Shape analysis of sand particles based on Fourier descriptors

Abstract

The particle shape will greatly influence the mechanical behavior of geotechnical materials. For a specific material, e. g. sand particle, it remains an open question how to provide a comprehensive quantitative information about the particle shape. While Fourier descriptors, as a sequence of good shape descriptors, are well addressed in the literature, approaches mainly aim at pattern recognition in the field of computer vision. In this paper, Fourier descriptors are used to analyze particle shape of geotechnical material. 600 sand particles are collected from Hutuo river, the main water resource of Shijiazhuang County, Hebei Province. Several shape descriptors, elongation, circularity, convexity, and roughness, are identified and further analyzed statistically. A functional relationship between Fourier descriptors Dk and k, the frequency of the kth components is proved to exist. Moreover, the relationship between shape descriptors and Fourier descriptors is investigated in a correlation analysis. The elongation is strongly correlated to Fourier descriptors.