The fracture behavior of hybrid carbon and glass fiber woven-ply reinforced polyether ether ketone thermoplastic quasiisotropic laminates is investigated. Single-edge-notch bending and single-edge-notch tensile tests were conducted at room temperature and at a temperature higher than the glass transition temperature (T g) to study the influence of both the constraint effect and the temperature on the strain energy release rate in laminates with ductile polyether ether ketone matrix and brittle fibers. As failure is primarily driven by fibers breakage in tension (single-edge-notch tensile test) and in tension/compression (single-edge-notch bending), it turns out that a temperature increase has very little influence on the mode I critical translaminar fracture toughness K Ic though the ductility of polyether ether ketone matrix is exacerbated at T > T g. It also appears that the constraint effect has very little influence on K Ic as single-edge-notch tensile test and single-edge-notch bending specimens have virtually the same mean value (about 45MPa. m p). Single-edge-notch bending specimens being characterized by a gradual failure, the G-R curves were derived from the computation of the compliance loss and the corresponding gradual crack growth in agreement with the ASTM standard E1820. From the evolution of the G-R curves at high temperature, the highly ductile behavior of the polyether ether ketone matrix at T > T g provides a good intrinsic toughness to the material, and the bridging of translaminar crack by the glass fibers at the outer surfaces of laminates contribute to a moderate increase in its extrinsic toughness.

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This paper is intended to test the capacity of a simple model based on fracture mechanics concepts to predict the ultimate strength of notched hybrid carbon and glass fibers woven-ply reinforced PolyEther Ether Ketone (PEEK) thermoplastic (TP) quasi-isotropic (QI) laminates under different temperature conditions. In such materials, translaminar failure is the primary failure mode driven by the breakage of 0°and 45°oriented fibers in tension as well as the formation of kink-band in compression. Single-Edge-Notched Bending (SENB), Open-Hole-Tensile (OHT) and Open-Hole-Compression (OHC) specimens have been conducted at room temperature (RT) and at a temperature higher than the glass transition temperature (T g). The Critical Damage Growth model derived from the Average Stress Criterion and Linear Elastic Fracture Mechanics (LEFM) have been applied to open-hole specimens to determine the critical damage zone from which the fracture toughness in tension (0°and 45°fibers breakage) K Ic tension and in compression (kink-band formation) K Ic comp. are estimated. In Single Edge Notched Bending (SENB) specimens experience simultaneous tension/compression. From the estimation of K Ic tension and K Ic comp. , the ultimate strength of SENB specimens can be predicted. LEFM equations combined with the critical fracture toughness in tension give relatively accurate results, suggesting that failure is driven by fibers bundles breakage in tension.