SIMULATION AND TEST OF CUTTING MECHANICAL CHARACTERISTICS OF MILLET STALK BASED ON ANSYS/LS-DYNA

Abstract

In order to find the variations of mechanical properties of millet stalk during dynamic cutting, a three-dimensional model of cutting parts and a double-layer flexible model of millet stalk were established in this study. The mechanical cutting properties of millet stalk at different cutting speeds and blade oblique angles were investigated based on ANSYS/LS-DYNA, while the verification tests were carried out based on the self-made cutting test bench. Simulation results showed that the maximum Von Mises stress was concentrated on the contact point of the stalk and the moving blade. The maximum Von Mises stress of stalk during extrusion, cutting, and after cutting were 60.03 MPa, 60.72 MPa, and 39.87 MPa, respectively, and the cutting energy of stalk epidermal tissue was greater than that of inner tissue. The cutting stress and the unit area cutting energy decreased first and changed steadily as cutting speed was increased when the cutting speed was 0.5-1.5 m/s. When the blade oblique angle was 0°-48°, the cutting stress decreased as the blade oblique angle was increased, while the unit area cutting energy decreased first and then increased. Verification tests showed that the cutting speed and the blade oblique angle had significant effects on the cutting mechanical properties (P < 0.05), which was consistent with the simulation test results. Research results can be used to optimize the cutting parameters of millet stalk