Micromechanics of ambient temperature cyclic fatigue loading in a composite of CAS glass ceramic reinforced with Nicalon fibers

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Journal of Composites Technology and Research; (United States)

OSTI ID:7180742

Rousseau, C Q; Davidson, D L; Campbell, J B ^[1]

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1. Bell Helicopter/Textron Inc., Ft. Worth, TX (United States)

The behavior of a Nicalon fiber reinforced glass ceramic composite cyclicly loaded has been evaluated at ambient temperature using high-resolution micromechanical test methods. On this basis, the events leading to fracture have been found to be similar to those accompanying fracture in unidirectional tension tests. Matrix strains were determined locally at the point of matrix fracture. Crack opening displacements (CODs) were measured as a function of loading cycles, and fiber strains were determined, in some cases. It is concluded that debonding of fibers begins at the point of matrix cracking and rapidly increases. Most of the cyclic lifetime of the material is spent with fibers debonded over large distances (fractions of a millimeter); these fibers are pulled out of the matrix on each loading cycle. Final debond length, as determined by fractography, is a function of the number of cycles to fracture, and of the applied stress level. 23 refs.

• OSTI ID: 7180742
• Journal Information: Journal of Composites Technology and Research; (United States), Journal Name: Journal of Composites Technology and Research; (United States) Vol. 16:2; ISSN JCTRER; ISSN 0885-6804
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602 -- Other Materials-- Structure & Phase Studies
360603* -- Materials-- Properties
CARBIDES
CARBON COMPOUNDS
CERAMICS
COMPOSITE MATERIALS
FATIGUE
FRACTOGRAPHY
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
SILICON CARBIDES
SILICON COMPOUNDS
THERMAL FATIGUE