HTPE/AP/Al/RDX推进剂的准静态拉伸力学性能

To study the quasi-static stretch mechanical properties of HTPE/AP/Al/RDX propellants over a wide temperature range, the stress-strain curves of HTPE/AP/Al/RDX propellants were obtained by uniaxial tensile tests over the temperature range of -50 to 70℃ and at five different strain rates. The damage failure forms of the propellants were analyzed by means of the sectional morphology method. The effect of temperature and tensile rate on the mechanical properties of the propellant was analyzed, and the related mechanical property master curves were fitted. The results show that the maximum tensile strength of HTPE/AP/Al/RDX propellant decreases from 5.44 MPa at -50℃ to 0.75MPa at 70℃. The elongation at fracture decreases after increasing, reaching a maximum of 75.9% at room temperature and a minimum of 25.9% at -50℃. The maximum tensile strength increases with increasing the strain rate, e.g. from 1.99MPa to 5.44MPa at -50℃, while the elongation changes complexly. The fracture of HTPE/AP/Al/RDX propellants undergoes a brittle-tough transition, with damage to the propellants at ambient and high temperatures being mainly dehumidification. The damage at low temperatures is dominated by tearing of the binder matrix and grain-through fracture of the filler, and grain-through fracture of the filler is more significant with increasing the strain rate. The maximum tensile strength of HTPE propellants at different strain rates over temperature range from -50℃ to 70℃ can be predicted by means of the mechanical properties master curve, assisting in the analysis of the structural integrity of the charge and laying the foundation for the practical application of HTPE propellants.