On fracture behaviour of CF/PEKK laminates: Mode I fracture toughness

The interest regarding the use of thermoplastic composite materials in aeronautical structures is increasing in the last years, nevertheless in literature there are few studies concerning the interlaminar properties of CF/PEKK laminates obtained with out-of-autoclave consolidation process. In this work it is studied the interlaminar mode I fracture behavior of laminates obtained from the stacking of a prepreg tape consolidated by heated press. A particular focus is placed on the effect of the pressure applied during the consolidation process of the prepreg, regarding the interlaminar fracture resistance performances of the consolidated material. Three different pressure levels were investigated by testing ASTM D5528 double cantilever beam testing and by an investigation on the material’s microstructure.