Improved method for generating sand assembly with wide range of aspect ratios and angularities based on insights gained from comparative study of existing techniques

Abstract

The generation of realistic sand assemblies with a wide range of particle shapes is important for investigating the influence of particle shape on the microscale and macroscale mechanical behaviors of sands using the discrete element method. The major contribution of this study is the development of an improved technique for such assemblies. The method generates sand assemblies with a wide range of aspect ratios and angularities and retains the particle size effects and major morphological characteristics of the original particles. First, based on the insights gained from a comparative study of existing techniques, a method that integrates principal component analysis (PCA) with coefficient standardization is selected as the basic framework for particle generation. Second, by expanding the spherical harmonics (SHs) of the compensation radii between particles and their circumscribed super-ellipsoid surfaces, a new method that can extract the aspect ratio characteristics of sand particles is proposed for particle reconstruction. Finally, a method integrating the SH expansion of the compensation radius, PCA, and coefficient standardization is formulated and demonstrated to be efficient in generating sand assemblies with a wide range of aspect ratios and angularities.