Measuring the intralaminar crack resistance curve of fibre reinforced composites at extreme temperatures

This work focuses on the development of methods to measure the intralaminar fracture toughness of IM7/8552 CFRP at extreme temperatures. The size effect law of scaled double-edge-notched (DEN) specimens is used to obtain the crack resistance curves associated with longitudinal failure of polymer composites. The compressive and tensile crack resistance curves are determined and compared to those measured at room temperature. Scanning electron microscopy is used to analyse the fracture surface of tensile DEN specimens as a means to understand the damage mechanisms involved and their dependence on temperature variations. It is shown that the methods proposed enable the measurement of the crack resistance curve under different environment conditions. The results obtained can be used in analytical models to evaluate the integrity of composite structures at extreme temperatures.