On the specimen dependence of unidirectional boron/aluminum fracture toughness

Journal Article · Tue Jan 01 04:00:00 EST 1980 · Journal of Composite Materials Supplement; (United States)

DOI:https://doi.org/10.1177/002199838001400109· OSTI ID:5691475

Reedy, Jr, E D

Fracture toughness, as commonly defined for unidirectional boron/aluminum, was measured with center-notched, compact tension, and various sized three-point bend specimens. All coupons were cut from the same plate of material. The values of fracture toughness determined were found to be specimen dependent, thus indicating that fracture toughness is not a material property for the size and type of specimens tested. The failure mode was also found to be specimen dependent. Crack growth colinear with the notch occurred in the center-notched and three-point bend specimens, while the crack initiated and propagated perpendicular to the notch tip in compact tension specimens. The failure of linear elastic fracture mechanics to define a material property for these specimens was attributed to extensive matrix yielding in regions remote from the notch tip. The existence of widespread matrix yielding was confirmed with a strain gaged, center-notched tensile specimen.

• Research Organization: Sandia Laboratories, Albuquerque, N. Mex.
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5691475
• Journal Information: Journal of Composite Materials Supplement; (United States), Journal Name: Journal of Composite Materials Supplement; (United States) Vol. 14
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360303* -- Composite Materials-- Mechanical Properties-- (-1987)
ALUMINIUM
BENDING
BORON
COMPOSITE MATERIALS
CRACK PROPAGATION
ELEMENTS
FAILURE MODE ANALYSIS
FAILURES
FATIGUE
FRACTURES
GEOMETRY
MATERIALS
MATERIALS TESTING
MATHEMATICS
MECHANICAL PROPERTIES
METALS
REINFORCED MATERIALS
SEMIMETALS
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
TESTING