The discrete element method is used to investigate the high-velocity compaction process with additional piston supports known as relaxation assists. It is shown that by incorporating the relaxation assists in the piston-die assembly, particles can be better locked during the compaction process. The simulation results reveal that relaxation assists offer; smooth compaction during loading stage, prevention of the particle separation during unloading stage and conversion of higher kinetic energy of hammer into particle deformation. Finally, the influences of various loading elements on compaction process and effects of presence of adhesion during unloading stage are investigated. The results support the findings of experimental work. (C) 2011 Elsevier B.V. All rights reserved.