Principal Investigator Kenneth Kamrin
The work of many French physicists dealing with granular rheology hit a high point in the summer of 2006 with the results of P. Jop et al. which showed that a Bingham fluid flow model was in fact able to describe a 3D granular flow. On another front, earlier research detailed a functioning granular elasticity model in the winter of that year which determines stresses in a static granular assembly. Work combines both of these models into one universal granular constitutive law, capable of predicting both flowing regions and stagnant zones simultaneously in any arbitrary flow geometry. The model is implemented as a user material subroutine in the Finite Element Method software package ABAQUS/Explicit. The combined effect of elastic stresses and plastic yielding resolves features such as shear bands which many previously believed to be outside the realm of a continuum model. This work adheres to finite deformation elasto-plasticity theory, a framework which has developed through the ages to become a highly rigorous and complex mathematical science.