Fragmentation of wet agglomerates after normal impact with a flat surface: Experimental study and DEM simulation

The mechanisms that govern the deformation and fragmentation of wet agglomerates upon impact with a solid surface remain inadequately understood. This study aims to investigate the dynamics of wet agglomerates following a normal impact combining an experimental method and discrete element method (DEM) simulations that incorporate a liquid bridge model. Typical dynamical parameters, including damage ratio, capture ratio, dimensionless expansion radius, average expansion kinetic energy, and coordination number, are introduced to characterize the deformation and fragmentation processes of wet agglomerates. The findings reveal that wet agglomerates undergo deformation without disintegration at low impact velocities, while fragmentation occurs at higher velocities. The presence of liquid bridge forces between particles significantly enhances the ability of agglomerates to resist fragmentation. Furthermore, a regime map is established to categorize the behaviors of wet agglomerates upon normal impacts into four distinct categories: minor deformation, minor fragmentation, major fragmentation, and disintegration.