Thermal Safety of a Gun‐Launched Missile's Solid Rocket Motor Under Conditions of High Environm. Temp. and Overloaded Forces

Abstract

To verify a hypothetical failure cause of a gunlaunched missile's solid rocket motor (SRM) under conditions of high environmental temperatures and overloaded forces of up to 6000~12000 g, experiments and simulations were conducted and a new criterion variable was proposed. Uniaxial compression tests of the composite modified double base (CMDB) propellant used in the gun-launched missile were carried out at low and intermediate strain rates at 50 8C to characterize the CMDB propellant's dynamic properties. The Schapery nonlinear viscoelastic constitutive model was employed and applied in finite element analy-ses. Contact and an oscillating frictional direction between the grain and the case were observed when the overload curve oscillated with time. Three key variables of the process were researched: the contact pressure, the relative velocity, and the total contact time. Based on these, a new criterion variable q is proposed for judgements regarding the SRM's thermal safety. By comparing the results with those from friction sensitivity tests, it was discovered that the grain had a possibility of self-ignition that cannot be ignored. Meanwhile, the gap width between the case and the grain was determined to be a key influencing factor.Keywords: gun-launched missile · CMDB propellant · high oscillational overload · high temperature · explosion [a] W.

The Auto‐Ignition Behaviors and Thermal Safety of the Composite Modified Double Base Propellants under Rapid Heating

“…pep.wiley-vch.de high temperature and overloaded forces was studied by uniaxial compression tests [11]. Results show that auto-ignition may happen during friction sensitivity tests, and cannot be ignored.…”

“…Many researchers have focused on the studies of the explosive safety and combustion for CMDB propellants [2,[8][9][10][11]. Denisyuk et al added high explosives (RDX or HMX) into double-base propellants to improve their energy characteristics.…”

“…It was indicated that the combustion mechanisms of CMDB are mainly involved with oxidation mechanisms of NO 2 , formaldehyde (CH 2 O), and hydrogen cyanide (HCN). In addition, the thermal safety of CMDB containing HMX under high temperature and overloaded forces was studied by uniaxial compression tests [11]. Results show that auto‐ignition may happen during friction sensitivity tests, and cannot be ignored.…”

Analysis of the mechanical response of solid rocket engine propellant under acceleration shock

“…These damages, after continuous accumulation, can lead to irreversible macro-level destruction [5][6][7] . If the propellant charge deforms or even breaks, it will alter the predetermined thrust plan, cause severe degradation in the performance of the solid rocket engine, and lead to engine burn-through or even disintegration and explosion during operation [8] .…”

Investigation of the Effect of Axial Gap on the Mechanical Response of a Cartridge-Loaded CMDB Propellant Grain under Vibration Loads

“…In cartridge-loaded solid rocket motors, the propellant grains are manufactured separately from the case and then loaded into or assembled into the case. The propellant grain is normally fixed by the forward and backwards support inside motor cases [7][8][9][10][11]. The cartridge-loaded SRM has the advantage of low cost and ease of inspection and is commonly used in small missiles and a few medium-sized motors [12][13][14].…”