Crack closure and influence of cycle ratio R on fatigue crack growth in type 304 stainless steel at room temperature

✍ Scribed by H.U Staal; J.D Elen

• Publisher: Elsevier Science
• Year: 1979
• Tongue: English
• Weight: 775 KB
• Volume: 11
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(79)90004-3

✦ Synopsis

Crack growth rate and crack closure during fatigue of type 304 stainless steel are measured with an optical microscope and television camera. Based on the crack closure data an effective stress intensity range AKFR is calculated. The da/da vs A&-curves indicate that crack closure could account for the R-influence as normally derived from do/dn vs AK-curves. Measurements of striation spacing lead to the conclusion that at higher da/dn values crack growth mechanisms dependent on K,., play an important role; these mechanisms are probably responsible for the R-influence in the range of the higher daldnvalues.