Analysis of inclusion stress response in materials surrounding a torpedo shaped gage package

Technical Report · Tue Nov 01 04:00:00 EST 1988

OSTI ID:6567560

Stout, R B; Larson, D B; Thigpen, L

A displacement-stress analysis of a torpedo-shaped gage package is developed. This analysis is necessary in order to infer compressive stress-strain history data from the response of the gage when it is embedded in a material that surrounds an underground nuclear explosion. A torpedo-shaped gage package consists of a copper shell surrounding a cylinder of PMMA with embedded piezoresistive foils. Recent experimental and analytical results are reviewed which showed that the resistance response from foils embedded in PMMA can be inverted to obtain a set of stress-strain histories in the PMMA. In axial-symmetrical loaded geometries, this set of stress-strain histories is sufficient to completely describe the elastic displacement and stress response of the PMMA cylinder. By matching displacement and traction boundary conditions at the PMMA-copper interface the elastic response of the copper can also be described. The next analysis step is to relate the displacement-stress response at the exterior surface of the copper shell to the stress response in the surrounding material. Two different cases are considered: one case is called quasi-plane strain to approximate an axially weak gage package relative to the strength of the surrounding material, and the second case is called quasi-plane stress to approximate an axially strong gage package relative to the strength of the surrounding material. Results show that compressive stress histories inferred in the surrounding material are greater than compressive stress histories measured in the PMMA for a ''weak'' gage package placed in a ''strong'' surrounding material. And for the other situation of a ''strong'' gage package placed in a ''weak'' surrounding material are less than the compressive stress histories measured in the PMMA. 12 refs., 5 figs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6567560
• Report Number(s): UCID-21553; ON: DE89002822
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450200 -- Military Technology
Weaponry
& National Defense-- Nuclear Explosions & Explosives
COPPER
CYLINDERS
DEFORMATION
ELASTICITY
ELECTRICITY
ELEMENTS
EQUATIONS
ESTERS
EXPLOSIONS
FOILS
MEASURING INSTRUMENTS
MECHANICAL PROPERTIES
METALS
NUCLEAR EXPLOSIONS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PIEZOELECTRICITY
PMMA
POLYACRYLATES
POLYMERS
POLYVINYLS
STRAIN GAGES
STRAINS
STRESS ANALYSIS
TENSILE PROPERTIES
TRANSITION ELEMENTS