Experimental studies of propellant specimen and motor behavior during failure provide insight into the probable mechanisms of failure in a composite propellant system. At low rates and high temperatures, failure results from at least two successive processes: first, a dewetting or breaking of the binder to oxidizer bonds, and second, a tearing in the binder structure initiated at points of stress concentration such as regions of binder-oxidizer dewetting. Stress-strain analysis of a motor shows the potential failure points, and a failure analysis indicates the required mechanical properties to withstand failure. Laboratory testing has given a method of classifying propellant behavior, an estimate of material failure variability, and a method of correlating the uniaxial with biaxial tensile properties and with rate and temperature of test. Uniaxial tensile properties are obtained more conveniently by laboratory measurements, but biaxial properties appear to be related more directly to inner bore grain cracking. Good correlations were demonstrated between motor failures in thermal cycling and the failure properties of the propellant from laboratory tests.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.