Discrete Element Modeling for Two-dimensional Irregularly-shaped Particles

In order to obtain a precise modeling method that would be comparable with experimental results, the specification of grains such as form, size, elasticity, plasticity should be modeled carefully. Since the shape of the grain affects tremendously the mechanical behavior of total grains like shear resistance, the appropriate modeling of the grain shape is considered to be very important. In most cases of modeling that have been applied so far, the grain form is either circular, elliptical, polygonal modeled which none of them is a direct model of the irregular shape of the grain, hence will not project the mechanical behavior as expected. So, it seems to be worthy that direct modeling of grains with irregular shapes be accomplished. The method that is employed in this paper, is in fact a direct modeling of grain’s shape. In this method, the real shape of grain is modeled by combining arbitrary number of overlapping circular elements which are connected to each other in a rigid way. In order to measure the effects of grains shape on mechanical properties of granular soils three types of grains, high angular grains, medium angular grains and round grains are considered where several biaxial tests are performed on assemblies with each of grain types. The results emphasize that the angularity of grains is considerably affecting the behavior of soil. Also, the results are compared against experimental measurements in a qualitative manner which show a reasonable conformity.