Fatigue behavior of ceramic matrix composites at elevated temperatures under cyclic loading

To achieve satisfactory levels of strength, fracture toughness, and reliability for man-rated systems such as jet engines, fiber reinforced ceramic matrix composites are needed. An elevated temperature axial testing system is developed to investigate and characterize fatigue behavior of Nicalon fiber reinforced enhanced silicon carbide matrix. composites at 1800 of under fully reversed cyclic loading. Notch effect on quasi-static tensile response is also considered. Quasi-static and fatigue damage mechanisms and failure modes are examined using various specimen geometries, load levels, fatigue ratios, and laminates stacking sequences by employing a number of NDE techniques. Issues such as damage tolerance and durability are addressed by conducting interrupted fatigue tests at various stages of life for different load levels. Results are compared to the predictions of remaining strength and life, obtained using a performance simulation code. Initial results indicate existence of a threshold stress value which limits the use of the material system.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Engineering Mechanics

Department dc:contributor.department

Engineering Mechanics

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1996

Author dc:creator

• Elahi, Mehran

Chair dc:contributor.committeechair

• Reifsnider, Kenneth L.

Committee members dc:contributor.committeemember

• Duke, John C. Jr.
• Mook, Dean T.
• Kriz, Ronald D.
• Johnson, Eric R.

• life prediction
• ceramic matrix composites
• Fatigue
• elevated temperature
• strength prediction
• life
• remaining strength

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-06062008-154429

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/38074