A FURTHER STEP IN THE MODELLING OF THE MECHANICAL BEHAVIOUR OF BAGASSE

A BETTER understanding of the behaviour of prepared cane and bagasse during the crushing process is believed to be a prerequisite for further improvements to the crushing process. Improvements could be made, for example, in power use, sugar extraction or bagasse moisture. The ability to model the mechanical behaviour of bagasse as it is squeezed in a milling unit to extract juice would help identify how to improve the current process to reduce final bagasse moisture. However an adequate mechanical model for bagasse is currently not available. Previous investigations have shown with confidence that juice flow through bagasse obeys Darcy’s permeability law, that the grip of the rough surface of the grooves on the bagasse can be represented by the Mohr-Coulomb failure criterion for soils, and that the internal mechanical behaviour of the bagasse is critical state behaviour similar to that for sand and clay. Current Finite Element Method (FEM) models available in commercial software have adequate permeability models. However, the same commercial software does not contain an adequate mechanical model for bagasse. Progress has been made in the last ten years towards implementing a mechanical model for bagasse in finite element software code. This paper builds on that progress and carries out a further step towards obtaining an adequate material model.