental understanding, and quantify the nature of, damage and stress redistribution ahead of the crack tip for creep brittle materials such as ceramics, intermetallics and powder metallurgy alloys, including process zone effects and transient loading conditions. It is also proposed to establish appropriate local/global crack extension criteria for growing creep cracks in creep brittle materials. Unique granular flow solutions for grain boundary sliding associated with boundary diffusion and/or viscosity are expected to shed light on appropriate process zone size scales and driving forces for void growth and coalescence/ These results will be used to construct appropriate crack tip damage models to be used with finite element analysis to better understand the physics which will be evident from the experiments. These advances should have important implications for improving failure predictions of components made of creep brittle materials.