Research on the high velocity compaction process of iron-based powder based on the DEM

In order to further study the dynamic response of granular systems under impact loading, this paper establishes an SHPB test model of metal powder based on the discrete element method (DEM) of particles using PFC3D software. The High Velocity Compaction (HVC) process is simulated by numerical simulation. The distribution and change rules of particle movement are observed from different angles; the change rules of particle normal velocities at different positions in the particle sample are analyzed; the formation process of force chains under impact is observed; and the change rules of contact forces between particles at different positions are analyzed. From the motion law of the particles, the loading end of the specimen (right side) first obtains a larger initial velocity in the initial stage of loading. From the stress wave propagation analysis, there is a significant stress shear band in the compaction process. From the normal velocity analysis of particles at different locations, the disturbance along the loading direction decays layer by layer, and the decay speed in the outer region near the mold wall is higher than that in the center region. From the formation of inter-particle force chains, the incident wave can form a precursor wave, as the particles are under the action of impact load. Through the change process of the contact force of the particles, the particles will have many impacts during impact loading, and the vibration amplitude will decrease with time. This study highlights the novelty of employing a fully coupled three-dimensional DEM-SHPB modeling framework, which provides a more detailed meso-scale understanding of particle dynamics and improves upon previous approaches to high-velocity powder compaction.