3D printing-aided numerical study of particle shape effect on behaviours of dry granular flows interacting with rigid barriers

Particle shape plays a crucial role in determining the mobility and impact characteristics of granular flows, yet analyses of the effects of particle shape are rare. In this study, three-dimensional (3D) printing technology is used to create rock-like materials with varying shapes. This approach enables the precise control of mechanical properties other than particle shape, eliminating potential confounding factors. Then, we construct particle flow samples with distinct shape characteristics, quantitatively assessing their shape variations according to their overall regularity (OR). Flume experiments are conducted, with the findings used to calibrate a discrete element numerical model. By integrating the numerical simulations and experimental data, we systematically investigate the flow, impact, and deposition behaviours of granular flows under diverse flume inclinations considering the influence of particle shape. The results demonstrate that the mobility and destructiveness of granular flows increases with higher OR values and steeper flume inclinations. The transition from pile-up to runup deposition is primarily controlled by the flume inclination, while within specific inclination ranges, changes in OR can also induce deposition mechanism transition. This study provides substantial insights into interactions between granular flows and protection structures, emphasizing the significance of particle shape and terrain characteristics within a source area.