MOLECULAR DYNAMICS SIMULATIONS OF HIGH VELOCITY SHOCK COMPRESSED TNT

We simulate the shock compression behavior of TNT with ReaxFF-MD. When shock compression is complete, all of the TNT molecules are decomposed, and when volume compression is up to the 40% of original volume, pressure of the system reaches a peak. Close behind is rarefaction wave reverse stretching the compressed energetic materials and leading to a large number of atoms or molecules group splash to the downstream, pressure begin to unload at the same time. Density and particle wave velocity profile show a greater density in the compressed region, and the particles in a stationary state, but sharp velocity gradient in the region of compression wave. In the earlier chemical characteristics, TNT molecules shed the H, O atoms under the effect of shock compression, and then the residues aggregate to the larger clusters, and this phase associated with translational-vibrational relaxation processes. The rotational mode is subsequently transferred into vibrational modes with a time scale of 0.5 ps. Fragment analysis shows that a large number of C—H, O＝N bonds rupture to form the OH, H₂, H₂O, N₂ groups and parts of H, O atoms are free in the system. The molar mass of the carbon-containing clusters under the joint actions of compressional wave ahead and rear compression is accumulating gradually from the analysis. Atomic ratio in the carbon-containing clusters tends to balance (O/C=0.680, H/C=0.410, N/C=0.284), but less than the ratio in the initial structure.