中文摘要：

论文提出了一种由光滑件疲劳寿命试验数据预测缺口件疲劳寿命分布的有效应力法．该方法中缺口件的裂纹可能萌生表面被分解成一个个微元，整个表面可看成是这些微元组成的一个串联模型，按照串联概率失效模型，缺口件的疲劳强度失效概率就可以由各微元的疲劳强度失效概率计算得到，其中微元的疲劳强度失效概率是由光滑件的疲劳强度失效概率通过最弱环节理论计算得到的．在缺口件的疲劳强度失效概率表达式中，引入了有效应力的概念，用它查取光滑件的疲劳寿命试验数据就可以直接得到缺口件的疲劳寿命分布．该方法可以同时考虑到应力梯度和试件尺寸对缺口件疲劳寿命分布的影响．进行了材料LY12CZ的带中心孔缺口件的寿命算例分析，预测结果和试验结果吻合良好，表明该方法是有效的．

英文摘要：

The effective stress model for predicting the fatigue life distribution of notched specimens from fatigue life test data of smooth specimens is developed in this paper. In this model, the possible crack initiation surface of the notched specimen is separated into many micro-elements and the surface is consid- ered as a series model of these micro-elements. Thus, according to the series failure model, the fatigue strength failure probability of the notched specimen can be calculated from that of the elements, which can be determined from the fatigue strength failure probability of the smooth specimen by using the weakest- link theory. In the formula of the notched specimen fatigue strength failure probability,the parameter of ef- fective stress is introduced. Employing this parameter to refer to the fatigue life test data of smooth speci- mens would lead to the fatigue life distribution of notched specimens. This model reflects the influence of both stress gradient and component size on the notched specimen fatigue life distribution. An example of centre hole notched LY12CZ specimens was accomplished. The predicted result is in good agreement with the test result ,which shows that this method is effective and practical.