Fatigue Crack Growth Thresholds under Negative Stress Ratio for Aluminium Alloys

Abstract:

When fatigue crack growth rate da/dN = 0, the stress intensity factor range ΔK_I is a threshold and it is expressed by ΔK_I = ΔK_th. The threshold ΔK_th is important for design, repair/replacement, particularly, trouble shooting for cracked components. However, the thresholds were not well codified. Authorized and consensus ΔK_th are required. This paper introduces the current thresholds provided by fitness-for-service codes and the definition of ΔK_th under negative stress ratio R is discussed. Finally, the threshold ΔK_th for aluminum alloys in air environment is proposed for fitness-for-service codes.

• Periodical: Key Engineering Materials (Volume 810)
• Pages: 34-39
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.810.34
• Online since: July 2019
• Authors: Kunio Hasegawa*, Saburo Usami, Bohumír Strnadel
• Keywords: Aluminium Alloy, Fatigue Crack Growth Threshold, Fitness for Service, Negative Stress Ratio, Stress Intensity Factor Range

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