The prediction of the vibration reduction index Kij for brick and concrete rigid junctions

2010 ◽  
Vol 71 (6) ◽  
pp. 523-530 ◽  
Author(s):  
Alessandro Schiavi ◽  
Arianna Astolfi
2008 ◽  
Vol 123 (5) ◽  
pp. 3615-3615
Author(s):  
Arianna Astolfi ◽  
Alessandro Schiavi ◽  
Cristiana Taricco ◽  
Simone Geroso ◽  
Fabrizio Bronuzzi ◽  
...  

2006 ◽  
Vol 13 (2) ◽  
pp. 99-111 ◽  
Author(s):  
Charlotte Crispin ◽  
Bart Ingelaere ◽  
Manuel Van Damme ◽  
Debby Wuyts

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
J. Alba ◽  
E. Escuder ◽  
J. Ramis ◽  
R. Del Rey ◽  
E.G. Segovia

This paper describes the procedure followed to evaluate the vibration reduction index for T-junctions with inserted flexible elements and proposes new equations to complement the standard EN 12354-1:2000. The experiment described in this work is based on a 1:3 scale model of a T-junction with a flexible interlayer. It was used to obtain a significant reduction in the cost of the configurations under study. We chose to carry out vibration measurements by near-field acoustic holography (NAH) in order to avoid the risk of accelerometer interference. Flanking transmission was determined for different elastic layers with the objective of quantifying the effect of the flexible interlayer and to compare the results obtained with predictive formulas. The results enabled us to propose new equations to complement EN 12354-1:2000 for the reliable prediction of the apparent sound reduction index. The uncertainty associated with the different average velocity levels is determined according to the Guide for the Expression of Uncertainty of Measurement (GUM).


2012 ◽  
Vol 37 (2) ◽  
Author(s):  
Jaime Ramis ◽  
Enrique Segovia ◽  
Jesús Alba ◽  
Jesús Carbajo ◽  
Luís Godinho

2018 ◽  
Vol 25 (4) ◽  
pp. 363-376 ◽  
Author(s):  
Rui Calejo Rodrigues ◽  
Dóris Queirós ◽  
Elsa Caetano

Historical old buildings bring together a whole set of unique characteristics with substantial influence on the acoustic behaviour, especially concerning the junctions between light and heavy elements, as is the case with wooden floors and stone masonry walls. The lack of information about the acoustic characteristics of wooden structures leads to the use of theoretical prediction methods, which do not accurately represent real conditions. The wooden floor’s complex design hampers the study of its acoustical behaviour. This difficulty becomes greater when the analysis targets the structural systems instead of the single elements. Consequently, the need of a deeper knowledge about the characteristics which influence the acoustic behaviour of these junctions leads to the research on the acoustic component associated with the flanking transmission paths of airborne sound – vibration reduction index ( Kij). Structural reverberation times ( Ts) for both elements were acquired in order to feature the in situ real condition. ISO 10848-1 standard procedure was followed for both measurements. In situ flanking transmission measurements between wooden structural floors and stone masonry walls will allow their comparison with theoretical prediction methods, as defined by the EN 12354-1 standard method. Results show a great deviation between in situ measurements of the vibration reduction index ( Kij) and the obtained results for the same index through theoretical models.


2009 ◽  
Vol 16 (3) ◽  
pp. 199-231 ◽  
Author(s):  
Jeffrey Mahn ◽  
John Pearse

Equations to calculate the uncertainty of the EN12354-1 estimate of the flanking sound reduction index due to the uncertainty of the input data are derived using the method of the ISO Guide to the Expression of Uncertainty in Measurement (GUM). The uncertainty equations have been validated using Monte Carlo simulations. It is shown that the magnitude of the uncertainty depends on the uncertainty of the resonant sound reduction indices of the elements, the uncertainty of the vibration reduction index and the uncertainty of the equivalent absorption lengths and areas of the elements. However, equations could not be derived to calculate the uncertainty of the EN12354 estimate of the apparent sound reduction index which has a lognormal probability density function and is therefore outside of the scope of the method of GUM. Monte Carlo simulations must be used to calculate the uncertainty of the apparent sound reduction index. It is recommended that guidance for calculating and declaring the uncertainty is included in future versions of EN12354, ISO10848 and ISO15712.


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