Airborne noise calculation for single-layer partitions with the concentrated parameters method

Abstract

Abstract The article considers an approach to the calculation of sound insulation for building partitions with the method of concentrated parameters at the standard frequency range, which is specified in regulatory documents. The concepts of “reduced” and “concentrated” masses are introduced for objects that are sound conductors. It is noted that the physical model of sound insulation in the three conditionally allocated frequency ranges of the standard spectrum has differences. The calculated equations of sound insulation for three frequency ranges are given. Systems of equations for obtaining the calculation formulas at the first and the second frequency ranges are used. The systems consist of equations for the conservation of the amount of motion and the conservation of kinetic energy. The influence of the damping effect of air and resonant phenomena in the plate on the final value of sound insulation is described. The nature of sound propagation in the third frequency range is considered, in which, unlike the first two sections of the frequency spectrum, where the propagation of flexural waves is mainly recorded in the plate, shear and dilatational vibrations have a predominant influence on the sound insulation level. Examples of graphs for massive partitions obtained by the considered method are given. The accuracy of the proposed method is evaluated in comparison with the normative code’s method and the method based on the theory of self-matching of sound fields. A general algorithm for calculating sound insulation in the entire standard frequency range is presented.