An investigation on single overload fatigue crack growth retardation, Part-2 (Crack closure decomposition)

Numerical investigation was carried out to demonstrate the validity of a new concept for evaluating the crack closure values due to plasticity effect, following single overloads (SOL). The crack closure (or opening) stress was decomposed into two components, one that results under constant amplitude loads (CAL), and the other that is due to application of single overload. The model based on plasticity induced crack closure was developed and a computer code was framed for prediction of fatigue growth and crack closure stress. The fidelity of the program was tested by comparison of the results with the experimental data obtained from recent literature. Results from numerical method agreed well with the data. The numerical scheme presented is robust and can be used with confidence for design and analysis.