Breakage of fractal agglomerates

Breakage behavior of fractal agglomerates as a function of impact velocity and surface energy was investigated using discrete element method (DEM). Agglomerates with fractal dimensions (D-f) ranging from about 2.0 to 2.8 were produced by letting primary particles having random initial velocities agglomerate under a centripetal force. The simulation results show that the damage ratio (D-m), defined as the ratio of broken interparticle contacts to the initial total contacts, decreases with increasing fractal dimension in the range between 2.0 and 2.6, which can be explained by the increased mechanical strength with increasing fractal dimension. Previously introduced Weber number (We) based correlation for damage ratio is generalized by incorporating the fractal dimension: D-m = B(We/D(2)f)(alpha), where B and alpha depend exponentially and linearly on Weber number, respectively. Visualization of impact process illustrates the feature of ductile fracture of fractal agglomerates irrespective of fractal dimensions. (C) 2016 Elsevier Ltd. All rights reserved.