A fracture mechanics analysis of fatigue crack growth data for various materials

✍ Scribed by N.E. Frost; L.P. Pook; K. Denton

• Publisher: Elsevier Science
• Year: 1971
• Tongue: English
• Weight: 883 KB
• Volume: 3
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(71)90003-8

✦ Synopsis

A large amount of previously published fatigue crack growth data obtained from 10in. wide centre-cracked sheet specimens of various materials has been re-analysed in terms of the range of stress intensity factor (AK) and the results presented as master curves of crack growth rate against AK. In addition, data obtained previously from fatigue tests on edge-cracked plate specimens concerning the minimum cyclic stress that would just not cause a crack of a given length to grow have been similarly analysed.

Various general features of fatigue crack growth are discussed in the light of this re-analysis, and it is shown that no single crack growth relationship can represent adequately fatigue crack growth data. NOTATION A,B, C materialconstants a crack length Kt stress intensity factor (opening mode) Kc fracture toughness (critical value of Kt) rn an exponent N number of cycles O-m --(3" a R st re s s ratio (--~-~-~) rp plastic zone radius W specimen width AK range of Klin fatigue cycle AKc critical value of AK tr gross stress o-a alternating stress t~m mean stress O'ma x maximum gross stress during fatigue cycle, tr,,, + cr,, gx maximum net section stress ~y yield stress (taken as the 0.1 per cent proof stress)