A nonlocal material point method for the simulation of large deformation problems in brittle soils

This paper investigates the implementation of a nonlocal regularisation of the material point method to mitigate mesh-dependency issues for the simulation of large deformation problems in brittle soils. The adopted constitutive description corresponds to a simple elastoplastic model with nonlinear strain softening. A number of benchmark...

Investigation of MPM inaccuracies, contact simulation and robust implementation for geotechnical problems

The material point method (MPM) is a numerical technique which has been demonstrated to be suitable for simulating numerous mechanical problems, particularly large deformation problems, while conserving mass,momentum and energy. MPM discretises material into points and solves the governing equations on a background mesh which discretises the...

On stress oscillation in MPM simulations involving one or two phases

Stress oscillations in the material point method (MPM) are one of the major reasons unrealistic results are obtained. In this paper an investigation of the stress oscillations occurring when using one- and two-phase approaches is performed. Specifically, an axisymmetric benchmark and a two-dimensional plane strain problem are used to demonstrate...

An investigation of stress inaccuracies and proposed solution in the material point method

Stress inaccuracies (oscillations) are one of the main problems in the material point method (MPM), especially when advanced constitutive models are used. The origins of such oscillations are a combination of poor force and stiffness integration, stress recovery inaccuracies, and cell crossing problems. These are caused mainly by the use of...

Compound material point method (CMPM) to improve stress recovery for quasi-static problems

Stress oscillations and inaccuracies are commonly reported in the material point method (MPM). This paper investigates the causes and presents a method to reduce them. The oscillations are shown to result from, at least in part, two distinctly different causes, both originating from the shape function approximations used. The first is due to the...