The thermal response of the ignition and combustion of high-energy material projectiles under the influence of heat

Abstract

The thermal response of energetic materials involves processes of thermochemical mechanical coupling, which can lead to thermal damage in such materials both before and after ignition, thereby increasing ignition sensitivity and the level of danger. Many studies to date have either neglected or oversimplified the effects of thermal coupling, leading to significant discrepancies between simulated and experimental outcomes. This paper aims to examine the complex processes of ammunition ignition, combustion, and detonation. Employing finite element simulations in conjunction with Arrhenius dynamics and the ignition growth model theory under thermodynamic coupling analysis, it simulates the entire process from the thermal expansion of B explosive prior to ignition, through to combustion and detonation. It establishes the relationship between the damage and fracture state of the shell and the thermal response of the energetic material at varying heating rates. Findings indicate that the severity of the thermal response is determined by the balance between pressure accumulation and the loss of confinement leading to pressure release. Specifically, at heating rates below 0.25 K/min, the shell fractures before combustion of the energetic material; whereas, at rates exceeding 0.375 K/min, the shell fractures after combustion, significantly increasing the risk. The simulation outcomes of this study show strong correlation with experimental results reported in the literature, offering a valuable reference for simulating the ignition and combustion responses of ammunition with similar structural characteristics.