Evaluation of filament-wound Kevlar-49/epoxy fatigue properties. Final report

Technical Report · Tue Jun 03 00:00:00 EDT 1980

OSTI ID:5220686

This study was conducted by AiResearch Manufacturing of California for LLL to investigate the long-term properties of Kevlar-49/epoxy composite in a fatigue and elevated temperature environment to provide additional information on the material properties of Kevlar-49/epoxy for use in the design of composite flywheel energy storage units. Testing showed that Kevlar-49 has the unusual property of increasing tensile modulus of elasticity under fatigue loading conditions. The change in modulus was shown to be a function of temperature, induced stress level, and number of fatigue cycles. The average modulus before cycling was 13.28 x 10/sup 6/ psi at ambient temperature versus 11.96 x 10/sup 6/ psi at 150/sup 0/F. Creep or residual strain after 100,000 cycles was 4.1 x 10/sup -4/ in/in (ambient) and 11.7 x 10/sup -4/ in/in (150/sup 0/F) at 140 ksi maximum stress level. At 190 ksi temperature did not show any effects on creep, which was measured to be approximately 28 x 10/sup -4/ in/in. The ultimate strength of 150/sup 0/F rings was 249,000 psi compared to 262,000 psi for ambient temperature.

• Research Organization: AiResearch Mfg. Co., Torrance, CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5220686
• Report Number(s): UCRL-15264
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
33 ADVANCED PROPULSION SYSTEMS
ARAMIDS
TENSILE PROPERTIES
EPOXIDES
CREEP
ELASTICITY
FATIGUE
FLYWHEEL ENERGY STORAGE
RESIDUAL STRESSES
THERMAL STRESSES
ENERGY STORAGE
MECHANICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
STORAGE
STRESSES
360303* - Composite Materials- Mechanical Properties- (-1987)
330500 - Advanced Propulsion Systems- Flywheel Propulsion