Relevance of a predetermined rupture line for modelling soil-tool interactions using the finite element method

摘要

Simulations were performed in two dimensions (2-D) to study the relevance of using a predetermined soil rupture line to model soil-tool interactions using the Finite Element Method (FEM). Five rupture criteria were compared: conventional (no ruptureline), friction, stresses at the crack tip, crack spacing, and crack distance-time. The soil deviatoric stress and displacement revealed that stresses and friction criteria were not adequate with the cohesionless Cam clay model used because of the discontinuity between the top and sub soils. The 3 other criteria had similar rupture zones, stress contours, and tool forces. Elements at the tool tip were less distorted when a rupture line was included to help model continuous tool displacement. However, the rupture zone at the tool tip is not necessarily uniform and horizontal. The conventional meshing is much simpler to generate, requires 25-50% less computation time, is also applicable in 3-D with the commercial FEM package ABAQUS, and the results aresimilar for small tool displacement in the soil.