A New Method for the Generation of Polydisperse DEM Specimens

The mechanical properties of granular materials are closely related to their gradations. In the DEM simulation of granular materials, it is very important to generate a specimen with a reasonable gradation. In this study, a DEM specimen generation method that can take a predefined gradation into account is proposed. The proposed method is based on the probability density function (PDF) and can be easily programmed. The principle and the numerical procedures of the method are firstly presented. Then, it is used to generate a DEM specimen with the gradation of a real coarse material, which is compared with the one generated by a conventional method. The local polydispersity of the DEM specimens generated by the two different methods and their conformity with the real gradation are discussed. The results demonstrate that the grading curve of the specimen generated with the proposed method is more continuous and smooth, and will converge to the target gradation curve when the number of the generated particles increases.