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

Abstract

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.

A Combustion Model for Explosive Charge Affected by a Bottom Gap in the Launch Environment

“…Qiang et al [21] used a numerical model of the small-scale gap test to obtain the critical gas thickness for the detonation reaction of a solid propellant. Cheng et al [22] simulated the detonation process of explosive trains with a micro-sized air gap and concluded that the critical air gap thickness ranges from 0.32-0.40 mm. Following a series of underwater experiments, Xiao et al [23] concluded that COM B explosive charge can explode and has a peak pressure of 1600 MPa during launch with a bottom gap of 0.38 mm.…”