Experimental study of the deformation and breakage of 3D printed agglomerates: Effects of packing density and inter-particle bond strength

Characterization of the mechanical properties of agglomerates is important in order to understand their deformation and breakage. However, research progress has been hampered by limitations in our ability to manufacture reproducible agglomerates with well-controlled and fully characterised mechanical properties. In this paper, we report on the preparation and testing of agglomerates with tuneable properties using 3D printing technology. Two typical agglomerate structures with different packing densities were designed and printed using a PolyJet 3D printer. Each agglomerate consisted of rigid primary particles connected by either rigid or rubber-like inter-particle cylindrical bonds. Compression tests (using speeds in the range 0.02–0.5 mm/s) and drop weight impact tests were carried out to investigate the effect of bond material and strain rate on mechanical properties of the agglomerates. The results show that strain rate affects their deformation and breakage significantly, and breakage patterns of the two structures are different under uniaxial compression and impact test conditions. These results demonstrate the broad utility of 3D printed agglomerates as ideal “test” agglomerates for a range of breakage studies, including validating computer simulations of DEM breakage.