The effect of particle shape on the collapse characteristics of granular columns via the DEM

Granular flows that are composed of coarse solid particles are common in catastrophic events, such as landslides, rock avalanches, pyroclastic flows, or even turbidity currents. Understanding their complex dynamics is thus a key concern for risk assessment. The goal of the analyses in this study is to investigate the effects of particle shape on two-dimensional granular column collapses via the discrete element method (DEM). Specifically, three different particle shape types are constructed through three shape parameters (i.e., Sphericity S, Angularity a and roughness k), the granular column mobility R* changes regularly with the evolution of the shape parameters at a specific aspect ratio. We investigate the effects of particle shape on the collapse of granular columns using a method that first selects an extreme shape and then transitions through a series shape evolution. Using this method, particle shape is shown to have an important effect on deposition morphology, energy evolution and the mechanical coordination number. Furthermore, the shape parameters that have the strongest impacts on granular column collapse are shown to be S and a, which can be used as macroscale factors to describe particle shape. Also, k, which is a microscale factor that describes the particle surface, is shown to have a weaker influence. This study provides useful insights into the fluidity response of particle shape on granular column collapse. (c) 2023 The Society of Powder Technology Japan. Published by Elsevier BV and The Society of Powder Technology Japan. All rights reserved.

Automated summary

This study investigates the effects of particle shape on the collapse of granular columns using the discrete element method. The results show that particle shape has a significant impact on deposition morphology, energy evolution, and mechanical coordination number. Sphericity and angularity are identified as the most important macroscale factors, while roughness has a weaker microscale influence.