Study on Mechanical Properties of Carbon Fiber Reinforced Polyether Ether Ketone Composites

Uniaxial tensile tests are performed on polyether ether ketone (PEEK) resins and carbon fiber/polyether ether ketone (CF/PEEK) composites. The ratcheting behavior of the CF/PEEK composites under stress-controlled cyclic loading is studied using a combined experimental and finite element approach, with a particular emphasis on the effects of mean stress and stress amplitude. Based on the constitutive relation parameters obtained from the uniaxial tensile tests, a representative volume element model of the CF/PEEK composite is built using ABAQUS and the random sequence of adsorption (RSA) algorithm. The experimental results and numerical simulations are compared under the same loading conditions, revealing that a noticeable ratcheting occurs in the composites under asymmetric stress-controlled cyclic loading and that this is related to the stress amplitude and mean stress. Moreover, good agreement between the experimental results and simulation is achieved in this study,. demonstrating that the finite element simulation is an accurate method to predict the ratcheting strain in CF/PEEK composites under different conditions.