Vibro-acoustic characteristics of multifunctional carbon fiber reinforced panel

This paper deals with the assessment of vibro-acoustic properties of a multifunctional carbon fiber reinforced panel manufactured by bulk infusion, a modified resin film infusion process. The components of the epoxy resin were chosen to contrast the electrical insulating property and poor flame resistance of the epoxy resins impregnating carbon woven fabric. To confer electrical conductivity to the resin a percentage of 0.5 wt% of Multi-Wall Carbon Nanotubes (MWCNTs) was dispersed in the resin, whereas to increase flame resistance a percentage of 5 wt% of Glycidil Polyhedral Oligomeric Silsesquioxanes (GPOSS) was solubilized in the epoxy mixture. Furthermore, as hardener agents, a mixture of 4,4’-DiaminoDiphenyl Sulfone (DDS) (53.4 wt%) and Bis(3-Aminophenyl) Methyl Phosphine Oxide (BAMPO) (46.7 wt%) was used. The values of the electrical conductivity were found satisfactory enough, being 4.02 × 10−2 S/m for the multifunctional resin and 1.39 × 104 S/m for the in-plane conductivity of the panel, whereas the Limiting Oxygen Index (LOI) value of the multifunctional resin was found to increase from 27% to 36%. Considering these promising results, an experimental assessment of the vibro-acoustic properties of the manufactured multifunctional panel was also performed. The panel was tested mainly to evaluate its low-frequency vibration damping and sound insulation characteristics. The manufactured panel demonstrated an improved efficiency if compared to a baseline configuration, presenting almost the double modal damping and a gain of 10 dB on the global noise reduction.