Effect of Confinement on the Mechanical Response of Composite Plastic Bonded Explosives
Abstract
The mechanical properties of composite explosives are being studied as a function of mechanical confinement and three techniques for confinement were used. These are: (a) a constant confining pressure obtained by oil immersion, (b) radial confinement of a cylindrical sample by a thick walled steel cylinder that surrounds the sample (negligible radial strain), and (c) radial confinement of thin wafers by the platen-sample friction. while many energetic materials fail by crack growth when unconfined (significant surface area free of stress), with all of these forms of confinement, they appear to fail by yield and plastic flow. For crystalline explosives (e.g., TNT and Composition B), the yield strength and the modulus are independent of confining pressure so that useful results can be easily obtained by use of the steel cylinder technique. However, for materials containing polymer binders, such as plastic bonded explosives, a constant confining pressure is used because these properties are found to significantly increase with this pressure. These results indicate the very significant role of the polymer binders in determining the mechanical properties of these energetic materials.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2000
- Accession Number
- ADA376411
Entities
People
- Donald A. Wiegand
Organizations
- United States Army Armament Research, Development and Engineering Center