Damage characterization during high temperature fatigue of off-axis woven organic matrix composites for aircraft applications

The present work focuses on damage characterization during high temperature fatigue of 8HS woven [45]6 carbon HTS40 carbon fibre/polyimide matrix composite samples. Fatigue tests are performed under controlled environment (air, 2 bar O2, 2 bar N2) at 250°C by using a specific experimental setup developed at PPRIME Institute; Digital Image Correlation (DIC) and μ-Computed Tomography (μCT) are used for monitoring the evolution of sample behaviour during fatigue. It is shown that these two techniques are effective and complementary for damage assessment under fatigue at high temperature under aggressive environment: a rich characterisation of damage extent and orientation can be provided which allows damage being formalised in a way that can be naturally integrated within the context of damage-dependent behaviour models. The employment of such description allows performing full assessment of the effects of environmental fatigue.