Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

When the neighbor's noise makes its way through the walls

07.11.2008
Architectural acousticians of the PTB have discovered the chink in the sound insulation value analysis

Some people know more about their neighbors than they would like to. Whether the other tenants are just now listening to music, watching television, having visitors, vacuum cleaning or washing clothes - its not possible to not overhear these things, because sound finds its own way.

Only the best possible insulation of the walls helps here. Manufacturers of partition walls will possibly have to think further ahead in future than they have up to now: Christoph Kling shows in his dissertation at the Physikalisch-Technische Bundesanstalt (PTB) that the repercussion of sound from adjoining walls has previously been taken too little into account, even though it considerably affects the sound absorption capability of some walls.

In the frame of a doctoral thesis basic investigations into damping effects in the field of building acoustics have been carried out. Special interest is paid to the damping of a partition wall in a laboratory test facility. This damping directly affects sound insulation which is the most important quantity in building acoustics.

In accordance with the results of earlier examinations, investigations into damping effects in the field of building acoustics were applied to small downscaled models. These offer the advantage of the exact execution of construction and of freely selectable material properties and allow idealised constructions to be realised. Firstly, the necessary theoretical and experimental bases were provided for the design of the downscaled models.

Extensive investigations into material properties led to the parameters required for the experiments and simulations. Thereafter, the individual effects that lead to the damping of the partition wall were determined as loss factors by experiment. A simulation undertaken by means of statistical energy analysis (SEA) allowed detailed insight into the energies and power flows of the system in total to be gained. Both the experiment and the simulation showed in agreement that the power flowing from the facility into the partition cannot be neglected a priori as has been common up to now. Depending on the laboratory situation, effects which have been thought of as loss effects to date can be turned into gain effects for the partition.

Since the power flows are the basis for the treatment of loss factors which are the measurement quantities for the damping of a partition wall, the complexity of power flows requires a rethink. Previous conclusions and measurement procedures must be tested for validity. Particularly, the standard procedure for measuring the total loss factor, which is the main measurement quantity for damping in practise, was analysed by a transient SEA simulation. In agreement with model measurements, it could be shown that, due to the complex power flow in a wall test facility, the total loss factor is determined as much too low for typical standard situations.

The insights gained about the damping of a partition wall in a building acoustics test facility explain previous discrepancies but also raise some new questions of a basic nature. In future, more effort will be required in practise to determine the influence of damping. This thesis offers a starting point for that.

Imke Frischmuth | alfa
Further information:
http://www.ptb.de
http://www.ptb.de/en/org/1/nachrichten1/2008/fundamentals/damping.htm

More articles from Architecture and Construction:

nachricht Smart homes will “LISTEN” to your voice
17.01.2017 | EML European Media Laboratory GmbH

nachricht Designing Architecture with Solar Building Envelopes
16.01.2017 | Fraunhofer-Institut für Solare Energiesysteme ISE

All articles from Architecture and Construction >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>