THICKNESS INFLUENCE ON ABSORBING PROPERTIES
OF STRATIFIED COMPOSITE MATERIALS
IULIANA IAÈNICU [STAMATE] 1, OVIDIU VASILE 2, RADU IATAN 3 1. Gheorghe Asachi Technical College, Bucharest, 24 Aleea Pravat, sector 6,
061 569 Bucharest, Romania
2. Department of Mechanics, University Politehnica of Bucharest, 313 Splaiul Independentei, sector 6, 060042 Bucharest, Romania
3. Department of Process Equipment, University Politehnica of Bucharest, 313 Splaiul Independentei, sector 6, 060042 Bucharest, Romania
Plates known as sound absorbing materials: textiles recovered fabrics plus polyethylene are made layered composite material intended to be used to encapsulate industrial engines, as sources of noise in the production departments. Influence of thickness sound-absorbing material can be supported by the values obtained for the absorption coefficient, but it can be studied as a study case in the anechoic chamber, where the sound pressure level is measured with a sound level meter. Cases captured: a free engine; the engine placed in a metallic cube and motor inserted; metal cube that was doubled separately with one material and then with the composite material proposed. For each situation are eight determinations on the perimeter of a circle with a radius of one meter from the source of the noise. Plot a graph of experimental results that support the idea: greater thickness of the layer of material will cause a better absorption of noise.
