Effect of particle size distribution on temperature variation during PBX compaction

To clarify how particle size distribution affects temperature rise and mechanical behavior during the compaction of PBX-3 molding powder, a three-dimensional multi-particle finite element model (MPFEM) was developed under different particle size distribution conditions. The model was used to simulate the densification, particle deformation, contact evolution, and temperature variation of the particle system during uniaxial compaction. The effects of plastic deformation and interparticle friction on energy dissipation and temperature rise were also considered. The results show that the temperature evolution during compaction exhibits distinct stage-dependent characteristics, with a pronounced increase associated with enhanced plastic and frictional dissipation. Particle size distribution significantly affects particle rearrangement, deformation behavior, contact conditions, and the resulting temperature rise. An increase in the friction coefficient further enhances frictional dissipation and consequently promotes temperature increase. Under the particle size ranges and compaction conditions considered in this study, the most pronounced temperature rise occurs for particles within the 0.06–0.14 mm size range. This behavior is mainly attributed to the regulation of particle contact structures and plastic deformation by particle size distribution, which in turn governs energy dissipation and thermal evolution during compaction. These findings provide a numerical basis for understanding and controlling thermal effects during PBX powder compaction.