Stefanos Papanicolopulos: Granular materials
From Billy Rosendale on October 4th, 2016
Granular materials exhibit complex mechanical behaviours quite different from that of other types of materials, so that we could consider them as a separate state of matter. The grains themselves are solid, the space between the grains is usually occupied by a liquid or a gas (usually water or air).The overall granular material, however, can behave in a solid-, liquid- or gas-like way, often changing between different behaviours with little change in the applied external conditions.
Granular materials play a significant role across engineering and technology, for example in geotechnical engineering or industrial processes. In many applications we are interested in describing the “failure” of the material, that is the transition from solid-like behaviour to flow of the material. While failure clearly happens at the discrete level of the grains, when possible it is much more convenient to employ a continuum mechanics description which disregards individual grains but retains average properties of the material at each point.
My research focuses on the use of continuum mechanics to model the effect of the granular microstructure on the overall solid-like behaviour of granular materials. I am especially interested in how the microstructure, especially the size of the individual grains, affects the failure of granular materials. One aspect of my work concerns constitutive modelling, that is appropriate mathematical descriptions of material behaviour, to incorporate in the continuum description the information about the granular microstructure and how it affects the material behaviour during and after failure. Another equally important aspect is the numerical implementation of the mathematical descriptions into engineering simulation software, especially into finite element codes.
I am currently working on the numerical implementation of plastic constitutive models that can model the localisation of deformation observed during failure accurately and in a physically consistent way. An important aspect of this work is the development of efficient models and numerical implementations that will allow solving large-scale problems in three dimensions.
This research effort is currently funded from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement n° 618096.
Find out more:Dr Stefanos Aldo Papanicolopulos, School of Engineering profile: http://www.eng.ed.ac.uk/about/people/dr-stefanos-aldo-papanicolopulos
Edinburgh Research Explorer: http://www.research.ed.ac.uk/portal/spapanic