Accession Number : ADP004344

Title :   Antiplane Cracks in Solid Propellants,


Personal Author(s) : Ju,F. D. ; Jacoby,J. J.

Report Date : JUN 1984

Pagination or Media Count : 9

Abstract : This work investigates a mechanism for solid propellant hazard. That mechanism is a consequence of friction from a running antiplane crack propagating in its own plane. When a continuum that contains a crack is subjected to an applied load at some oblique angle to the face of the crack, then the load may be resolved into a shear stress and a normal stress. The normal stress causes friction at the crack surface that resists further growth of the crack while the shear stress provides the driving force for crack growth. It follows that for given crack characteristics and given load, the kinematics of the crack depend on the crack orientation with respect to the load. Continuous displacement in the antiplane direction will occur provided the shear stress is sufficient to cause the crack to grow. Under the conditions of continuous crack growth the friction energy will depend upon the normal pressure. There may exist combinations of applied load and crack orientations, that will lead to a deflagration to detonation transition of the propellant. Of fundamental importance is a stability criterion for a single crack, which is the subject of this paper. By making a number of simplifying assumptions it is possible to derive this stability criterion analytically. This result will subsequently be used to verify computer simulations before investigating more realistic material properties. (Author)

Descriptors :   *Solid propellants, *Crack propagation, *Hazards, Cracks, Friction, Heating, Loads(Forces), Shear properties, Stresses, Kinematics, Displacement, Stability, Standards, Mathematical analysis, Symposia

Distribution Statement : APPROVED FOR PUBLIC RELEASE