Stress-Intensity Factors and fatigue growth of surface cracks in notched shells and round bars: two decades of research work

In the present paper, some research results determined by the authors during the last two decades are reviewed. The influence of notches (geometrical discontinuities) on the fatigue life of metallic structural components is analysed. In particular, notches with different shapes (therefore characterised by different values of the stress concentration factor) are examined in the case of both double-curvature shells and round bars under mode I loading. An elliptical-arc surface crack is assumed to exist at the notch root. The stress intensity factor (SIF) is numerically evaluated, and the crack propagation under cyclic loading is analysed through a numerical procedure, which takes into account the aforementioned SIF.