Identification of Pyrotechnic Shock Sources for Shear Type Explosive Bolt

Abstract

To identify the shock generated sources of shear type explosive bolt, five kinds of explosive bolts with different states, including high preload, low preload, no preload, no piston shear, and only propellant combustion, were designed. The decoupling of four kinds of shock sources, including the collision of propellant combustion, piston shear weak surface, end of piston stroke, and preload release, was realized. Their acceleration responses at 15 cm from the shock source center on 60 cm × 60 cm × 1 cm equivalent aluminum plate were measured by using the piezoresistive accelerometer. On this account, the relative contribution values along with frequency and the mean relative values without regard to frequency of various sources were calculated in high and low preload. Results show that the characteristics of different shock sources are different, and the shock induced by propellant combustion is mainly caused by high frequency, while piston shear and piston impact are concentrated in medium and low frequency. In the high preload condition, the preload release is major contributor to the overall shock response output, accounting for approximately 57.51%, while the contributions of the three shock sources of propellant combustion, piston shear, and piston impact are equivalent, but they are significant contributors in the low preload condition. This study provides design reference to reduce the pyrotechnic shock of shear type explosive bolt.

Numerical Study on the Explosive Separation of Pyrotechnic Cutter

“…All of the material structural parameters were from the AUTODYN material library, and their specific values are listed in Tables 2-5 [19][20][21][22].…”

Influence of multiple structural parameters on buffer performance of a thin‐walled circular tube based on the coupling modeling technique

“…Reducing the energetic material mass is acknowledged as one of the most effective ways, but this solution leads to performance degradation of the gas generator. 12,13 Some investigations suggested using the method of absorbing shock by utilizing honeycomb materials with high shock resistance, 14,15 and other investigations 16 confirmed that honeycomb composites had superior buffer performance than traditional materials. Zhang et al 17 and Ma et al 18 developed new damping materials, such as metal rubber and shape memory alloys, which are now widely used in the field of launch dynamics.…”

“…Researchers have proposed a range of strategies to decrease the effect of the shock response based on these previous investigations. Reducing the energetic material mass is acknowledged as one of the most effective ways, but this solution leads to performance degradation of the gas generator 12,13 . Some investigations suggested using the method of absorbing shock by utilizing honeycomb materials with high shock resistance, 14,15 and other investigations 16 confirmed that honeycomb composites had superior buffer performance than traditional materials.…”

Numerical Study of Separation Characteristics of Piston‐Type Explosive Bolt

“…An explosive bolt is a simple, highly reliable, and efficient pyrotechnic release device widely used in the aerospace industry [1,2]. Various types of explosive bolts have been designed, including "ridge-cut" [3,4], fragmenting-type [5], piston-type [6,7], shear-type [8,9], and shear pin-type explosive bolts [10], among others. e action of explosive bolts inevitably induces high-frequency and highamplitude transient shock, known as pyroshock, which rarely causes structure failure.…”