Research on NEPE Propellant at High Strain Rates

Abstract In order to study the mechanical properties of Nitrate Ester Plasticized Polyether (NEPE) propellant at high strain rates, the impact tests of NEPE propellant were carried out by the split Hopkinson bar, and the stress-strain curves of NEPE propellant under different strain rates ( 1500s−1-4500s−1 ) were obtained. The test results show that NEPE propellant has obvious nonlinear elasticity and strain rate sensitivity. The microstructure of NEPE propellant was observed by scanning electron microscope, and the fracture mechanism of NEPE propellant under high strain rate was obtained by analyzing the microstructure of propellant. In this paper, a nonlinear visco-hyperelastic constitutive model is adopted, in which Rivlin model and the viscoelastic model are used to describe the mechanical properties of materials. The constitutive parameters of the material were obtained by fitting the test data, and it was proved that the model could well describe the mechanical properties of NEPE propellant at high strain rates by comparing the test curve under different strain rates.