Multiscale mechanics of particulate media
Ken Kamrin, MIT
(Mechanics of Solids and Structures)
Materials of a disordered particulate composition, such as granular matter and colloids, are ubiquitous in industry and as geomaterials in nature. These materials display a number of distinctive phenomena, which differentiate them from ordered materials. Macroscopically, they are capable of behaving both solid-like (elasticity, visco-plastic behavior, shear-banding) and fluid-like (rate-sensitive rheological behavior) depending on loading and the internal material state. This variety stems from a rich microstructural involvement, whose underlying mechanisms and connections to the continuum scale remain unresolved issues of current research. While full discrete simulation offers one approach to modeling these materials, it is generally computationally intractable for large bodies and long times. On the other hand, scale-free continuum approaches can be imprecise due to the crucial role of micro-level fluctuations and finite size-effects. These observations highlight the need for developing multiscale approaches, aimed at bridging the discrete microscale response to the macroscale. This session shall focus on the mechanics of particulate materials at length-scales ranging from the discrete particle-size to the continuum scale -- using theory, simulation, and experimental characterization -- aimed at building accurate multiscaling techniques as well as gaining a deeper general understanding of these materials for the purposes of improved modeling.