Effect of character, value, and sequence of overloads on the fatigue crack growth in 2024-T3 aluminum alloy

The results of testing for overloads and underloads of aluminum alloy specimens at near-threshold crack growth rates aimed at identifying the most suitable model for the fatigue life estimation are analyzed. The paper describes the analysis of the influence of the character and value of overloads and underloads on the fatigue crack growth. The obtained curves for crack growth and fatigue life could not be explained by classical crack growth models. This necessitates the development of a new model.