Dynamic characteristics of AS4/PEEK composites are investigated by the impact test and the sinusoidal free vibration test. Using a cantilevered beam with rectangular cross section, the natural frequencies and the damping properties are measured. Also, the dynamic tests for a cantilevered beam with torsional bar have been performed to identify the shear modulus and the damping in torsional motion. The results for the specific damping capacitance by the impact test are very close to those by the sinusoidal vibration test. The Young's modulus by the impact test are slightly smaller than that by the tension test.
The dynamic characteristics of angle-ply, cross-ply and quasi-isotropic laminates are computed by the first-order shear deformable theory. For the purpose of verification, experimental tests are carried out by the impact test for those laminates. The experimental values are very close to the theoretical values.
In addition to the AS4/PEEK composites, the experiments for the HFG/Epoxy composites have been performed. The dynamic characteristics of the two composite materials have been compared. The damping of HFG/Epoxy is much larger than that of AS4/PEEK.