ARCA

Optimization of the Acoustic Characteristics of Composite Materials for Aeronautics

IMAST members involved:

Objective:

In civil aeronautics, the use of composite materials applied to parts of the primary fuselage structure makes significant weight reductions possible while maintaining the same structural performance. These materials, however, are somewhat lacking in terms of acoustic characteristics, because they are particularly permeable to noise in the passenger cabin, with a consequent significant reduction in the level of comfort. The ARCA research project aimed to develop innovative composite materials with improved acoustic characteristics compared to traditional composites, while still ensuring compliance with mechanical-structural and process requirements. The types of material modification investigated were:

  1. the insertion of a layer of damping material (“damping layer”) inside the different layers of which the composite material is made;
  2. the addition of damping material fibres within the single layer of the composite;
  3. the addition of nanomaterials at the matrix and/or fiber level

Furthermore, innovative acoustic treatments inside the cabin have been explored, produced with polymeric materials of various compositions, also using active control techniques, in order to maximize performance as absorbers or dampers of acoustic and/or vibration energy.

Objective achieved:

The best results were obtained with the damping layer configuration. In particular, a stringerized panel has been created with better capacity to absorb and dissipate vibro-acoustic energy than current systems (-3dB), with a consequent reduction in the noise perceived by passengers on board. This panel offers good structural properties while reducing weight by 60%, resulting in lower fuel consumption and pollutants.
Furthermore, multidisciplinary expertise (materials, modeling and design, vibroacoustic testing) has been acquired, as well as a database virtually unique in the international scientific community.

Performance indicators:

  • 209 researchers involved (20% women and 12% new project contracts) with an average of 50 per year
  • 22 researchers hired on a permanent basis following the project
  • 14 scientific publications
  • 1 patent