2009 年 75 巻 760 号 p. 1771-1776
The author suggested that fatigue lives of the sharp notched specimens of high strength steels the tensile strength of which was higher than 1000MPa, could be estimated only by the stress intensity factor and did not depend on the tensile strength. This result indicates that the fatigue life of the sharp notched specimen is controlled by macro fatigue crack growth rate under small scale yielding. It is well known that macro fatigue crack growth rate under small scale yielding depend on Young's modulus. Therefore, the relationship between the fatigue life and the stress intensity factor of the sharp notched specimen is thought to depend on Young's modulus. In this study, K-N curve of metallic glass and non-ferrous alloys were compared with that of high strength steels and E dependent fatigue of sharp notched specimen was experimentally verified. Its importance on fatigue design of machine and structure using high strength light alloys was discussed and future development was suggested.