Granular & Geomechanic
Granular materials, including natural sands or industrial powders for additive manufacturing or pharmaceutical tablets, and geo-materials, such as rocks, soils and concrete, are complex materials involving multiscale structures and mechanisms that exist in environments/applications where coupled phenomena, such as hydro-mechanical coupling, are important. Our research in this area is primarily experimentally-based and involves developing detailed experiments to investigate the inter- and intra-particle scale origins of the bulk material behaviour as well as the coupling between structure, mechanics and transport properties such as fluid flow and elastic wave propagation.
In our work we make extensive use of x-ray and neutron techniques in conjunction with “in-situ” testing to probe the nano-, micro-, meso- and macro-scale simultaneously to understand, for example, the processes of force transfer and failure mechanisms and the couplings across scales. Key aspects of the work include the quest for one of the holy grails of granular mechanics: the combined measurement of the kinematics and force transmission in real 3D materials during loading, which we investigate with combine x-ray or neutron scattering coupled to optical, x-ray or neutron imaging and digital image/volume correlation. Another key direction is to understand the variation and evolution of hydraulic properties of rocks due to preexisting or deformation-induced heterogeneity. Current work also involves the study of granular dynamics facilitated by ultrafast x-ray imaging.
The research has implications in terrestrial geomechanical/geotechnical engineering challenges, e.g., in optimising foundations or tunnels to mitigate risks of structural failure, and even extra-terrestrial challenges relating to mechanical behaviour of soils at lunar/martian landing sites. In a more general sense, the research will have impact on more diverse areas involving granular mechanics including industrial powder processing, pharmaceutical tablet manufacturing and food science, amongst others.