The influence of particle shape for granular media: A fourier-shape-descriptor-based micromechanical study

摘要

Particle shape is known to affect the overall behavior of granular media significantly. It remains a great challenge to accurately characterize the shape of particles and incorporate its effects into the modeling of granular media in a quantifiable and verifiable manner. A micromechanical study based on 2D Discrete Element Method is presented in this paper to investigate the effect of particle shape irregularities on the granular responses. Novel in the study is the use of Fourier shape descriptors in the characterization of irregular particle shape based on statistical analysis of digital grain images obtained experimentally. We generate virtual irregularly and randomly shaped granular grains and introduce them into discrete element method for simulations of shear tests. The influences of irregular particle shape on the macroscopic stress-strain response, fabric anisotropy evolution, particle anti-rotation effect are carefully investigated and discussed. It is demonstrated that the shape effect has to be an important part in characterizing the micromechanics of granular media.