EFFECTS OF CUTTING PARAMETERS ON THE SHEARING PROPERTIES OF OILSEED RAPE (BRASSICA NAPUS L.) SHOOTS IN HARVESTING

Oilseed rape ( Brassica napus L.) shoots are used as an edible nutritious and healthy vegetable. However, there is little information for the effects on cutting parameters on the oilseed rape stalk shearing properties to harvest fresh shoots. This study used the single factor method and response surface methodology (RSM) along with central composite design (CCD) to examine the effects of the blade operating and structural parameters, such as the blade loading velocity, the bevel angle, the oblique angle, and the thickness, on the response variables of ultimate shear stress and specific shear energy. The RSM analysis results demonstrated that the interaction term of blade oblique angle and thickness affect the response variables. Optimized operating and geometry parameters for minimizing response variable values were 195 mm min-1 for loading velocity, 16.4 degrees for bevel angle, 16.3 degrees for oblique angle, and 3.2 mm for thickness. Moreover, under these optimal parameters, the ultimate shear stress and specific shear energy were reduced by 31.37% and 40.95%, respectively, compared to the cutting parameters of the prototype harvester. This study concluded that the appropriate cutting parameters could effectively decrease the shear force and energy requirements, which provided a vital basis for designing and developing the cutting device for the oilseed rape shoots harvester.