Experimental investigation of the effect of material on the non-linear properties of perforated plates

Perforated plates are one of the effective passive noise controllers in the aeroacoustics system and industry. Effective absorption, resistant in harsh environment and easy maintenance are main reasons for perforated plates having several applications. Literature shows that even though perforated plates are common sound absorbers, they can be relatively easy non-linear. There are many reasons for this, for instance, temperature, and high level sound pressure. High sound pressure level can have non-linear impact at fairly low levels. Therefore, identification and understanding of this phenomenon is important. This is an essential reason for this study to experimentally investigate perforated plates with different material and study the non-linear properties of them. Two perforated plates with different material, fiberglass and steel, have been studied. The results illustrate that the geometry such as perforation, its thickness and the perforated plate material affect the non-linear properties of the perforated plate.