Study on the detonation reliability of explosive trains with a micro-sized air gap

Air gap thickness significantly affects the detonation reliability of explosive trains. This paper mainly studies the detonation reliability of explosive trains with a micro-sized air gap. First, the detonation process of the JO-9C mild detonation cord initiating the 1.7 g/cm3 JO-11C booster is simulated by the AUTODYN software, and the critical air gap thickness is obtained between 0.32 and 0.40 mm. Second, a test device for explosive trains with adjustable air gap thickness is designed based on the numerical simulation results, and the adjustable step length of the air gap thickness is 0.0625 mm. Finally, a small sample evaluation method that does not depend on the standard deviation of the sensitivity distribution is proposed, and only 86 test samples are needed to verify the detonation reliability of 0.9999 at 0.1 mm air gap thickness. The test device designed and the small sample evaluation method proposed can be referred to for the detonation reliability evaluation of explosive trains with a micro-sized air gap.