初始缺陷尺寸分布的尺寸效应研究

 疲劳结构可能的开裂区域面积不同引起结构可能萌生裂纹的初始缺陷尺寸分布各异是造成"疲劳尺寸效应" 的一个可能解释。研究了试样测试部分尺寸大小与萌生裂纹的初始缺陷尺寸分布的关系,并建立了分析模型。模型利用已知的小尺寸试样的初始缺陷尺寸分布和大小试样的开裂面积比,推导出了相同条件下未知大尺寸试样的初始缺陷尺寸分布。这为结构完整性研究以及基于小裂纹扩展理论大尺寸试样的耐久性分析和疲劳全寿命预测打下基础,并为进一步研究"疲劳尺寸效应"创造了条件。

Study of Size Effect on Initial Flaw Size Distribution

Size effect on initial flaw size is a reasonable explanation to "size effect on fatigue life".In this paper,the size effect on initial flaw size is studied and an analysis model is also established.With a known initial flaw size distribution for small specimen and an area ratio,the unknown flaw size distribution for large specimen can be gotten by using the analytical model only if these two structures have the same material and machining conditions.It makes great contributions to structural integrity program.It is also helpful to the studies of durability analysis and total fatigue life prediction by using small crack theory.