Effects of Stacking Sequences on the Interlaminar Shear Strength of CF/PEKK Composites

High performance thermoplastic composites for aerospace primary structures are increasingly studied in the last years. However few articles report the properties of the PEKK/CF composite material for structural applications. In this paper the Interlaminar Shear Strength of laminates obtained with different stacking sequencies of unidirectional layer obtained from a PEKK/CF prepreg tape was evaluated. A modification of the ASTM D2344 standard is proposed for obtaining a valid failure mode, considering the less brittle behaviour of the thermoplastic matrix compared to thermosets. Furthermore, this testing campaign was carried out performing a 2D Digital Image Correlation. Results show how, the modified testing parameter are crucial to obtain shear failure mode for the considered carbon fibre reinforced thermoplastic composite.