Acoustic Reflection and Transmission Properties of Several Transducer Window Materials

The transmission, reflection, and absorption characteristics of a material largely determine its usefulness in underwater sound applications. Uses may include transducer windows, sonar domes, sound reflectors, and linings for test tanks. Most of the experimental data available in the literature are for normal incidence of a plane wave on the material. However, in some applications it is desirable to know the acoustic properties of a material for angles of incidence other than normal. For these reasons a test system was devised to experimentally determine the acoustic properties of materials over a wide range of incident angles. Theoretically, the most straightforward approach to the case of arbitrary incidence is found in Brekhovskikh. The expressions for transmission and reflection coefficients will be used to compare theory and experiment. Hence it is the purpose of this paper to experimentally determine these coefficients for Absonic-A, Plexiglas, Soab, Polyethylene, and Fiberglass for frequencies ranging from 100-500 kc, compare the results with theory, and then examine their usefulness in underwater sound applications based upon these results.