中文摘要：

该研究应用一个材料失效分析模拟软件MFPA^2D，以硼玻璃作为典型的脆性材料，通过对单向拉伸下含不同倾斜角度裂纹玻璃失效情况的数值模拟，重点研究含不同裂纹角的倾斜直通裂纹玻璃试样存单向拉伸下的复合应力效应。研究表明，在这种情况下裂纹尖端存在的三种类型应力：KⅠ，KⅡ及平行应力对裂纹扩展有不同的作用。对于脆性材料的平面应力问题，KⅠ是裂纹扩展的主要因素，KⅡ起辅助作用，平行应力对裂纹扩展有抑制作用。这与传统概念所认为的对于玻璃和陶瓷类脆性材料，断裂完会由Ⅰ型应力强度决定有所不同，对于认识脆性材料的失效机理和断裂预防具有积极意义。

英文摘要：

The effects of mixed stress on glass specimen with an inclined straight-through crack were investigated by means of FEM and failure simulation. The simulation results of crack initiation and fractures for various inclined cracks and the figures of calculated KⅠC, KⅡC corresponding to different crack angles in glass samples were obtained. It demonstrated that three types of stresses existed in the crack＇s tip： mode Ⅰ stress intensity factor, mode Ⅱ stress intensity factor, and the stress parallel to the crack. It was disclosed that, for brittle materials in plane stress state, mode Ⅱ stress intensity and parallel stress have a considerable influence on the crack growth. Mode Ⅰ stress intensity is the dominating factor, and mode Ⅱ stress intensity is subordinate but the tensile stress parallel to the crack plays a role in the crack arrest. This result is different from the traditional concept that the fracture of the brittle materials like glasses and ceramics is determined by mode Ⅰ stress intensity alone.