Large deformation modeling in soil-tillage tool interaction using advanced 3D nonlinear finite element approach

This paper aims to introduce a finite element model to investigate the performance of bent leg (BL) plow and investigate the performance of new design as compared to a conventional one using finite element method approach (FEM).The difference between the modified and conventional BL plows is the direction of angle between the projection of cutting blade on horizontal plane normal to plow shank and the line perpendicular to the plow shank in the same plane. The effects of BL plow geometry on plow performance for both plows were studied and the results were verified experimentally. Conventional (B1), and modified (B2) designs of BL plow were modeled at three rake angles (R1= 7.5°, R2= 15° and R3= 22.5°), therefore a total six treatments were considered for both theoretical and experimental studies. A three dimensional non linear finite element model was developed using appropriate FEM software (ANSYS 8.1). The soil media was considered as elastic-perfectly plastic with Drucker-Prager material model. Soil meshing, contact elements and soil frictional properties were updated after each incremental time step. Variation of draft force as calculated by the FEM model indicates that the minimum and maximum draft forces correspond to B2R2 and B1R3 treatments respectively. The experimental results of draft force were in good agreement with predicted data.