Biaxial Flexural Testing of a Carbon Fiber Reinforced Epoxy Composite

Abstract

The response of a 3501-6 resin composite to biaxial flexural loading was assessed using disk specimens. The composite was cross-ply reinforced with continuous carbon fibers with a volume content of 60%. Under monotonic flexural loading the formation of delaminations limited the useful range of the composite's deformation to a biaxial tensile strain of 0.0067. Under cyclic flexural loading and for a fatigue life of 106 cycles, the useful strain range was limited to 0.003. The latter strain is only 19% of the composite's uniaxial tensile strain to failure. Fatigue failure mechanisms included delaminations, matrix cracking, fiber and possibly bundle debonds. Some delaminations were identified with ultrasonic C-scanning