Study on dynamic deformation-damage-ignition mechanism of GAP/RDX/TEGDN propellant

ABSTRACTInvestigations on high-energy and low-vulnerability propellants can provide a better understanding for improving the operational effectiveness and survivability of strategic and tactical missiles. In the present study, the dynamic compressive mechanical properties and damage-ignition response mechanism of the GAP/RDX/TEGDN (GRT) propellant under high strain rates have been studied using a split Hopkinson pressure bar apparatus and a high-performance high-speed camera. The experimental results suggested that the mechanical properties of the GRT propellant, in terms of yield stress, initial compressive modulus, and ultimate stress, were greatly affected by the loaded strain rate. The true stress-strain curves exhibited an initial linear elasticity region followed by yielding a subsequent strain hardening and strain softening region stage. It has been found that the yield stress and ultimate stress increased with the strain rates. Moreover, at higher strain rates, the impulse increases significantly, leading to earlier and more intense ignition. The critical strain rate and the critical impulse of the GRT propellant are 5000 s−1 and 13.28 N · s, respectively. A judgment basis for GRT propellant ignition is established. Finally, according to the high-speed images and the posttest SEM images, it has been concluded that the dominant ignition mechanism of GRT propellant is flow at the macroscopic level and internal frictional heating at the mesoscopic level.KEYWORDS: Compressive mechanical propertiescritical impulseGRT propellantignition mechanisminternal frictional heating AcknowledgmentsThe authors would like to thank Joint key programs of National Natural Science Foundation of China (U22B20131) and State Key Laboratory of Explosion Science and Technology (QNKT23-10) for supporting this project.Disclosure statementNo potential conflict of interest was reported by the author(s).Author ContributionsLiying Dong has completed the design of experimental methods, practical investigation and research, analysis of experimental data, visualization of experimental results, and writing the first draft of the paper. Yanqing Wu is the corresponding author of this article. The author is involved in research concept generation, research funding acquisition, research resource collection, experimental design verification and verification, research topic supervision and guidance, and paper review. Kun Yang helped perform the analysis with constructive discussions. Junwu Zhu helped with the experiment. Xiao Hou helped with the paper review.Additional informationFundingThis work was supported by the National Natural Science Foundation of China [U22B20131]; State Key Laboratory of Explosion Science and Technology [QNKT23-10].