Effect of Microstructure on Micro-Mechanical Properties of Composite Solid Propellant

This study was aimed at determining the effect of microstructure on the macro-mechanical behavior of a composite solid propellant. The microstructure model of a composite solid propellant was generated using molecular dynamics algorithm. The correlation of how microstructural mechanical properties and the effect of initial interface defects in propellant act on the macro-mechanics were studied. Results of this study showed that the mechanical properties of propellant rely heavily on its mesoscopic structure. The grain filling volume fraction mainly influences the propellant initial modulus, the higher the volume fraction, the higher initial modulus. Additionally, it was found that the ratio of particles influences the tensile strength and breaking elongation rate of the propellant. The big particles could also improve the initial modulus of a propellant, but decrease its tensile strength and breaking elongation rate. Furthermore, the initial defects lowered the uniaxial tensile modulus, tensile strength, and the relaxation modulus of propellant, but did not affect the relaxation behavior of the propellant.

Solid Propellant Formulations: A Review of Recent Progress and Utilized Components

The latest developments in solid propellants and their components are summarized. Particular attention is given to emerging energetic binders and novel, ‘green’ oxidizing agents and their use in propellant formulations. A brief overview of the latest reports on fuel additives is included. Finally, a summary of the state of the art and challenges in its development are speculated on.

Crack Propagation Analysis of Damaged Solid Propellant under Impact Overload

The ammunition safety problem is particularly prominent when the storage and transportation launch box is airdropped and landed. A safety evaluation method of rocket air drop based on propellant damage evaluation is proposed. Based on the theory of fracture mechanics and the evaluation method of structural integrity of rocket engine, established a local finite element model of rocket engine with initial damage, the crack propagation analysis is carried out by using the propagation finite element method (XFEM). The results show that when the landing impact overload is 30g (25ms) that the airdrop equipment should be able to withstand, the modified double base propellant has produced the phenomenon of crack instability propagation. When the initial crack direction and load direction are 120 °, the propagation is the most serious and there are safety problems; when the solid propellant is airdropped, it is necessary to increase the buffer to reduce the overload.