Mechanical characterization of IM7/8551-7 carbon/epoxy under biaxial stress: (Final report)

Technical Report · Fri Nov 13 00:00:00 EST 1987

OSTI ID:5613415

Colvin, Jr, G E; Swanson, S R

This is the final report on an investigation to evaluate the mechanical response of Hercules IM7/8551-7 carbon/epoxy, which is a high strength, high elongation fiber and a high toughness resin system used in a prepreg form. The material characterization involved testing both laminate and lamina forms under a wide range of biaxial stress states. Tubular specimens were employed that have been designed to eliminate undesirable end effects, permitting uniform stress states to be achieved. Quasi-isotropic (90/+-45/0)/sub ns/laminates and (90)/sub 16T/ lamina specimens were loaded under combinations of internal pressure, axial load, and torsion. Both stiffness and strength data were obtained under these multiaxial stress conditions. The measured laminate stiffnesses correlated well using classical laminated plate theory, and that laminate failure occurred in the two separate modes of matrix cracking and fiber failure. Like the previously examined carbon/epoxy systems, laminate failure could be predicted by using a fiber failure criterion to identify the critical plies and critical load levels. It was found that either maximum fiber stress or fiber direction strain could be used as a failure criterion on a ply level. 16 refs., 10 figs., 3 tabs.

• Research Organization: Utah Univ., Salt Lake City (USA). Dept. of Mechanical Engineering
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5613415
• Report Number(s): UCRL-15977; ON: DE88004058
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
MECHANICAL PROPERTIES
CARBON COMPOUNDS
COMPRESSIBILITY
CRACKS
EPOXIDES
FAILURES
FIBERS
LAYERS
MATERIALS TESTING
PROGRESS REPORT
RESINS
SHEAR
STRESSES
TUBES
DOCUMENT TYPES
MATERIALS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
POLYMERS
TESTING
360603* - Materials- Properties