FATIGUE BEHAVIOR OF THERMOSET AND THERMOPLASTIC CROSS-PLY LAMINATES

This paper compares the fatigue behaviour of two carbon fibre-reinforced plastics (CFRP)-a conventional T300/914 material with an epoxy resin matrix, and the more recently developed material APC2 with a toughened thermoplastic polyetheretherketone matrix. Monotonic and cyclic tensile tests were carried out on [0(7)/90]s and [0(3)/90/0(4)]s cross-ply lay-ups. Under monotonic tensile loading the behaviour of APC2 has been found to be slightly superior to that of T300/914. Surprisingly, during tension-tension fatigue tests, the observed specimen fatigue lives are far shorter in APC2 than in T300/914. Observations of damage evolution in both materials by means of X-ray radiography throughout the fatigue tests and by scanning electron microscopy at the end of the test make these results clearer.