Plasticity Model and Numerical Simulation of Extruded Oilseeds in Closed Cell

Abstract

By using of Kuhn`s yield criterion, plasticity constitutive equations of extruded oilseeds in a closed cylinderical cell were developed. The model parameters were identified from experimental stress—strain using an inverse method. The maximum relative deviations between the measured and the simulated value of soybean and cottonseed are 8.5% and 5.1% respectively, and the average relative deviations are 4.9% and 3.8% respectively. The results of numerical simulation for confined pressing of granular soybeans and cottonseeds in the closed cylinderical cell indicated the following facts that granular soybeans and cottonseeds conform to the model of three power curve, the plasticity constitutive equations can describe the plastic deformation for extruded soybean and cottonseed, and Kuhn`s yield criterion can be used as theoretical basis for plasticity model of granular soybeans and cottonseeds.