Sound insulation design of the thin partitions on the base of concentrated parameters model

Abstract

Introduction. The theoretical and practical approach on the base of the discrete parameter's method to the acoustic insulation of the thin partitions by Candidate of Science, Prof. Zakharov A.V. is given in this issue. The method allowed to develop a logically conclusive and consistent physical airborne sound insulation model for one-layered massive and light partitions either. This issue concentrates on providing of the engineer calculation technique of the sound insula-tion for the thin partitions and, also, on comparison of the technique's results with the computations by the current normative documents. Materials and methods. The application of the same “Mass Action Law's” formula both for the normal and the oblique noise wave's incidence on the sound isolating plate, regardless the sound waves angles, is mathematically and physically approved. The essence of the concentrated parameters, such as concentrated and reduced material's mass, is revealed. The equations of momentum conservation law and kinetic energy conservation are used to obtain the coefficient of the oscillation velocity transmission. The formulas for airborne sound insulation at the diapasons before and after the sound wave's coincidence frequency are written. Results. The damping air property's influence on the thin partition's sound insulation is considered, and it's formulas are represented. The formulas for taking into account the reduction of sound insulation at the resonances in sound protective slab or in a partition are also given. The general equation for the thin partition's sound insulation by the method of localized (discrete) parameters are derived. The example of detailed calculation of the sound isolation of the thin asbestos-cement partition is demonstrated. The comparison between the medial three octave deviations of the sound isolation values and the experimental results in case of the SP (Russian normative document) method and in case of the introduced author's method for the different construction materials is represented. Conclusions. The proposedsound insulation calculation method for the thin light partitions, which is based on the concentrated parameters model, gives very close to experiments results. So, it enables to find the insulation figures across the entire standard frequency range, according to the initial physical and technical materials' and constructions' features.