Professors David Hills and Alexander Korsunskyare interested in the performance of materials and structures under complex monotonic and cyclic loading conditions, including multiaxial stress states and high stress gradients. A particular focus of our work has been contact mechanics and fretting fatigue, and an extensive range of testing machines can be used to provide model validation. Other work focuses on residual stress at the micro- and macro-scale and on how this affects fatigue performance. More fundamental work is carried out to investigate crack tip deformation processes using digital image correlation and X-ray tomography to validate analytical and numerical modelling. This will feed into improved methods of fatigue life prediction, particularly under non-uniform loading.