Simulation In Density Variation Of Grass Piece Based On Herbage Compression Experiment

The density of bale is a significant qualification of baler. This research chooses fresh alfalfa as the experimental material which compressed in 9KG-350 high density baler. It takes the grass piece formed in one feeding as research unit, simulating and analyzing the density variation of grass piece during the entire compression process based on the compression experiment.The three-dimensional digital model of compression equipment and chamber are obtained based on UG package .A ADAMS-based geometric model of grass piece is built , taking the rheologic characteristic of alfalfa into consideration . The equivalent stiffness coefficient and damping coefficient of grass piece model are acquired through dealing with experimental force and deformation data ,according to the mathematical model of spring and damper in ADAMS .After that, it performs simulation, gaining the density curve about density variation of grass piece model in the entire compression process . By analyzing the curve ,it attains the suitable positions for packing the bale and puts forward some suggestions for raising the density of bale. The final section of this paper makes a simulation animation, which shows deformation of grass piece along chamber and the motion of compression equipment. The outputs of the research offers important references to study the mechanism of density forming during compression process. Moreover, some results can be help in directing the design of baler and the production of bale.