Modeling the Collapse of Granular Material on a Rigid Wall with Material Point Method (MPM)

The material point method (MPM) is a numerical technique to modeling the large deformation and interaction between different phases of materials. MPM combines the best aspects of both Lagrangian and Eulerian formulations while avoiding some shortcomings of them. In MPM a body is modeled with the particles which carry all physical properties of the continuum such as mass, momentum, strains and stresses. The background mesh is used to solving the momentum equation. In the first phase, information is mapped from particles to nodes. In the second phase, momentum equations are solved for the nodes, and then the updated nodes are mapped to the particles to updating their positions and velocities. In the third phase the grid is reset. In numerical simulation of granular flows, large deformations and interactions between grain boundaries and buildings lead to the complexity in the structural behavior of the material and, as a result, the complexity of the simulations. From different numerical techniques, the material point method is a suitable method for simulating such problems. In this study, the problem of the collapse of a column of granular material on a rigid wall was simulated in two dimensions through material point method. The surface profile and displacement of the front were compared with the laboratory results which a good accordance is observed between them. The results show that the ratio of the initial column plays an important role in the development of granular mass.