Influence of low temperatures on the phenomenon of delamination of mode I fracture in carbon-fibre/epoxy composites under fatigue loading

This paper, analyses the mode I fracture behaviour under fatigue loading of two aircraft quality composites at different test temperatures. The materials under study are made of the same unidirectional carbon fibre but employ a different epoxy resin matrix. Both composites had the same symmetric configuration [0°]16/s. In the analysis, double cantilever beam specimens were tested at different temperatures: 20 °C (room temperature), 0 °C, −30 °C and −60 °C (different estimated in-flight temperatures aircraft). A fractographic study was carried using a scanning electron microscope (SEM) on samples extracted from specimens previously tested at the different test temperatures in order to analyse their fracture surfaces.