PSI - Issue 59

Ivan Pidgurskyi et al. / Procedia Structural Integrity 59 (2024) 314–321 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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contour with a shape aspect ratio a/c = 0.78 ÷ 0.8, the increase in the overload factor from Q OL = 1.67 to 1.8; 2.0 and 2.2 leads to an increase in the fatigue crack growth retardation N D by 2; 6 and 17.5 times, respectively. An increase in the range of the main load cycle SIF leads to a decrease in the number of delay cycles N D . As the stress ratio increases, the number of delay cycles N D increases. The main regularities of the effect of overloading Q OL = 1.67 on the fatigue surface cracks growth retardation N D with the same length on the surface 2c and different shape aspect ratio a/c = 0.2; 0.5 and 0.786 have been determined. It was established that with a decrease in the shape aspect ratio the retardation N D increases by almost 2 times, which is explained by the decrease in the range of SIF of the main load cycle for the deepest point of the crack front. 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