Fracture toughness determination of SiC/SiC fabric composites

Conference · Fri Dec 01 04:00:00 EST 1995

OSTI ID:135792

Kobayashi, H; Todoroki, A; Nakamura, H ^[1]

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1. Toyko Institute of Technology (Japan)

It is well known that ceramic matrix composites (CMC) have improved fracture toughness. Under existence of a sharp defect, however, CMC show nonlinear and nonelastic behavior and yield many microcracks around a main crack tip. A conventional fracture toughness measuring technique developed for many kinds of metallic materials, therefore, cannot be directly applied to the toughness evaluation of CMC. Toward an establishment of a simple approach applicable to structural damage tolerant designs, SiC/SiC fabricated composites were used to evaluate the fracture toughness in this study. Two types of specimens were tested and an evaluation method of the fracture toughness were discussed experimentally. It is shown that the fracture resistance curve and the fracture toughness as a material property can be evaluated in terms of a stress intensity factor using an equivalent crack length calculated from a compliance regarding the origin of a load-deflection curve.

• OSTI ID: 135792
• Report Number(s): CONF-9508127--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRACK PROPAGATION
FRACTURE PROPERTIES
MECHANICAL PROPERTIES
MICROSTRUCTURE
SILICON CARBIDES
STRESS INTENSITY FACTORS
TEMPERATURE DEPENDENCE