Impact-Generated Surface Area in Gun Propellants
Abstract
The fracture damage suffered by gun propellant grains during the early part of the ballistic cycle greatly affects the evolution of chamber pressure and gun performance. Significant fracture can lead to generation of pressure waves and catastrophic gun failure. It would be greatly advantageous if ballistic codes could provide predictions for the effect of grain fractures. To do this, the amount of fracture damage occurring due to the impact stresses must be know. Much work, has been done to characterize the mechanical response of the propellant so the conditions under which embrittlement occurs are better understood. Fracture damage has been evaluated for impacted grains under a wide range of impact conditions and deviations from normal pressurization have resulted in calculated fracture generated surface area. However, these results are based on closed bomb-pressure-time data. Calculations needed to generate the fracture surface area are laborious and are only reliable after a significant portion of the propellant has been consumed. In order to provide ballistic codes with the information needed to predict the effects of grain fracture, a new and easily obtained relationship is needed. This report outlines efforts to develop such a relationship, and the progress being made to incorporate fracture damage into ballistic codes. Keywords: Interior ballistics computer programming; Mechanical properties; Impact tests.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1988
- Accession Number
- ADA200468
Entities
People
- Robert J. Lieb
Organizations
- Ballistic Research Laboratory