Tractor drawn duckfoot cultivator is the most popular equipment being manufactured by the small scale manufacturers and adopted by the farmers of Madhya Pradesh. Almost all tractor owner farmers owns it. While using cultivator, farmers time and again come across problem of bending of shanks, encountered mainly due to improper design, use of non-appropriate material and manufacturing process. Finite element analysis was done to study the behaviour of shanks with respect to their shape. The objectives were to analyze the stress distribution over different shapes of shanks, to analyze the displacement behaviour and to determine which type of shank is most efficient for performance under specified conditions of operation. Dimensions of all the shanks were recorded and soft models of all these shanks were prepared to original shape and dimensions using 3-D CAD software CATIA. The draft (horizontal force) acting on shanks during field operation is the main factor causing bending in shanks. To study the effect of lead angle on bending, shanks with lead angle of 0, 8, 16 and 24° were also prepared. All the solid models were assigned the material properties what mild steel possesses. Modulus of elasticity, yield strength and Poissions ratio were taken as 2 X1011N/m2, 2.5 X108 N/m2 and 0.266, respectively. The required force (draft) for finite element analysis was worked out to be 4000 N by conducting field operation. It was observed that the bending behaviour of shanks is influenced by lead angle. The shank with 0°Lead angle gave least displacement of 0.586 mm. It was observed to be increasing with increasing lead angle. The displacement values for 8°, 16° and 24° were found to be 0.592, 0.608 and 0.624 mm, respectively. These displacement values were 40 to 43% lower in comparison to double bend shanks largely being used by the farmers. Double bend shanks also showed max stresses of 92 Mpa.

Keywords: Shanks, modulus of elasticity, tractors, drawn duckfoot cultivator.