Accession Number:

ADA017632

Title:

Static and Fatigue Damage Characterization in Composite Materials.

Descriptive Note:

Final rept. Jun 74-Jul 75,

Corporate Author:

UNITED TECHNOLOGIES CORP STRATFORD CONN SIKORSKY AIRCRAFT DIV

Personal Author(s):

• Nevadunsky,Joseph J.
• Matusovich,C. J.
• Lucas,John J.

Report Date:

1975-08-01

Pagination or Media Count:

58.0

Abstract:

The purpose of the investigation was to characterize two composite laminates. This was accomplished by identifying static and fatigue modes present within the laminates by fractographic and non-destructive tests methods and relating them to stiffness loss. Torsional and axial modulus measurements were employed to quantitatively characterize the materials. Microscopic examinations, both visual and SEM were used to destructively evaluate the failure mechanisms present at various stages of static and fatigue damage. Observations of heat generation, ultrasonics, holographic interferometry, and speckle interferometry were conducted to qualitatively characterize both the failure mechanisms and stiffness loss they cause. This approach is aimed at completely characterizing composite laminates for their structural integrity throughout their static and fatigue lives.

Descriptors:

• *COMPOSITE MATERIALS
• *LAMINATES
• STATIC TESTS
• FATIGUE TESTS(MECHANICS)
• NONDESTRUCTIVE TESTING
• DAMAGE
• FIBER REINFORCED COMPOSITES
• GLASS REINFORCED PLASTICS
• FIBERGLASS
• EPOXY RESINS
• CARBON FIBERS
• FATIGUE(MECHANICS)
• FRACTURE(MECHANICS)
• STRUCTURAL PROPERTIES
• HELICOPTERS
• AIRFRAMES

Subject Categories:

• Helicopters
• Laminates and Composite Materials

Distribution Statement:

APPROVED FOR PUBLIC RELEASE