多轴非比例加载下疲劳短裂纹扩展速率的探讨

RESEARCH ON SHORT FATIGUE CRACK GROWTH RATE UNDER NON-PROPORTIONAL MULTIAXIAL LOADING

为了揭示出多轴非比例加载下疲劳短裂纹扩展的规律,利用搜寻临界面的方法确定短裂纹的萌生与扩展的方向,在临界面上分析多轴非比例加载与单轴加载下疲劳短裂纹扩展律的相似性,应用载荷的等效原理,类比单轴加载的研究过程,并将力学参数加以修改,导出多轴非比例加载下疲劳短裂纹扩展速率的计算公式。

As the laws of short fatigue cracks growth under non-proportional muhiaxial loading are supposed to be revealed, what is expected to be achieved is mainly about the direction of initiation and propagation for short fatigue crack is determined by the method of searching for critical plane. The similarity of short fatigue crack growth rate by non-proportional muhiaxial loading and muhiaxial loading respectively is analyzed on the critical plane. Moreover, the equivalence of loading is applied. The process of muhiaxial loading is analogized. The mechanical parameter is modified. Therefore, the formula of short fatigue crack growth rate by non-proportional multi-axial loading could be carried out.