Abstract:

ESDU 17003 gives graphs showing the rate of increase in crack length per loading cycle plotted against stress intensity factor range for a large group of steels. The curves were obtained by correlating results taken from the literature for tests on steels of tensile strength from 850 to 1970 MN/sq m (123000 to 286000 lbf/sq in). Specimens were tested under constant amplitude loading at room temperature in laboratory air. Included are details of the test specimens, their loading (mainly tensile axial), and the exact composition of the steels. The influence of fracture toughness, mean stress, and material proof stress can be seen in the data and is discussed. Summary curves are included that show the effect of stress ratio and material proof stress on crack growth rates. Two practical worked examples show how the data may be used to establish the life of a component or whether an existing crack will grow.