Effect of Velocity and Blade Type on Shearing Forces for Two Varieties of Sugar Cane in Southern Khuzestan Province

Crops and agricultural products are subject to natural loading during growth. Different mechanical forces are also exerted on them during harvest. One product, sugar cane, experiences large shear forces are during harvest. An examination of the crop properties and machine parameters of sugar cane are necessary to develop appropriate cutting tools and the optimization and design of harvesting machines. The determination of such physical properties as diameter, moisture content, bulk density and mass per unit length is indispensable to this process. Mechanical properties related to cutting, such as maximum cutting force and strength, required energy and specific energy required for cutting are important. For this research, two experimental samples of sugar cane stalk (CP57, CP69) were collected from Amirkabir Research Farm in southern Khuzestan province. The samples were transported to the laboratory while maintaining the moisture content as constant as possible. The stalks were tested under quasi-static conditions using twotypes of blades (serrated and smooth) at three speeds (0.2, 0.5 and 1.35 m/min). The resulting data were analyzed using MSTATC and SPSS software. The effect of the variety on maximum cutting force was not significant, but cutting strength was observed to be significant at the 1% level. The effect of speed change on maximum cutting force was also significant at the 1% level. The effect of blade type on both maximum cutting force and cutting strength was significant at the 1% level. Increasing the speed from 0.2 to 0.5 and then to 1.35 m/min, especially using the smooth blade, increased the efficiency of cutting. However, increasing the speed from 0.5 to 1.35 m/min using the serrated blade increased cutting strength and energy. The serrated blade, at low speeds, was observed to require lower energy. Serration reduced energy consumption and lowered the required cutting strength because of adequate primary penetration of the blade into shell of the stalk, and the reduction of compression time.