Relationship Between Residual Contact Force and Residual Stress in Granular Packings Subject to Partial Loading and Unloading

Abstract:

Contact forces acted on representative pentagons were achieved through fringe analysis based on the photoelastic experiment of pentagons subject to loading and unloading. The evolution of contact forces reveal that residual contact force lies remarkably in contacts between deepburied pentagons while barely in contacts between superficial pentagons during unloading. Photoelastic experiment was reproduced via discrete element simulation, and the comparison of both interparticle contact force between photoelastic test and numerical test demonstrates that the numerical model is reasonable. Besides, the stress evolution of pentagon packings during loading and unloading was studied. The results indicate that the spatial distributions of stress and force chain, residual stress and residual contact force are consistent.

Key words:granular packings; loading and unloading; residual contact force; residual stress; photoelastic experiment; discrete element method