In situ compressive behavior of carbon fibers reinforced PolyEtherEther Ketone laminates exposed to one-sided heat flux

This study investigates the influence of a combined thermal heat flux (imposed by a cone calorimeter) and a compressive loading on the deformation and damage mechanisms within quasi-isotropic carbon fibers reinforced PolyEtherEther Ketone laminates. Thermogravimetric Analyses conducted at increasing heating rates under nitrogen (from 5 to 500°C/min) provide valuable information on the thermal decomposition of C/PEEK that ranges from 550°C to 627°C, with a corresponding mass loss ranging from 20 to 26%. From the thermo-mechanical coupling standpoint, the softening and the thermal decomposition of the PEEK matrix under a 50 kW/m2 heat flux result in the micro-buckling of fibers bundles in matrix-rich areas at the ply scale. Ultimately, it leads to the formation and propagation in the transverse direction of plastic kink bands at the laminates scale. Post-failure observations show that this macroscopic kinking propagates specifically according to the PEEK matrix pyrolysis.