Lecturer, Imperial College of Science, Technology & Medicine, London,
Pages: 9 Published: Jan 1997
The present work examines the effect of resin ductility (varied as a function of temperature) on the compressive strength of unidirectional T800/924C carbon fibre-epoxy laminates. Tests are conducted in a screw-driven machine between room temperature and 100°C. Untabbed straight-sided specimens are used in a modified Celanese test rig; conventional serrated grip faces of the Celanese jig are replaced by spark-eroded inserts to eliminate adhesively bonded tabs on the specimen ends and minimize gripping region failures. Test results show that at approximately 80°C the failure mode switches from in-plane to out-of-plane fibre microbuckling. As the test temperature increases, the shear strength/stiffness of the resin is considerably reduced; this decreases the amount of side support for the fibres and reduces the strain level at which fibre buckling occurs. Recent fracture models are used to predict the compressive strength of the T800/924C system; agreement between theory and experiment is acceptable.
carbon fibre composite, temperature effects, shear properties, compressive strength, fibre misalignment, fibre microbuckling, failure analysis
Paper ID: STP18275S