Seminar announcement, July 25 2019, FATIGUE CRACK GROWTH MODIFICATION FOLLOWING THE OCCURRENCE OF AN OVERLOAD, by Enrico Salvati University of Oxford, Department of Engineering Science

A single anomalous load instance within an otherwise constant amplitude fatigue loading framework can be thought of as the simplest case of variable amplitude loading. It is therefore of fundamental importance to understand the mechanisms responsible for fatigue crack growth change in this simple case, before attempting to develop approaches for reliable prediction of crack propagation under variable amplitude conditions. In this study modern techniques, such as synchrotron XRD and SEM imaging, DIC analysis and FE modelling are used with the purpose of elucidating the main physical mechanisms contributing to crack growth rate alteration, namely the plasticity-induced crack closure and the presence of compressive residual stress ahead of the crack tip. An approach allowing the influence of different mechanisms to be separated is presented. The implications of this results and potential future developments are discussed.