Abstract

This talk focuses on the constitutive modeling of the mechanical behavior of granular media, with emphasis on the interplay between particle fracture and the collective deformation of grain assemblies. The goal is to use concepts of continuum thermodynamics and fracture mechanics to account for different microscopic sources of energy dissipation, as well as for measurable attributes such as grain size and sorting. The talk discusses a continuum law able to track the evolution of the grain size distribution of a granular system during loading. It is shown that the use of grainsize-dependent scaling laws enables the model to capture the macroscopic hardening caused by the reduction of the mean grain size and the increase of particle coordination. The thermodynamic structure of the theory is also used to express the properties of granular solids as a function of fracture mechanisms defined at the grain scale. It is shown that such link enables the model to capture numerous properties, such as the grain-size dependence, rate-dependence and moisture-sensitivity of crushable granular continua.

Bio

Giuseppe Buscarnera is Assistant Professor of Geotechnical Engineering at Northwestern University, which he joined in September 2011. He received his B.Sc. (2004), M.S. (2006) and Ph.D (2010) all in Civil Engineering from the Politecnico di Milano, Italy. During his doctoral and post-doctoral studies he has collaborated with several academic institutions around the world, such as the Universitat Politecnica de Catalunya (Spain), the Massachusetts Institute of Technology, and The University of Sydney (Australia). Dr. Buscarnera's research focuses on the area of geomechanical modeling, and in particular on the theory of material stability, the formulation of constitutive models for soils and rocks, the multi-physics of porous media and the application of geomechanics to landslide hazard zonation and energy geomechanics. Currently, he is serving as the PI of various sponsored research projects on these topics and his research has been awarded with the Faculty Early Career Development Award (CAREER) from the National Science Foundation.

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