Experimental and Numerical Study of Shock Initiation of Covered TNT by Near-Field Shock Wave

In this study we analyzed the shock initiation process of covered TNT using experiments and LS-DYNA3D to study the damage effect of the near-field strong shock wave on the covered charge. We obtained the critical thickness of the covered plate for detonating TNT during contact explosion and the sympathetic detonation distance of the covered TNT during non-contact explosion and the relation between the covered plate thickness and the distance of the explosion using the non-linear least square method. The results show that the numerical simulation results accord well with the experimental results. The sympathetic detonation distance of the covered-pressed TNT in non-contact explosion ranges from 12-15 mm when the thickness of the 45 steel covered plate is 3 mm. The critical thickness of the covered plate is between 20 and 23 mm for the pressed TNT ignited by contact explosion. The sympathetic detonation distance of the non-contact explosion decreases as the covered plate thickness increases. Without a covered plate, the sympathetic detonation distance is 79 mm. When the thickness of the covered plate increases from 1 mm to 5 mm, the sympathetic detonation distance reduces from 51 mm to 1.5 mm. The thickness of the covered plate is of great importance for the protection against shock waves.