Holes Interaction and Heterogeinity Distribution Effect for a Multiperforated Plate
Résumé
Originally used to protect classical sound absorbing materials from environmental degradation, multi-perforated plates are considered to be one of the next generation soundproof solutions. This paper investigates the effects of holes interaction and heterogeneity distribution on the acoustical properties of a multi-perforated plate. These effects are observable on the specimens with closely separated holes. Multi-perforated plates with different center-to-center holes distances (pitches) are built and tested using an impedance tube. The cases of closely separated holes are analyzed and compared to the cases of widely separated holes. It is observed that in the presence of these effects, both the acoustical parameters are modified. The resonance frequency is observed to decrease toward the low frequency ranges. The effective mass density increases with a decrease of the pitch. The results of this work can be used for designing optimal perforated panels for ducts, silencers and for the automotive industry.