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

Abstract

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/mm at the lower level, while the lowest 2 compression strength and specific compressing energy were 2.90 MPa and 10.69 mJ/mm 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.

Research on Biomechanical Properties of Laver (Porphyra yezoensis Ueda) for Mechanical Harvesting and Postharvest Transportation

“…The laver and rose flower stems were compressed at low cutting rates while resisting shearing by the knife. However, at high cutting rates, the elastic walls of the cells did not have enough time to transmit shear forces to the viscous fluid inside the cells, resulting in a decrease in shear strength [42,43]. The same findings were also reported by Hassan-Beygi for the shear strength of saffron stalks [41].…”

“…Meanwhile, several studies have also reported the effect of loading rate on mechanical properties of agricultural crops. The crops included saffron [41], sorghum [42] and lilium [43]. In general, the biomechanical properties of algae, plant stem stalks, and leaves are strongly influenced by factors such as origin and harvest times.…”

Design of Structural Parameters of Cutters for Tea Harvest Based on Biomimetic Methodology

“…Commonly used cutters in tea pluckers include the reciprocating cutter, disk cutter, and flail-type cutter. Compared with the disk and flail-type cutters, the reciprocating cutter has a simpler structure and a wider range of adaptations [6][7][8]. Besides, it is important to optimize the structural parameters of the reciprocating cutter to improve its cutting performance.…”