The Effect of Stress Ratio During Crack Propagation and Fatigue for 2024-T3 and 7075-T6 Aluminum

An effective stress, σ¯ = σmax1-mΔσm where m is assumed to be a material constant, is shown to predict the effect of stress ratio on crack propagation and fatigue life for two aluminum alloys. Simple approximations of notch stress and strain using Neuber's notch rule are introduced to extend the predictions of stress-ratio effects to inelastic notch behavior.