ASA 126th Meeting Denver 1993 October 4-8

4pEA6. Noise attenuation provided by flexible shields for industrial equipment.

Natalia V. Sizova

Cooperative Inst. for Res. in Environmental Sci., Campus Box 216, Univ. of Colorado, Boulder, CO 80309-0216

A general physical model and method for the calculation of the noise reduction provided by a flexible shield consisting of thin, rigid, narrow plates, joined together lengthwise into a chain is represented. The model selected is one plane containing a set of linear rectangular plates placed side-by-side, separated by narrow spaces. All plates are making flexural oscillation under the influence of evenly distributed noise pressure. The model is based on the determination of the sound pressure caused by sound radiation of a thin rectangular rigid plate in average frequency range (63--8000 Hz), in far field. The loss factor of the plates junction was determined experimentally and used for the calculation of the noise reduction. Some experimental data for the noise reduction provided by different designs (different number of the plates, material, thickness) were represented and compared to the calculated results. The method allows to determine the optimal parameters which are necessary to achieve maxima of the noise reduction. [Work supported by Scientific-Research, Institute of Printing Machinery, Moscow.]