Accession Number : ADA117011

Title :   The Mechanical Behavior of Gun Propellant Grains in Interior Ballistics.

Descriptive Note : Technical rept.,

Corporate Author : ARMY ARMAMENT RESEARCH AND DEVELOPMENT COMMAND DOVER NJ LARGE CALIBER WEAPON SYSTEMS LAB

Personal Author(s) : Nicolaides,S ; Wiegand,D A ; Pinto,J

PDF Url : ADA117011

Report Date : Jun 1982

Pagination or Media Count : 25

Abstract : The interior ballistics problem associated with the erratic and adnormal burning of gun propellant grains is addressed interms of the mechanical behavior of the propellant. Compressive mechanical properties, grain failure, and burning performance of two triple base propellants tested as a strain rate of 1000% per second and at ambient temperatures ranging from 20 C to -60 C are presented. As the test temperature is lowered the propellants undergo a change from ductile to brittle mechanical stress-strain behavior; the associated grain failure proceeds with a decrease in the amount of plastic nonfragmenting type deformation and an increase in the extend of fragmenting type fracture. The extent of fracture or breakup changes the prescribed surface area of the characteristics of the propellant design. Closed bomb tests with normal and with mechanically-failed grains show increases in relative quickness sufficient to produce unsafe gun firing conditions. Changes in the mechanical properties of nitroguanidine propellants observed over a period of 1 year suggest that aging can cause propellant embrittlement.

Descriptors :   *Gun propellants, *Propellant grains, *Interior ballistics, *Mechanical properties, Compressive properties, Ductile brittle transition, Burning rate, Strain rate, Nitroguanidine, Plastic deformation, Fracture(Mechanics), Glass, Transition temperature, Closed bomb tests, Fragmentation, Stress strain relations, Aging(Materials), Mechanical properties, Cracks, Ductility, Strain rate

Subject Categories : Ammunition and Explosives
      Ballistics

Distribution Statement : APPROVED FOR PUBLIC RELEASE