Effect of Initial Crack Position on Low‐intensity Impact Ignition Performance of Solid Propellant

ABSTRACT The micro‐crack defects produced in the process of storage and use of solid propellants have an important influence on the safety of solid propellants. In this study, the low‐intensity impact ignition performance of crack‐containing hydroxyl‐terminated polybutadiene (HTPB) propellant was studied. According to the typical HTPB solid propellant formula, the mesoscopic models of defect‐free HTPB propellant and HTPB propellant with different crack positions were established. The Cohesive element was inserted globally. The friction heat generation inside the material and microcracks, the deformation heat generation of ammonium perchlorate (AP) particles and the exothermic reaction of AP particles were considered. The drop hammer impact process of HTPB propellant with crack defects was simulated, and the influence of initial crack position on the low‐intensity impact ignition response time of solid propellant was studied. The results show that the ignition response time of the defect‐free HTPB propellant is 0.38 ms, and the ignition temperature is 621 K; the ignition time of HTPB propellant with crack defects in AP particles, interface, and matrix is 0.33, 0.34, and 0.36 ms, respectively. The ignition temperature is 578, 584, and 597 K.