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

Technical Report · Tue Jun 03 04:00:00 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

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