Automatic step size correction for non‐associated plasticity problems

Abstract

AbstractThe finite element method is used in calculating accurate collapse loads. The behaviour of granular materials is described by the non‐associated Mohr–Coulomb model. The load–displacement path is traced up to and beyond limit points using an accelerated initial stiffness method. The convergence properties of this method are examined, both for associated and non‐associated plasticity.Step sizes in the incremental iterative procedure are adapted during the iteration process, depending on an estimated number of iterations. The automatic step size control thus obtained proves to be robust and particularly appropriate for non‐associated plasticity. Some soil collapse calculations are discussed to demonstrate the practical application of the method.