Numerical and Constitutive Analysis of Granular Column Collapse Experiments Under Reduced-Gravity Conditions

The research on granular column collapse under various gravity levels is of great significance for the study of granular rheology and its applications in reduced-gravity space engineering. We firstly reviewed a rare experimental investigation that observed a gravity-related run-out distance of the granular column collapse in this paper. To identify the origin of the gravity-related run-out distance, a unified constitutive model was used to simulate the behavior of granular materials in these experiments based on a large deformation numerical method, the smoothed particle hydrodynamics (SPH). The parameters of this constitutive model were also discussed. Numerical simulations can reproduce the run-out distances that positively correlate with the gravity level, above 0.03 g in particular. Based on the numerical and constitutive analysis, this gravity-related runout distance is attributed to the combined influence of gravity-induced pressure and shear strain rate levels on granular flow.