Introduction to Solid Mechanics & Materials Engineering.
Research in Solid Mechanics has a long tradition in Oxford, initiated by Hooke, whose work on the elasticity of springs may be regarded as the foundation of the mechanics of deformable solids. At present activities encompass many techniques (experimental, theoretical and numerical) and spread over a wide range of materials (composites, metals, polymers, biomaterials, etc.).
This research line focuses on the development and use of computational modelling techniques for many types of materials and structures, ranging from crystalline metals or composite materials to nanoscale structures and biomaterials. The activities of Dr Antoine Jérusalem and Prof Nik Petrinic involve the development and use of advanced numerical techniques such as massive parallel computation, XFEM, meshless methods, GPU solvers, DG methods, etc.
Research in the Solid Mechanics and Materials Engineering Group covers a wide range of areas in Structural Integrity, particularly in the fields of fatigue and fracture. Professors David Hills, Alexander Korsunsky, and David Nowell are 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 in the area of contact mechanics and fretting fatigue, and there is an extensive range of testing machines which 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. Fatigue crack initiation processes are also studied, using crystal plasticity and continuum approaches.
Study of strain rate dependent behaviour of materials has a long history at the University of Oxford, initiated by the first holder of the Chair of Engineering Science, Professor Jenkin and followed by Campbell, Harding and Ruiz who set the conditions for the present Impact Engineering Team to develop as an integral part of the Solid Mechanics and Materials Engineering Group. Current research efforts led by Prof. Nik Petrinic and Dr Clive Siviour are directed towards an integrated experimental-numerical approach to predictive modelling of strain-rate and temperature dependent response of solids to loading at different length scales. The addressed systems range from natural materials, including live-tissue, to advanced, man-made engineering materials and systems such as high-performance metallic super-alloys, composites, ceramics and hybrid cellular materials.
Our work in Materials Engineering is highly interdisciplinary and centres on the development of novel structural and functional materials for a wide range of technological applications. Ongoing research interests encompass advanced materials such as ferroelectrics, polymers, metal-organic frameworks, energy storage materials, nanocomposites, superalloys, and coatings. We establish complex structure-property relationships using state-of-the-art materials characterisation techniques, ranging from atomic force microscopy, electron microscopy and nanoindentation, all the way to synchrotron diffraction, microtomography, and neutron scattering at large-scale facilities.
Understanding the behavior of complex, hierarchically structured materials requires the combination of different modeling techniques. We use implicit and explicit finite element simulations of continua and microstructured alloys, ceramics and polymers, along with discrete dislocation dynamics and molecular dynamics simulations, to consider such phenomena as adiabatic shear bands, crystal slip and dislocation pile-up and interaction, twinning and phase transformations, in materials ranging from aerospace alloys to structural and functional ceramics to biological materials such as human dental tissues.