Comparative Study of the Influence of PPS, PAEK, and PEEK Thermoplastic Matrices on the Fatigue Mechanical Behavior of Carbon Fiber Reinforced Composites

ABSTRACT Structural thermoplastic composites have attracted increasing interest in engineering applications due to their excellent mechanical properties and recyclability. This work aims to contribute to this field by investigating the influence of poly(ether ether ketone) (PEEK), poly(aryl ether ketone) (PAEK), and poly(phenylene sulfide) (PPS) matrices on the fatigue behavior of carbon fiber (CF) composites. The findings indicate that the CF/PEEK composite has a fatigue limit in the range of 420 to 450 MPa, CF/PPS between 405 and 445 MPa, and CF/PAEK tends to form a plateau, suggesting a possible limit between 430 and 460 MPa. Although the results suggest differences in fatigue performance among the materials, the data do not allow a definitive determination of fatigue limits for each system, particularly for CF/PAEK, which requires additional tests. From an engineering perspective, a conservative fatigue stress level of 400 MPa is proposed for safe use and infinite life of these laminates.