Effect of granular shape on angle of internal friction of binary granular system

The study of angle of internal friction (Phi(I)) is widely prevalent due to its importance in science and engineering, and yet the quantitative description concerning the effect of granular shape on the Phi(I) is few. In our study, the influence of granular shape on the Phi(I) of various binary granular systems was investigated theoretically and experimentally with a Freeman FT4 Powder Rheometer. The results show that the variation amplitude of tangent Phi(I) (Delta tan Phi(I)) exhibits a linear relation with the related particle physical properties. Our findings show that three regions have been divided for various binary granular systems based on their magnitude of aspect ratio, and there exists a powder function between Delta tan Phi(I) and granular shape factors. On this basis, an integrated model has been proposed to describe the quantitative relationship between angle of internal friction and granular shape factor, which agrees well with the experimental data. (C) 2015 Elsevier Ltd. All rights reserved.