Low‐Temperature Mesoscopic Mechanical Damage of AP/Al/HTPB Composite Propellants

This is the authors' abstract. We don't add key points for this paper.

To investigate the mechanical damage of solid propellants under low‐temperature conditions, an equivalent modeling approach was employed to establish a mesoscopic particle–embedded model of the hydroxyl‐terminated polybutadiene (HTPB) propellant. Uniaxial tensile numerical simulations were conducted on the propellant under varying strain rates and temperatures to examine the debonding damage and binder matrix brittle fracture phenomena at low temperatures. Additionally, a comparative analysis was performed on the matrix damage of propellants containing initial voids under low‐temperature conditions. The results indicate that the debonding damage stress of the propellant increases with decreasing temperature and increasing strain rate. Under low‐temperature and high‐strain‐rate conditions, two distinct damage modes were observed: solid particle debonding and binder matrix fracture, accompanied by a pronounced double‐peak phenomenon in the stress–strain curve. For propellants containing voids, the stress required to initiate particle debonding and binder matrix fracture was found to decrease, whereas the extent of damage became more severe. Through numerical simulations of solid propellants under low‐temperature conditions, this paper elucidates the processes of particle debonding and binder matrix fracture, as well as the stress–strain relationship during tensile loading, from a mesoscopic perspective. These findings contribute to advancing research in micromechanical numerical simulations of solid propellants.