Accelerated ageing of composite solid propellants under cyclic temperature variations
Hamza Naseem, H. Murthy, P. A. Ramakrishna
Abstract
A novel cyclic-thermal method is proposed for accelerated thermo-chemical ageing of composite solid propellants including the diurnal and seasonal variations in temperature, the main environmental factor. For accelerated ageing corresponding to natural ages of up to 5 years, natural variations during 24 hours were reduced to 90 to 214 minutes by increasing the mean temperature using Arrhenius relationship and heat diffusion analysis. Degradation, in terms of physical and tensile properties, indicates that the ambient temperature variations (temperature rate) have a significant effect on propellant ageing. Ageing-related stiffening, embrittlement, and reduction in dewetting strain indicate onset of particle-binder interface failure.