Strength Criterion of HTPB Composite Solid Propellant under Tension‐Shear Loading at Low Temperature

• Published in: Propellants, explosives, pyrotechnics explosives, pyrotechnics, 2022-05, Vol.47 (5), p.n/a
• Main Authors: Wang, Jia‐xiang, Qiang, Hong‐fu, Wang, Zhe‐jun
• Format: Article
• Language: English
• Subjects: Bearing capacity; Composite propellants; Criteria; HTPB Propellant; HTPB propellants; Low temperature; Mechanical properties; Polybutadiene; Propellant tests; Shear rate; Shear tests; Solid propellants; Strain analysis; Strain rate; Strength criterion; Temperature; Tension-shear loading; Ultimate loads
• ISSN: 0721-3115; 1521-4087
• DOI: 10.1002/prep.202100267

The strength limits of composite solid propellants are different at different temperatures and loading states. To study the ultimate bearing capacity of Hydroxyl‐terminated polybutadiene (HTPB) propellant, the tensile‐shear loading fixture and propellant specimens were designed, and the tensile‐shear tests of HTPB propellant at different temperatures (223–298 K) and strain rates (0.01–1.00 s−1) were carried out. The variation of ultimate load of HTPB propellant with loading conditions was analysed. Based on the twin shear unified strength theory, the strength criterion of HTPB propellant under low temperature tension‐shear load was established, and the variation of mechanical parameters and stress limit surface with temperature and strain rate were analysed. The results show that the twin shear unified strength theory can be well applied to the strength analysis of propellants. The ultimate bearing capacity of HTPB propellant is the smallest near the loading angle of 45°. The shape of strength limit surface is an equilateral semi‐infinite hexahedron. With the decrease of temperature and the increase of shear rate, the strength limit surface of HTPB propellant expands outward.