Experiments on Mechanical Properties of Sugarcane Leaf Sheath

Abstract

To study the leaf fracture mechanism in the leaf-stripping process for the whole stalk sugarcane harvester, information must be available about some mechanical strength. In this work, experimental results are presented on longitudinal tensile strength (LTS), transverse tensile strength (TTS) and punch-and-die shear strength (PSS) of sugarcane leaf sheath, as a function of growth periods, node along the stalk and moisture content (w.b.). The fundamental experiments including longitudinal tensile tests, transverse tensile tests and punch-and-die tests were conducted with special fixtures designed based on the characteristics of sugarcane leaf sheath, and the WDE-500N Universal tester (Grandtry Co.,Ltd. China). The results showed that the influences of the node along the stalk and growth periods on values of the LTS, TTS and PSS were all boiled down to the effect of moisture content (w.b.). The LTS, TTS and PSS values of leaf sheath on the node1, node2, node3 and node4 from the top to the root of the stalk at moisture contents of higher than 45% and lower than 70%, are not significantly different from each other, while on the node5, node6 and below to the root with the moisture contents ranged from 10% to 20%, they behave no significantly different, however, the values of the three measurements at moisture content 45% were significantly higher than that at moisture content 20% (w.b.) respectively. The maximum values of the LTS, TTS and PSS in the period of sugarcane harvested equaled 28.19MPa, 0.90MPa and 7.13MPa, respectively.