Dynamic fracture of simulated solid propellant

Dynamic loads generated in a shock tube were applied to the inner bore of annular specimens of a simulated solid propellant. The load pulse-shape was approximately triangular, with essentially zero rise-time, a duration of about 0.25 msec, and a variable intensity. At each particular pressure level the loading was repeated on a specimen until fracture of the specimen occurred. In this fashion it was possible to construct a low-cycle dynamic fatigue curve for the material used. It appears that a simple energy criterion describes the fracture behavior reasonably well.