Fatigue response of notched graphite--epoxy laminates

Changes in the stiffness and strength of notched quasi-isotropic graphite-epoxy laminates were recorded and related to the fatigue damage. Two different laminates [0,90,+45,-45]s (type A) and [ +45, 90, -45, 0] s (type B) were considered and the effects of stacking sequence were compared. Nondestructive testing techniques such as X-radiography, moire technique, acoustic emission, deply technique, and stiffness change were performed to observe damage development. Static properties and damage initiation were related to an approximate stress analysis. Results show that the mechanical response and the fatigue damage depend strongly on the stacking sequence of laminates. In general, residual strength increased remarkably for both laminates due to stress redistributions while the continuous stiffness change curve is typical for each laminate and reflects damage characteristics. Buckling effects as well as matrix cracking and delaminations contribute to stiffness changes.

Name thesis:degree_name

M.S.

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Engineering Mechanics

Department dc:contributor.department

Engineering Mechanics

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1983

Author dc:creator

• Kress, Gerald R.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/101212

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/101212