Cyclic analysis of a propagating crack and its correlation with fatigue crack growth

Abstract Stress and strain field of a propagating fatigue crack and the resulting crack opening and closing behavior were analysed. It was found that a propagating fatigue crack was closed at tensile external loads due to the cyclically induced residual stresses. Strain range value Δϵ y in the vicinity of the crack tip was found to be closely related with the effective stress intensity factor range ΔK eff which was determined on the basts of the analytical crack opening and closing behavior at its tip. Application of this analysis to the non-propagating fatigue crack problem and the fatigue crack propagation problems under variable stress amplitude conditions revealed that both Δϵ y and ΔK eff were essential parameters governing fatigue crack growth rate.