Exploring whether the simplified-shaped fines with rolling resistance can replace the real-shaped fines in sand-gravel mixture models

Abstract

Taking particle shapes into consideration is an inevitable trend in simulating geotechnical granular matters. However, the computational costs involving irregular shapes are considerable, especially for granular mixtures with abundant particles. To improve computational efficiency, the shapes of some particles, e.g., fine particles, are often simplified, yet the simplification may distort simulation results. This short communication investigates the substitution effect of simplified particles with rolling resistance on real-shaped fine particles. This is achieved by simulating confined compaction tests of mixture models with different fine particles. The contact parameters in models were calibrated and the reliabilities of models were verified by a series of physical tests. The results show that the macroscopic deformation and mesoscopic particle motions in simplified models with rolling resistance are perfectly close to those in the models with real-shaped fines, especially when the size ratio exceeds 7. Due to the different sources of rolling resistance, however, applying rolling resistance inevitably causes a difference in kinetic energy.