STATISTICAL ANALYSIS OF FATIGUE PROPERTIES OF HIGH STRENGTH STEELS BASED ON MATERIAL STRENGTH DATABASE FOR RELIABILITY DESIGN OF MACHINES AND STRUCTURES

摘要

Main conclusions obtained in this study are summarized as follows; (l) P-S-N characteristics of typical structural steels are quantitatively analyzed by using the database of MSDRD, and the numerical results obtained here can be used as the reliability design data for the mechanical structures. (2) Fatigue life distribution of high strength steels tends to split into short and long life regions at low stress levels around the fatigue limit. Thus the distribution pattern at such stress levels should be represented by mixed mode Weibull distribution. (3) According to the present analyses, the above splitting phenomenon takes place, if the tempering temperature is lower than 873K(600°C) and, therefore, the tensile strength exceeds the critical level of 1300MPa.