The aim is to develop a new understanding of the micromechanics of railway trackbed subjected to dynamic loads induced by high speed trains. This should lead to safer design of high-speed railway systems which require less maintenance and, therefore, are more sustainable.

For granular materials with low thermal conductivity heat transfer occurs through interstitial gases as well as through physical contacts.  Existing particle based models are ill suited to dense systems so a multi-scale approach has been used to correlate the local packing structure to the gas contribution to conductive heat transfer in dense granular systems.

The principal aim is to characterise the flow properties of dense granular systems. In particular, the influence of different particle-shape representation techniques in the Discrete Element Method (DEM) is assessed. Additionally, experiments in a silo centrifuge device to determine the bulk response of granular assemblies under realistic stress states are being carried out. This work is part of T-MAPPP (Training in Multiscale Analysis of multi-Phase Particulate Processes), an FP7 Marie Curie Initial Training Network (https://www.t-mappp.eu).

Suspensions, mixtures of a fluid and particles, are widespread in nature and industry. However, many open questions, such as the particle interactions in dense suspensions, have not been answered [1].