Repozytorium publikacji - Politechnika Gdańska

Discrete Element Method is a numerical method suitable for modeling geotechnical problems concerning granular media. In most cases simple forms of grains, like discs or spheres, are used. But these shapes are capable of soil behavior modeling up to a certain point only, they cannot reflect all of the features of the medium (large shear resistance and large volumetric change). In order to reflect the complex behavior of the real soil either other grain forms or numerical parameters have to be used. The question of shape influence has not been fully understood yet. The aim of the present paper is to study the influence of the grains shape on the mechanical behavior of granular assemblies, grains convexity in particular. Two groups of grains are compared: convex irregular polygons, and non-convex clumps of three overlapping disks. These shapes are chosen because of the similarity of global shape. A large number of shape variants was used in both groups and a shape parameter a is introduced. The samples were loaded in a vertical compression test simulated with a 2D DEM code. The results are investigated on both macro- and microscopic levels. Evident differences in the behavior of two particle groups are studied and discussed: convexity influence on macroscopic friction angles values, different mechanisms of shear localization. It appears that assemblies of clumps lead to shear band forming while assemblies of polygons lead to diffused rupture mechanism. This work was done as a part of CEGEO research project(1).

Autorzy

• dr inż. Krzysztof Szarf link otwiera się w nowej karcie ,
• Gaël Combe,
• Pascal Villard