一种描述缺口根部初始裂纹长度的客观量

An Objective Amount for Describing lnitial Crack Length at the Notch Root

工程构件的初始裂纹长度是人为规定的，不具有客观性。而依据疲劳损伤累积理论所确定的裂纹形成寿命，其对应的裂纹长度是一个相对客观的参量。本文依据裂纹扩展的累积损伤模型和材料的ε－Ｎ曲线，提出了一种确定缺口试件初始裂纹长度的方法。文中计算了一些材料的初始裂纹长度，并与试验结果和其它文献的结果进行了比较，结果相当吻合，由本文的方法所确定的初始裂纹长度是一个客观参量，它为疲劳寿命分析提供了一个客观的基础，具有实际应用价值。

The initial crack length of engineering components usually be defined subjectively but not objectively.The crack length which is related to the theories of fatigue life prediction should be objective. A method of calculating the initial crack length based on cumulative model of crack growth and ε-N curve is set up in the present paper.Some initial crack lengths are calculated and compared with an experimental result and the result of another reference, and good agreement is obtained.The initial crack length obtained by the method of this paper is relatively objective,so the fatigue life can be predicted based on a relatively objective foundation.Hence, the method provided here has practical value.