Experimental investigations into sound transmission loss by different materials at aircraft noise

In this paper, the sound transmission loss by different materials at aircraft noise is measured experimentally. The main objective of this paper is to measure the acoustical or sound absorption properties of glass material, polypropylene material and glass fiber reinforced composite material. The composite material is manufactured at three different fiber volume fractions. The fiber volume fractions are 10%, 20% and 30%. A three dimensional wooden sound proof duct is manufactured in which a long duct is enclosed. An acoustic source is used to generate an aircraft noisy signal. The generated signal is passing through the samples of the different material to measure their sound absorption properties. It is observed that for each fiber orientation, glass material is absorbing more aircraft sound than neat polypropylene and composite specimens. It is concluded that composite material with 10% volume fraction of fiber is performing better than the rest of specimens. This is due to the fact that with the increase in volume fraction of fiber, porosity decreases due to which sound transmission loss decreases. Also, the sound transmission loss of composite specimen with 10% volume fraction of fiber is comparable with that of the glass material. (c) 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Materials, Processing & Characterization.