Sound absorption of face-centered cubic sandwich structure with micro-perforations

This paper presents a novel ultra-lightweight micro-perforated sandwich structure with face-centered cubic (FCC) core as a sound absorber, which encompasses excellent mechanical features as well as acoustic properties. The structure, which consists of air cavities and small perforations on both the top panel and the corrugated plates, is considered as a combination of multi-layered micro-perforated panel absorbers (MPPAs). A theoretical model that makes use of an equivalent electrical circuit (EEC) approach is established. Validation of the model with experimental results and numerical simulations shows good agreement. The dependence of the acoustic absorption on features of the perforations and of the FCC structure is discussed. Based on the observations, an optimized structure is proposed by using simulated annealing method to yield good acoustic absorption property in the low frequency range.