Technical Note: Determination of Impact Noise of Floors Based on Vibration Measurements

2007 ◽  
Vol 14 (3) ◽  
pp. 223-229
Author(s):  
Simone Secchi ◽  
Gianfranco Cellai

Field measurement of acoustical performances of buildings is difficult where construction has not been completed. The absence of doors, windows and other finishing details, generates sound transmission paths, which can modify the results of measurements. In these cases, acoustical performances of building, such as sound reduction index and impact noise, can be determined through the temporary close of all openings, or through the measurement of the vibration velocity level of the partitions examined. Both techniques allow the elimination of airborne transmission paths, while the second also permits the evaluation of the contribution of structural flanking transmission. In this paper, a technique is described for the estimation of impact noise of floors from measurements of velocity levels. Results are presented for a concrete floors and a comparison given between the traditional and new type of measurements.

2014 ◽  
Vol 1057 ◽  
pp. 215-222 ◽  
Author(s):  
Dušan Dlhý ◽  
Peter Tomašovič

The structural complexity of a door causes difficulties in the description of its behavior from an acoustical point of view. In many cases, even a small change can cause a big difference in its sound-isolating properties. To determine the acoustical quality of a door, it is important to perform laboratory measurements of the door structure and door frame, the gaps including. A mathematical analysis based on experimental measurements of the sound reduction index of several door constructions was used to determine the acoustical door categories. The equations for calculating the sound reduction index, which were introduced in this paper, should help in the design of a suitable door from an acoustical point of view.


2021 ◽  
Vol 23 (1) ◽  
pp. 77
Author(s):  
Bondan Dwisetyo ◽  
Maharani Ratna Palupi ◽  
Fajar Budi Utomo ◽  
Chery Chaen Putri ◽  
Dodi Rusjadi ◽  
...  

<p>The implementation of laboratory measurement of airborne sound insulation based on ISO and ASTM standards was carried out at SNSU BSN. The aim of this work to realize the measurement of airborne sound insulation for several sample tests, where the procedure of the test is performed according to the updated standard ISO 10140 and ASTM E90. Besides, the single number rating also is determined based on ISO 717-1 and ASTM E413. This measurement has been conducted in the two reverberation rooms using pressure method consist of measuring the sound pressure level, measuring the reverberation time, obtaining the sound reduction index (R) or sound transmission loss (STL), and determination of a single-number ratings of the samples test. From the results, some parameter requirements such as the frequency range and the rounding procedure of R or STL influence the measurement result slightly. Subsequently, the significant difference is obtained for the determination of single number rating in the shifting procedure of the reference curve.</p>


2017 ◽  
Vol 13 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Jiří Teslík ◽  
Radek Fabian ◽  
Barbora Hrubá

AbstractThis paper describes the results of a scientific project focused on determining of the Airborne Sound Insulation of a peripheral non-load bearing wall made of straw bales expressed by Weighted Sound Reduction Index. Weighted Sound Reduction Index was determined by measuring in the certified acoustic laboratory at the Faculty of Mechanical Engineering at Brno University of Technology. The measured structure of the straw wall was modified in combinations with various materials, so the results include a wide range of possible compositions of the wall. The key modification was application of plaster on both sides of the straw bale wall. This construction as is frequently done in actual straw houses. The additional measurements were performed on the straw wall with several variants of additional wall of slab materials. The airborne sound insulation value has been also measured in separate stages of the construction. Thus it is possible to compare and determinate the effect of the single layers on the airborne sound insulation.


2016 ◽  
Vol 820 ◽  
pp. 443-447
Author(s):  
Monika Pavčeková ◽  
Rastislav Menďan

The contribution presents a mathematical modification of Watters’ formula used in modified Watters’ method. This formula expresses a dependence of sound reduction index on surface mass (mass law). On the basis of the previous research which resulted in the finding that the Watters’ method do not give acceptable results for simple walls from aerated concrete, the mentioned formula was modified to be usable for theoretical determination of sound reduction index of simple aerated concrete walls. The contribution also presents a modification of this formula for calculation of sound reduction index of simple aerated concrete walls with a plaster on both sides.


2019 ◽  
Vol 26 (2) ◽  
pp. 109-120
Author(s):  
AM Shehap ◽  
Abd Elfattah A Mahmoud ◽  
Hatem Kh Mohamed

Nowadays, lightweight building structures are widely used by the construction industry as a more natural and cost-effective method. The purpose of this study is to compare between sound pressure level and vibration velocity method for sound reduction index determination for single- and double-leaf gypsum board partitions. The sound pressure level method was carried out according to the requirements of ISO 140-3:1997, and the vibration velocity method (V) was carried out according to some criteria of ISO 10848-1:2006. Regarding double-leaf partitions, measurements were carried out with the leaves separated by 5- and 10-cm air gaps. The effect of cavity filling with absorbing materials was studied experimentally. The space between the leaves was filled with Rockwool and polyurethane to illustrate the effect of cavity absorption on the sound reduction index behavior. It was found that there is good agreement between the two methods. Also, cavity filling with a 10-cm absorbing material such as Rockwool increases the sound reduction index at the critical frequency by 7 dB using sound pressure method and 4 dB using vibration velocity method.


2016 ◽  
Vol 835 ◽  
pp. 573-578 ◽  
Author(s):  
Naďa Zdražilová ◽  
Denisa Donová ◽  
Iveta Skotnicova

Acoustic properties of building structures are currently very actual theme with regard to the development of new building and insulating materials, while the methods for estimating the airborne sound reduction index evolve mainly from the second half of the 20th century. For mutual comparison of selected prediction methods and for determination of their suitability it has been provided a calculation of weighted sound reduction index RW [dB] from the input parameters of materials identified by laboratory measurements, calculation of weighted apparent sound reduction index R ́W [dB] and these values were compared with in-situ measurements. The aim of this paper is to determine the most appropriate method to calculate RW [dB] and R ́W [dB] values of lightweight building constructions with regard to their practical applicability, accuracy of estimation and complexity of the calculations.


2000 ◽  
Vol 7 (4) ◽  
pp. 315-323
Author(s):  
Francisco Cervera ◽  
Antonio Uris

2016 ◽  
Vol 820 ◽  
pp. 437-442
Author(s):  
Monika Pavčeková ◽  
Rastislav Menďan

The contribution deals with a comparison of measured and calculated values of sound reduction index R (dB) and weighted sound reduction index Rw (dB) of simple walls from various materials. In this way it verifies the exactness of a modified calculation-graphic method according to Watters and an appropriateness of its application for simple walls from various materials with the focus on the aerated concrete walls.


Author(s):  
Y. Taniguchi ◽  
E. Nakazawa ◽  
S. Taya

Imaging energy filters can add new information to electron microscopic images with respect to energy-axis, so-called electron spectroscopic imaging (ESI). Recently, many good results have been reported using this imaging technique. ESI also allows high-contrast observation of unstained biological samples, becoming a trend of the field of morphology. We manufactured a new type of energy filter as a trial production. This energy filter consists of two magnets, and we call γ-filter since the trajectory of electrons shows ‘γ’-shape inside the filter. We evaluated the new energyγ-filter TEM with the γ-filter.Figure 1 shows schematic view of the electron optics of the γ-type energy filter. For the determination of the electron-optics of the γ-type energy filter, we used the TRIO (Third Order Ion Optics) program which has been developed for the design of high resolution mass spectrometers. The TRIO takes the extended fringing fields (EFF) into consideration. EFF makes it difficult to design magnetic energy filters with magnetic sector fields.


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