The collapse test is a simple experimental test to evaluate the flowability of materials and an excellent benchmark for the numerical modelling community for validating numerical models.
Several collapse tests were carried out in our laboratory and modelled with DEM, DEM-PFV and SPH.
Experimental tests
Experimental test campaigns were performed in quasi-2D conditions (column) as well as in axial-symmetric conditions with different granular materials, water contents and aspect ratios.
For glass balls see
For angular carbonate particles and glass balls see
For mixture of cohesive and granular materials see
DEM numerical simulations
DEM is straightforward for modelling glass balls in dry and wet conditions.
A capillary force at the contact between grains was implemented in DEM
These are some results showing the difference between the dry (Figure 1) and wet conditions (Figure 2).