In this research, we are modeling the behavior of spherical and non-spherical particle aggregates by a combination of numerical methods including finite element and discrete-element approximations. Our primary objective is to study the mechanical behavior of these particle aggregates via their constitutive law and yield surface characteristics.
Our current models include three-dimensional studies of spherical particle aggregates using a network model and a two-dimensional model of viscoplastic spherical particle aggregate compaction using an iterative finite element procedure. A typical particle packing is shown on the left along with the basic behavior of the yield surface for isostatic precompaction, where our network model is compared with results from a statistical random particle aggregate. Results from our two-dimensional aggregate are shown in the sequence of figures at the bottom of the page, with the viscoplastic particles gradually eliminating the void space through the enforcing of incompressibility.
This work is currently being funded by the National Science Foundation and the Alexander von Humboldt Research Foundation. Members of the research team include Mr. Yu-Ching Wu (CSU), Professor Erik Thompson (CSU), Professor Robert McMeeking (UCSB), Dr. Karsten Thompson (LSU), and Professor Paul Heyliger (CSU).