Fatigue notch sensitivity and the notch size effect

✍ Scribed by A.J. McEvily; M. Endo; K. Yamashita; S. Ishihara; H. Matsunaga

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 769 KB
• Volume: 30
• Category: Article
• ISSN: 0142-1123
• DOI: 10.1016/j.ijfatigue.2008.07.001

✦ Synopsis

It has long been known that the fatigue notch factor K F , given by r w0 /r w , where r w0 is smooth specimen fatigue strength (R = À1) and r w is the fatigue strength of a notch-containing specimen, is less than the theoretical stress concentration factor, K T . Empirical rules have been proposed by Peterson and by Kuhn and Hardrath for the estimation of K F which involve the notch radius and a material constant. El Haddad, Topper and Smith provided one means for understanding the factors determining K F . The present paper provides an alternative approach based upon a consideration of the development of fatigue crack closure. The effect of crack closure on the formation of non-propagating cracks is also discussed.