Large strain finite element analysis of sand: model, algorithm and application to numerical simulation of tire-sand interaction

Based on a review of several existing models for the elastic responses of geomaterials, a new nonlinear elastic law is suggested. A fully implicit return mapping algorithm for non-associative elastoplastic models of the geomaterials is presented within the regime of large strains. This algorithm is formulated in the principal axes. Algorithmic tangent moduli are derived. A modified critical state model in conjunction with the new nonlinear elastic law is implemented into the general purpose finite element software MARC, using the proposed algorithm. Furthermore. the tire-sand interaction is numerically simulated, employing the modified model and the algorithm. (C) 1999 Elsevier Science Ltd. All rights reserved.