High cycle vibration fatigue of CFRP under elevated ambient temperatures

Vibration Fatigue of Carbon Fibre Reinforced Polymers (CFRP) composite components couples both the thermal and the mechanical properties of the material. In fact, the fatigue life depends greatly on capacity of these properties to change according to both input load and environmental conditions. The mechanical properties are related to the change of the structural stiffness at a given input load while the thermal behaviour is associated to the dissipation of the input force either by hysteresis or by ply - by - ply friction forces in damaged regions. This paper will be primarily focussed on the experimental investigation of the coupling between the mechanical and thermal properties. Experiments focus on the relationship between response phase and the thermal life (self - heating) of composite specimens under different environmental temperatures up to early crack propagation. It will also explore the effect of the temperature during the early crack propagation.