Fatigue life and crack growth prediction methodology
The capabilities of a plasticity-induced crack-closure model and life-prediction code to predict fatigue crack growth and fatigue lives of metallic materials are reviewed. Crack-tip constraint factors, to account for three-dimensional effects, were selected to correlate large-crack growth rate data as a function of the effective-stress-intensity factor range (delta(K[sub eff])) under constant-amplitude loading. Some modifications to the delta(K[sub eff])-rate relations were needed in the near threshold regime to fit small-crack growth rate behavior and endurance limits. The model was then used to calculate small- and large-crack growth rates, and in some cases total fatigue lives, for several aluminum and titanium alloys under constant-amplitude, variable-amplitude, and spectrum loading. Fatigue lives were calculated using the crack growth relations and microstructural features like those that initiated cracks. Results from the tests and analyses agreed well.
- Research Organization:
- National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center
- OSTI ID:
- 5160333
- Report Number(s):
- N-94-23279; NASA-TM--109044; NAS--1.15:109044; CONF-9309364--; CNN: RTOP 538-02-10-01
- Country of Publication:
- United States
- Language:
- English
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