Generating realistic 3D sand particles using Fourier descriptors

This paper presents a novel method of generation of random realistic sand grains for use in three dimensional (3D) DEM simulations. Based on the concept of Fourier descriptors for sand grains proposed recently by the same authors, we first randomly generate three 2D contours of cross-section for a real sand particle in three orthogonal planes, and then develop a morphing technique to construct the external 3D surface of the particle to match these cross-sections. The proposed method is examined by application to the generation of six sands reported in the literature using the Fourier spectrums available for these sands. We show that with a proper correction on the smoothness and roundness of the orthogonal projection calibrated from the six sands, the method can generate fairly consistent results as compared to the real sands. Further validation of the proposed method on another three sands shows satisfactory performance. The advantages and limitations of the method, as well as relevant future applications of the work to granular material modelling are discussed.