High temperature fatigue of carbon/polyimide 8-harness satin woven composites. Part II: Environmental effects

This paper focuses on high temperature fatigue of Carbon/polyimide 8-harness satin woven composite materials. Traction-traction (R = 0.1) fatigue tests at 250 degrees C are carried out on Carbon/polyimide [45](6) 8-harness satin woven composites under three different environments (air, 2 bar N-2, 2 bar O-2). Part II is specifically devoted to the study of the environmental effects occurring during high temperature fatigue: strain, mechanical properties and damage evolution are characterized by Digital Image Correlation (DIC) and mu-Computed Tomography (mu CT) techniques. The rich characterisation of damage extent and orientation can be naturally integrated within the context of a damage-dependent behaviour models. The effect of the environment is assessed through a description of thermo-oxidation phenomena occurring at high temperatures.