A study of the damage accumulation process in poly(aryl ether ketone ketone) and its AS4 carbon fiber reinforced composites

This thesis presents the results of a study done on the damage accumulation process in poly(ether ketone ketone) and its AS4 carbon fiber reinforced composites. The damage accumulation process was studied as a function of applied heat treatment. This study is the result of a project funded by duPont and was done in part to explain the dramatic change in fatigue properties observed at duPont as the applied heat treatment is changed. The mechanical properties were characterized using a battery of tests. The quenched composite systems have lower moduli, but higher toughness and elongations. The quenched systems also have the best fatigue performance and therefore, it can be concluded that the quenched composite systems have the best potential as far as industrial applications are concerned. Quenching has other advantages in industrial applications. These include decreased chances of operator error, and decreased processing times. The damage accumulation process was characterized using the acoustic emission method and also the drop in stiffness during flexure testing. It has been observed that the ultimate mechanical properties show a weak dependence on the applied heat treatment, whereas the damage accumulation process changes dramatically. A model has been developed to simulate the damage accumulation process. This model has then been used to predict the fatigue S-N curve in stroke control and to qualitatively relate it to the available fatigue data in stress control.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Materials Science and Engineering

Department dc:contributor.department

Materials Science and Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1992

Author dc:creator

• Verma, Ravi Kant

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-06112009-063316

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/43146