Abstract
The use of Sonic Crystals as acoustic screens, usually called SCAS (Sonic Crystal Acoustic Screens) has meant a qualitative jump in the field of environmental noise protection. This technological achievement, developed over the last decade, has been accomplished in two steps: the discovery of the basic knowledge about physical principles underlying in the behaviour of these periodic systems and the development of technological procedures for designing and constructing this kind of acoustic screens in such a way that be competitive, under the acoustic point of view, with respect to the classical barriers. In this sense, among all the fields where these periodic systems can be applied, the one referred to acoustic screens has been the first where a device has been designed, patented, constructed and standardized with fairly good results. However, the development of specific software to design these devices in a professional way is a pending subject to introduce them successfully in the market. Following this line, in this paper we present an overlapping comprehensive model to easily design SCAS. The model has been implemented using the Finite Elements method and is based on the tunability concept, which stablish that all the acoustic effects involved in the design act independently one from each other, and furthermore works constructively. This fact allows the design of barriers for specific purposes, assigning to each acoustic effect a predetermined range of frequencies where it has to work. An example in the use of this model is applied to the case of the reduction of diffraction at the upper edge of a SCAS
