Damping properties of fibre composite and conventional materials measured by free damped vibration response

Abstract

The present work contributes to the research on the damping properties of fibre composites through an experimental approach by using the free damped vibration measurement based on impulse-force system response, the developed measurement stand and laser Doppler vibrometry. Moreover, the influence of the material configuration on the damping properties was investigated and was compared with conventional homogeneous isotropic materials. The measurement was based on the analysis of flexural vibrations generated by the Dirac impulse force, as well as on the free decaying-vibrations response; the time- and frequency-domain modal identification was employed. The fibre composites were represented as layered bidirectional long carbon- and glass-fibre composites (laminates) with different material configurations and as short carbon-fibre composites.