In situ analysis of crack fields

Cracks cause the failure of structures that range from nuclear reactors to semi-conductor devices. Cracks are three-dimensional and multi-scale, and propagate in conditions are at the limits of materials performance. Structural engineers need to predict whether and how quickly a crack may propagate, with confidence and without excessive conservatism. Materials engineers aim to understand how the microstructure can be changed to design materials with improved fracture behaviour. As Materials scientists, we seek to investigate the local conditions that exist at the crack tip that allow it to propagate.

Our approach to this fundamental problem is to simultaneously map the strain and stress fields that surround the crack tip as it propagates. This can be done at multiple length scales using advanced materials characterisation methods.  Some recent examples include nuclear graphite (http://dx.doi.org/10.1016/j.carbon.2020.09.072), fatigue cracks in metals (http://dx.doi.org/10.1016/j.ijfatigue.2023.107541, http://dx.doi.org/10.1016/j.prostr.2022.03.139) and cleavage cracks in ceramics (http://dx.doi.org/10.1016/j.jmps.2022.105173).

Several projects are available in this area, with the objective of developing novel methods to understand the interaction between damage processes at the crack tip and the surrounding deformation fields. The failure mechanisms include  brittle fracture, stress corrosion, fatigue and creep in metals, ceramics, polymers and their composites. The research approach couples experimental techniques that include X-ray tomography, X-ray diffraction, electron and optical microscopy and Raman spectroscopy with numerical methods that include inverse modelling and finite element methods.

The projects are suitable for graduates with an engineering, mathematical or physical sciences background.