FATIGUE INITIATION OF CRACK UNDER MODE III AND MIXED MODEI + III LOADS IN A 9CR STEEL

摘要

To contribute to the improvement of knowledge of the behavior of 9Cr-1Mo steel, particularly on the topic offatigue life prediction, cyclic tests of fracture mechanics have been practiced on two types of notched specimens atthe CEA, submited to simple or combined loadings, in order to determine experimentaly the number of cycles toobtain the initiation of a crack. These results are confronted with the evaluations obtained by using a simplifiedrule of the French design code, RCC-MR, the σ d method for the prediction of the initiation of a crack at the tip ofa geometrical singularity.