Effects of gap on the explosive loading process of tin

To analyse the effect of gaps on the explosive loading process, we carried out an experiment by using high explosive to genarate a detonation impact on a tin sample through a piece of steel and tested the experimental results with a numerical simulation. Then, we explored variation of impacts due to different gap sizes with further numerical studies. The research shows that gaps of even sub-milimeter can emerge an obvious influence on the experimental results. The gap between the tin sample and the steel layer will lead to a stronger reflection of shock wave on the gap surface than that of the case with no gap, and the reflective rarefaction wave will reflect again at the interface between the steel layer and the high explosive to form a strong subsequent compression shock wave, which will lead to the significant increase of the loading pressure on the tin sample. On the other hand, the gap between the metal layer and the high explosive will lead to a certain extent decrease in loading pressure due to pressure release. Compared with the gap between metal layer and high explosive, the gap between tin sample and steel layer has a more serious effect on loading process. In addition, with the increase of gap size, the variation trend of gap effect is also different in the two cases.