PHYSICAL MATHEMATICS SEMINAR


TITLE:		GRANULAR PACKING AND HOPPER FLOW
 


AUTHOR:		JAMES W. LANDRY
		Sandia National Laboratories
		New Mexico


ABSTRACT:   

We explore the formation and structure of granular packings using large-scale
molecular dynamics simulations.  The three-dimensional packings are created 
through pouring or sedimentation and then settle under the influence of gravity. 
The final packing state depends strongly on the history of construction, especially
in the case of frictionless versus frictional packings.  I compare the stress profiles
in our packings to the classical theory of Janssen and show how the deviation of 
the stress from the Janssen form is related to the Coulomb failure criterion.  

Hopper flow has recently been suggested by many groups as an ideal system for 
studying the onset of jamming, both experimentally and through simulations.  I present 
fully three-dimensional simulations of hopper flow and explore how the internal structure
and force distributions change with decreasing flow velocity.  While there is a great 
Difference between the force distribution of the jammed state and that of the flowing state,
different flow velocities have a very small effect on the force distribution.



TUESDAY, APRIL 29, 2003  
2:30 pm
Building 2, Room 338

Refreshments will be served at 3:30 PM in Room 2-349

                        

Massachusetts Institute of Technology
Department of Mathematics
Cambridge, MA  02139