Mode I fatigue crack growth at notches considering crack closure

摘要

An analytical elastic-plastic model is presented describing the fatigue life of arbitrary engineering components with elliptical notches under constant amplitude loading. A ΔJ_(eff)-based crack growth law is integrated from a starting crack size of micro-structural dimension up to the total fracture of the component. Plasticity-induced crack opening and closure effects are explicitly taken into account. Calculated opening load levels for cracks growing in notch affected areas have been found to be in good agreement with corresponding experimental values determined from notched specimens made of two different metallic materials. Comparison of experimentally determined and calculated crack growth curves for specimens with central notches confirm the satisfactory accuracy of model. The experimental verification of the model's calculation accuracy covers various ductile materials, notch geometries, load amplitudes and mean load effects.