Fracture Behavior of Continuous Alumina Fiber Reinforced Epoxy

This work investigates fracture behavior of a continuous alumina fiber (FP) reinforced epoxy under compression at two different temperatures. Effects of fiber orientation, stacking sequence, and temperature on failure mechanisms of the composite material are analyzed through a scanning electron microscope (SEM). Fiber orientation is found to affect the failure mechanisms of the FP/epoxy. While the failure of the 00 laminae is mainly caused by fiber breakage, that of the 90° laminae by sheared epoxy matrix. The [0 2 /90 2 ] s laminates not only have the combined failure modes of the 00 and 900 laminae but also show fiber micro-buckling in the 0° plies and ply delamination at the interfaces of the 0° and 900 plies. Failure mechanisms are found to be different between the symmetric and antisymmetric crossply laminates. In addition, the composites fractured at 77 K display more fiber-matrix debonding, smoother fractured surfaces of fiber and matrix, and cleaner ply delamination at the interfaces of the 00 and 900 plies than the composites fractured at 295 K.