CHARACTERIZATION OF IMPACT-INDUCED VIOLENT REACTION BEHAVIOR IN SOLIDROCKET MOTORS USING A PLANAR MOTOR TEST MODEL

A planar model of a solid rocket motor with a central bore has been de veloped that allows visual observation of impact-induced violent react ion processes (e.g., nondetonative explosions and delayed detonations) . Studies have been conducted, using this model, to characterize the r esponse of lull-scale motors to projectile impact. A comparison of exp losive burn reaction data from planar model and full-scale tests shows a number of similarities. In particular, displays of burning, fragmen ted propellant ejecta are qualitatively the same. In planar motor test s, these displays result from two reactions, a brief, intense one with in the bore and a longer duration, less intense one within the web. Th ese tests also show an apparent inverse relation between the two react ions, for some propellants, arising as a result of bore width changes or mechanical properly differences. This paper summarizes the results of a number of studies conducted to characterize the two types of reac tions and define the relationship between them. These studies show tha t the two are independent events and that the inverse relation, when i t involves bore width changes, is most likely the result of depressuri zation-related phenomena whereas, when it involves mechanical property differences, may be the result of penetration heating differences.