SONIC CRYSTAL ACOUSTIC BARRIERS BASED ON SCATTERERS WITH ADDED ACOUSTICAL PROPERTIES

摘要

Scatterers with added acoustical properties are used in this work to improve the attenuation capabilities of Sonic Crystal Acoustic Barriers (SCAB). Perforated rigid cylinders add an additional independent periodicity to the SCAB introducing attenuation peaks in the range of low frequencies above the Band Gap of the structure. Band Structures calculated by Finite Element Methods are in good agreement with the experimental results showing the attenuation bands of SCAB made of perforated scatterers. Rock wool scatterers are also used to produce a certain level of attenuation along a wide range of frequencies exploiting the absorbent properties of this material. We present experimental evidences for the improvement in the attenuation properties of the SCAB in the range of low frequencies when we combine perforated cylinders with absorbent materials.