Condensed Matter Seminar: "Jamming of non-circular and deformable particles"

Wed, 09/27/2017 - 16:00 - 17:00
Mark Shattuck (City University of New York)

We study mechanically stable packings of deformable and rigid 2D circulo-polygons using computer simulations. A 2D circulo-polygon is a particle shape formed by the collection of all points equidistant from the edge of a polygon. It is a generalization of the 2D circulo-cylinder and a circle, which are the collections of all points equidistance from a line and a point, respectively. In our model, the circulo-polygon can be deformable, where the only constraint on the particle is that shape factor, the ratio of the area of the polygon to the square of the perimeter, is fixed. We present the densities and average contact numbers for collections of jammed mono- and bi-disperse packings of circulo-polygons for a range of shape factors, edge numbers, and system sizes. For rigid particles, we find mechically stable packings with fewer than isostatic contacts.  For deformable polygons, we identify a new phase transition between non-confluent and confluent systems that occurs when the particle shape factor is comparable to the average shape factor for Voronoi polygons of disk packings.

David Rittenhouse Laboratory, A4