Effect of gravity on the strength of granular matter

Quantifying the effect of reduced gravity on the behavior of granular matter is essential to understanding the evolution of planetary morphology, and will likely affect the design of future extraterrestrial habitats. Yet, despite recent research efforts, the effect of reduced gravity/confining pressure on strength remains undetermined with scarce results ranging from no effect to opposing trends. In this study we employ high-fidelity discrete element simulations (DEM) of passive failure experiments to measure the influence of gravity on the peak and steady state friction angle, and the angle of repose of sand. The results are compared against recently reported physical experiments, lending the latter support based on micromechanical information, that is unattainable experimentally. We find that the friction angles experience a small increase with decreasing gravity, while the angle of repose remains almost constant.