Vibro-acoustic analysis of additively manufactured acoustic metamaterial via CUF adaptive finite elements

Abstract. In the field of noise and vibrations control inside the cabin, passive noise solutions coupled with the development of new unconventional materials, called Acoustic Metamaterials (AMMs) can be very promising to stop incoming noise and guarantee the passenger’s comfort without an increase in aircraft weight. Within the framework of Carrera’s Unified Formulation (CUF), we study the acoustic properties of double pierced AMM plate printed with Fused deposition modelling technique (FDM). The influence of several geometrical parameters is investigated, such as the size and location of the holes and the perforation ratio. The properties of this AMM are derived from vibro-acoustic analyses of the finite element software, Mul2, developed by Politecnico di Torino, that exploits the CUF. In order to study the AMM complex structure in the CUF framework, the Adaptive finite elements are exploited. This new class of 2D elements, recently developed, allows us to model with shell elements the AMM structure, which presents several discontinuities in the mid-surface due to the presence of corners and internal cavities.