DYNAMIC CHARACTERISTICS OF THERMOPLASTIC COMPOSITE LAMINATES

Dynamic characteristics of carbon fibre/polyetheretherketone (CF/PEEK) composites have been investigated by the impact test and the sinusoidal free vibration test. Using a cantilevered beam with rectangular cross-section, the natural frequencies and damping properties were measured. Also, dynamic tests for the cantilevered beam with a torsional bar have been performed to identify the shear modulus and damping in torsional motion. Results for the specific damping capacity given by the impact test are very close to those given by the sinusoidal vibration test. The elastic moduli from the impact test are slightly smaller than those from the tension test. The dynamic characteristics of angle-ply, cross-ply and quasi-isotropic laminates have been computed by the finite element method. For the purpose of verification, experimental tests were carried out by the impact test for these laminates. The experimental values are very close to the numerical values. In addition to CF/PEEK composites, experiments have been performed for CF/epoxy composites. The damping Of CF/epoxy is much larger than that of CF/PEEK.