Rheodynamic Characteristics Of Herbage Materials In Compression And Optimization Of Compression Process

Rheodynamic Characteristics of herbage Materials in Compression were tested in order for reasonable utilization of the herbage resources and environmental protection . Firstly,a test set for herbage compression was designed and manufactured,on which both the single-factor experiments and multi-factor experiments can be carried out ,also the cross-area, length of the compression chamber ,the start and stop time of compression stroke can be adjusted .A data acquisition system was developed based on the virtual instrument technology ,by which the signals of axial compressing force ,side force ,and herbage material's (wafer's) depth as well as the herbage of entire compression process were detected .The data log file can be converted into other formats for saving, and can be loaded into MatLAB for conducting the data processing ,calculation and plot. Therefore the efficiency and reliability of the data processing is increased greatly.The single-factor experiments and multi-factor experiments were performed and the following conclusions were obtained :1 The effect of section shape and size of the baling chamber on herbage compression was studied in case of the other factors unchanged .By taking the amount of the material fed by one time as the research object ,the rheodynamic characteristics were studied in the entire process of compression ,showing that the compression of herbage is a great deformation process ,the relationship between stress and strain is nonlinear ,and the load curve differs from the unload one which is zero offset.After the formation of herbage wafers, their compression modulus increased subsequently under the action of the cycle load ,the difference of the unload-curve profiles is increased gradually with the one of direct compression process ,and the recovery modulus of each wafer is increased as well ,resulting in the increase of the resisting deformation .In the all compression process ,the stress relaxation occurred.2 The elastic recovery of the herbage wafers with different cross sections has a great effect on energy consumption .With increase of the section area of baling chamber ,the elastic recovery ratio and specific work tend to decrease first ,then increase.3 The stress-relaxation curve of herbage compressed directly in different cross areas have the same characteristics .The Rheological models for alfalfa and broken maize corn have been established by means of successive residuals ,which are all Generalized Maxwell models consisted of 3 parallel Maxwell elements ,and the stress-relaxation equation ,the parameter as well as the varying regulation were obtained accordingly.4 The distribution of maximum axial compression force and elastic recovery stress...