Application of the Drucker-Prager elastic-perfectly plastic material model for performing finite element analyses of deep tillage

摘要

The possibility of conducting a non-linear, three-dimensional, finite element analysis of soil cutting process by medium-deep subsoiler based upon the Drucker-Prager elastic-perfectly plastic material model was investigated. The mathematical construction of the Drucker-Prager model was presented. The material nonlinearity of soil was dealt with using an incremental technique. Inside each step the Newton-Raphson iteration method was utilised. While the geometrical nonlinearity was solved by using either the small strain assumption or the updated Lagrange formulation of large displacement. The finite element predictions of subsoiler draught force as well as surface soil failure dimensions agreed well with those measured in a soil bin. An optimal subsoiler design was figured out, which required the lowest draught and developed a good soil loosening quality estimated as soil volume change.