Effects of temperature on delamination growth in a carbon/epoxy composite under fatigue loading

This paper presents a study of delamination growth in HTA/6376C carbon fibre/epoxy laminates. Tests were conducted under Mode I, Mode II and mixed-mode static and fatigue loading at both ambient conditions and elevated temperature. The results show that the strain energy release rate threshold values for delamination growth under fatigue loading are significantly lower than the critical energy release rates in static tests. At elevated temperature, the threshold values in the fatigue loading were only about 10% of the critical values in the static tests. A fractographic analysis of the delamination growth revealed that the fracture surfaces generated at elevated temperature generally were similar to the fracture surfaces generated at room temperature. Nevertheless, some differences in morphology of the fracture surfaces were observed, and their effect on the static and fatigue delamination growth is discussed in detail.