Study on the particle breakage of ballast based on a GPU accelerated discrete element method
Breakage of particles will have greatly influence on mechanical behavior of granular material (GM) under external loads, such as ballast, rockfill and sand. The discrete element method (DEM) is one of the most popular methods for simulating GM as each particle is represented on its own. To study breakage mechanism of particle breakage, a cohesive contact mode is developed based on the GPU accelerated DEM code – Blaze-DEM. A database of the 3D geometry model of rock blocks is established based on the 3D scanning method. And an agglomerate describing the rock block with a series of non-overlapping spherical particles is used to build the DEM numerical model of a railway ballast sample, which is used to the DEM oedometric test to study the particles’ breakage characteristics of the sample under external load. Furthermore, to obtain the meso-mechanical parameters used in DEM, a black-analysis method is used based on the laboratory tests of the rock sample. Based on the DEM numerical tests, the particle breakage process and mechanisms of the railway ballast are studied. All results show that the developed code can better used for large scale simulation of the particle breakage analysis of granular material.
Keywords: Discrete element method (DEM), Particle breakage, Graphical processing unit (GPU), Railway ballast, Granular material (GM),