Moddelling Fatigue Crack Closure Using Dislocation Dipoles

Over the past 30 years the study of fatigue crack closure has been one of the most challenging research topics in fatigue crack growth. This phenomenon was first noticed by Elber [1] and then has been documented by several researchers, both experimentalists and analysts. Different closure mechanisms have been observed, although the primary mechanism of closure seems to be plasticity-induced. One of the reasons why fatigue crack closure has been so extensively studied is because of the need of predicting fatigue lives of structural components, e.g. aircraft industry. It has been proved that fatigue crack closure plays an important role in crack growth rates together with load ratio and load history.