Design and Experimental Study on a Corn Picking Device Based on the Fracture Mechanics of Corn Peduncle

Highlights This study designed a corn ear picking device to reduce grain loss and corn header power consumption. The fracture force of corn peduncles under different deflection angles was studied as the basis of the design. The working parameters were optimized through an orthogonal experiment. Abstract. In corn ear picking, the corn peduncles are fractured under pure tensile forces. The large force demands in the fracture brought severe grain loss, an enormous instantaneous load, and high power consumption in the corn harvest. In this paper, the fracture behavior of the corn peduncles under different tensile orientations was studied. It showed the fracture force of corn peduncle could be reduced by more than 80% when its fracture mode transformed from tensile fracture to bending fracture as long as the corn ear was deflected to the critical angle of 55°. Based on this, a corn picking device was designed to reduce peduncle fracture force by deflecting corn ears to the critical angle. The optimal parameters of the designed corn picking device were determined as follows: the diameter of the snapping rollers was 20 mm, the rotating speed of the stalk rolls was 700 rpm, and the inclination angle of the corn picking unit was 28.3°. A comparative test between the designed corn picking device and a commonly used corn picking device was performed. It showed the designed corn picking device could reduce grain loss, average power consumption, and peak power. This study will provide a theoretical basis and design reference for corn harvester design to reduce grain loss and power consumption. Keywords: Corn ear picking, Corn harvest, Corn harvester header, Fracture force, Fracture mechanics, Grain loss, Power consumption.