Résumé
Purpose. Deformability of highly soft particles such as many pharmaceutical and food products under low confining pressure allows for high packing fractions above the jamming state of hard particles without rupture. Here, a combination of particle rearrangements and particle shape change controls the rheological properties of soft particulate materials. Using a numerical approach, we investigate the compaction of assemblies of soft particles.Methods. The numerical technique is based on the Material Point Method (MPM) allowing accounting a large class of mechanical behavior (elastic, plastic...) of individual particles. Coupling the MPM with the Contact Dynamics method makes it possible to deal with contact interactions between particles [1].Results and Conclusions. We investigate the compaction of assemblies of elastic and plastic particles. Compressibility rates ranging from fully compressible to incompressible particles are considered for elastic particles. We show that the uniaxial stress declines as the particle compressibility decreases, and the packing can deform considerably. For the plastic particles, it is observed that one needs less applied stress to achieve high packing fraction when the plastic hardening is small. Moreover, the predictive models, relating the applied stress to the packing fraction, are proposed for the compaction of elastic and plastic particles. These models can fit well the simulation results. Furthermore, for both cases, the evolution of the coordination number is related to the packing fraction by a power-law function beyond jamming transition.References.[1] Nezamabadi et al., Computer Physics Communications, 237: 17-25, 2019.