Damping wave propagation in periodic composite panels

Composite structures have been introduced in the transportation industry to reduce vehicle mass and energy consumption. Composites have low internal damping which leads to higher levels of vibration and induced noise. To reduce the vibrations amplitude and thus the acoustic discomfort, damping elements placed in specific locations of the structure are sometimes used. The integration of these elements to optimize the structure is often complex, costly, and may cause a delay in product delivery. In order to avoid curative treatments, another solution is to incorporate anti-vibration function at the design stage of the composite material. In this paper, the anti-vibration function is obtained by the introduction of periodic effect. The use of periodicity allows to stop wave propagation in a given frequency range, called band gap. The vibro-acoustic properties of the structure are thus improved.