中文摘要：

提出了一种考虑尺寸效应的缺口件疲劳寿命预测方法。该方法首先将缺口件等效成一个参考光滑件，参考光滑件与缺口件外加应力的比值由缺口件疲劳缺口系数决定，参考光滑件尺寸按裂纹可能萌生区域面积相等的原则确定。再基于最弱环节理论，将参考光滑件等效成一个与已具有试验数据的光滑件（称为标准光滑件）尺寸相同的新光滑件，它们外加应力的比例由Weibult指数和尺寸比例确定。在两次等效的基础上，最终建立缺口件与标准光滑件之间的联系，并提出等效应力的概念，用它查取标准光滑件的疲劳寿命试验数据可直接得到缺口件的疲劳寿命。该方法可考虑到缺口件疲劳损伤场大小对疲劳寿命的影响，并可消除用相同疲劳损伤量查取不同尺寸光滑件的试验数据寿命预测结果不同的现象。进行了材料I。Y12CZ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：

A method for predicting the fatigue life of notched specimen considering the size effect is pro posed. In this method, firstly the notched specimen is made equivalent to a reference smooth specimen. The ratio of the stresses on them is dependent on the fatigue notch factor. The size of the reference smooth specimen is determined according to the principle of having the same area of possible crack initia tion surface as the notched specimen. Then based on the weakest link theory, the reference smooth specimen is made equivalent to a smooth specimen which has the same size as the smooth specimen whose experimental data is already available （here after to be called the standard smooth specimen）. The ratio of stresses on them is dependent on Weibull exponent and the ratio of their sizes. Based on the above equivalences, the relation between the notched specimen and the standard smooth specimen is es tablished, and the parameter of equivalent stress is introduced. Employing this parameter to refer to the test data of standard smooth specimen would lead to the fatigue life of notched specimen. This model re flects the influence of fatigue damage field area on the fatigue life of notched specimen, and can eliminate the phenomenon that referring to the test data of smooth specimens of different sizes using the same value of fatigue damage parameter would result in different values of fatigue life. An example of centre hole notched LY12CZ specimens is accomplished. The predicted result is in good agreement with the test result, which shows that the method is effective and practical.