Influence of Knife Bevel Angle, Rate of Loading and Stalk Section on Some Engineering Parameters of Lilium Stalk

摘要

Some physical and mechanical property testing of main stalks of Lilium was conducted to provide information for future automatic machine design. Shear, compression and bending properties of Lilium stalks were determined with using a universal testing machine. The experiments were conducted at three rate of loading levels from 30 to 50 mm/min, three knife bevel angle levels from 30 to 60 degree and at two levels the stalk; upper and lower. The results showed that all the mentioned above parameters had significant effect on the measured mechanical properties (P<0.01). In all three loading rate, an increasing the shear strength and specific cutting energy were observed as the knife bevel angle increased. The highest compression strength and specific compressing energy were 6.86 MPa and 21.34 mJ/mm2 at the lower level, while the lowest compression strength and specific compressing energy were 2.90 MPa and 10.69 mJ/mm2 at the upper level. As the loading rate of the stalk increased, the bending strength decreased, indicating a reduction in the brittleness of the stalk. The average values for modulus of elasticity were found to be 23.48 and 15.96 MPa for stalk regions of upper and lower, respectively.