This paper presents a study on dislocation theory based short/small crack modelling, and its application for short crack growth life analysis on 2024-T351 aluminum specimens. The dislocation theory was applied to determine the crack tip opening displacement of a microstructurally short crack by taking into account the effects of microstructural features, such as grain size, orientation, and grain boundary. The crack tip opening displacement was then used as the parameter for calculating the short crack growth rate. In this work, an existing crack tip opening displacement model was modified for estimating the short crack life of 2024-T351 single edge notch tension specimens, which were tested in an Advisory Group for Aerospace Research and Development program. The analytical results matched the test results reasonably well.

Dislocation Theory Based Short Crack Model and Its Application for Aircraft Aluminum Alloys. M.Liao: Engineering Fracture Mechanics, 2010, 77[1], 22-36