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Volume 18, Issue 3, 2009
EFFECT OF PROCESSING AND LOADING CONDITIONS UPON THE FATIGUE BEHAVIOUR OF A Cf/EPOXY LAMINATE
Christos Koimtzoglou1,3, Konstantinos G. Dassios2* and Costas Galiotis1,2
1 Foundation for Research and Technology Hellas, Institute of Chemical Engineering and High Temperature Processes, Stadiou Street, Platani, Patras GR-26504, Greece
2 Department of Materials Science, University of Patras, Rio GR-26500, Greece
3 Integrated Aerospace Sciences Corporation, 17 Tegeas Street, Argyroupolis, GR-16452, Greece
* Author to whom correspondence should be addressed, E-mail: kdassios AT iceht.forth.gr
ABSTRACT
The current work reports on the tensile and fatigue behaviour of an autoclave-cured unidirectional carbon fibre reinforced epoxy-matrix laminate. The macromechanical properties of the composite are established under interrupted and uninterrupted, static and dynamic conditions at a maximum strain below the critical fatigue limit of the matrix material. The established S-N curve was used to calculate the endurance fatigue limit of the laminate as well as to record an increase in fatigue life of specimens tested at load levels lower than two standard deviations below the mean static strength of the material. The failure modes exhibited by the composite under all testing conditions were recorded and interpreted by means of the damage mechanisms that originate them. The results of interrupted testing showed that the combined effect of fatigue and residence at high stress levels for prolonged periods of time - conditions that simulate a realistic loading scheme- trigger premature fibre failure and thus specimen failure.
Keywords: carbon fibre, fatigue, mechanical testing, autoclave |
