Calculation Of Sound Insulation Research Articles

Calculation of Sound Insulation for Hybrid CLT Fabricated with Lumber and LVL and comparison with experimental data.

The insulated predictions were carried out for LVL, CLT and HCLT in order to evaluate their sound properties, in which the theoretical value of sound insulation was predicted by regarding the substances in wood cell wall as equivalence to specific medium based on Biot model, and the wood anatomical characteristics, such as the length and diameter of tracheid, diameter of pit, and porosity, were taken into account for determining the equivalent density and bulk modulus of elasticity of wood cell wall. By comparing the tested and predicted values of sound insulation, the conclusion were drawn as follows: the predicted values of sound insulation were significantly correlated with the tested values for LVL, CLT and HCLT. As for Masson pine and Southern pine, the adjacent of earlywood and latewood was considered as sandwich structure for the calculation of sound insulation. Meanwhile, the bonding interface was creatively introduced to improve the accuracy of sound insulation prediction. The transfer function involved in sound insulation prediction provide an effective method to characterize the sound insulation volume of wood composite in construction and decoration areas.

Applying Immune Algorithems to the Calculation of Sound Insulation of Walls

Building wall plays a key role in the noise isolation. As a there are lot of open holes in the wall for various construction equipments, pipes and lines, it is an important issue how to determine the maximum area of wall cracks with the given expect sound insulation. The calculation model is established with immune algorithm, the expected value of the sound isolation is defined as objective function, the areal density, thickness and Young modulus of monolayer wall are defined as bounded variable. The global maximum value of objective function is obtained by the MATLAB program and so to determine the materials, thickness and construction details which reach to the sound insulation.

Method for measuring the sound insulation of facades: Factors to be considered

The paper is a general introduction into possible ways in which the sound insulation of facades could be measured. Examined are direction of measurement, noise source, sound pressure levels measurements and calculation of sound insulation.

Calculation of sound insulation of barrier constructions in buildings with regard to flanking transmission

This paper presents a calculation of the amount of increased noise level in a room due to flanking transmission and of the largest attainable value of sound insulation of the room when the additional sound insulation of a barrier construction is as large as possible. Vibration transmission coefficients through junctions of barriers are calculated for some of the simplest building constructional configurations. The calculated values are in good agreement with experimental measurements.

Measurement and Calculation of Sound Insulation

The term “reduction factor” has been given different meanings. Architects, builders and even many acoustical engineers, are not aware of these different meanings, and consequently unnecessary confusion arises whenever insulation data from different laboratories are compared. Thus, the “reduction factors” for the same type of panel measured at the Bureau of Standards and at the Riverbank Laboratories may differ as much as fifteen decibels. Buckingham and also Davis have shown that the quantities measured at different laboratories cannot be directly compared. However, these quantities may be converted into quantities—the coefficients of transmission for the panel—which do admit of direct comparison. Under suitable test conditions these coefficients should be independent of the test room and also of the method of testing. The writer has made some insulation measurements by three different methods—typical of the methods now in use at different laboratories—and obtains good agreement for the coefficients of transmission by all three methods. By assigning reasonable properties to the test rooms at the Riverbank Laboratories it is shown that Sabine's results on the insulation of rigid partitions are in essential agreement with Chrisler's results. A simple formula is suggested for calculating the insulation properties of rooms.