On some problems related to the fabrication of a metallic micro-perforated panel for noise control applications

Micro-Perforated Panels (MPP) are widely used nowadays as a noise control solution. Such materials present many interesting advantages and are considered to be among the latest innovative sound absorbing materials. For these reasons, many models are proposed in the literature to predict their acoustic behavior. However, the accuracy of these models depends on the assumptions under which they are derived and more often on the MPP samples built for their validation. Rigorous attention is therefore needed to insure convenient fabrication of samples for the MPP. This paper investigates some important problems related to the fabrication of metallic MPP samples used for noise control applications. Particular emphasis is given to the hole drilling effects. It is shown for instance that the presence of shavings inside the perforation may alter or change the MPP acoustic response. This work supports the design of optimum MPP for noise control applications such as duct mufflers, room acoustics, and transport domain and environment noise abatement.