Skip header and navigation

4 records – page 1 of 1.

Correlation between Sound Insulation and Occupants’ Perception – Proposal of Alternative Single Number Rating of Impact Sound

https://research.thinkwood.com/en/permalink/catalogue79
Year of Publication
2014
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Ljunggren, Fredrik
Simmons, Christian
Hagberg, Klas
Publisher
ScienceDirect
Year of Publication
2014
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Acoustics and Vibration
Keywords
Airborne Sound
Frequency
Insulation
Lightweight
Sound
Sweden
Language
English
Research Status
Complete
Series
Applied Acoustics
Summary
Traditionally, multi-family houses have been constructed using heavy, homogenous materials like concrete and masonry. But as a consequence of the progress of lightweight building systems during the last decades, it has been questioned whether standardized sound insulation evaluation methods still are appropriate. An extensive measurement template has been applied in a field survey where several vibrational and acoustical parameters were determined in ten Swedish buildings of various constructions. In the same buildings, the occupants were asked to rate the perceived annoyance from a variety of natural sound sources. The highest annoyance score concerned impact sounds, mainly in the buildings with lightweight floors. Statistical analyses between the measured parameters and the subjective ratings revealed a useful correlation between the rated airborne sound insulation and R0 w þ C50—3150 while the correlation between the rated impact sound insulation and L0 n;w þ CI;50—2500 was weak. The latter correlation was considerably improved when the spectrum adaptation term with an extended frequency range starting from 20 Hz was applied. This suggests that frequencies below 50 Hz should be considered when evaluating impact sound in lightweight buildings.
Online Access
Free
Resource Link
Less detail

Finite Element Modeling for Vibration Transmission in a Cross Laminated Timber Structure

https://research.thinkwood.com/en/permalink/catalogue1633
Year of Publication
2016
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Vardaxis, Nikolaos-Georgios
Hagberg, Klas
Bard, Delphine
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Keywords
Sweden
Numerical Model
Finite Element Model
Impact Noise Transmission
Impact Sound
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2953-2962
Summary
This paper deals with a certain type of C.L.T. (Cross Laminated Timber) construction, in a residential building in Fristad, Sweden. The objective is to study impact noise transmission, at the lower frequency range (10-200 Hz), where wooden dwellings perform inefficiently, in terms of acoustic quality. The vibrational behavior of lightweight structures and specifically a multilayered floor separating two vertically adjacent bedrooms are investigated. A numerical model of the multilayered test plate, which includes sound insulation and vibration isolation layers, is developed using the Finite Element Method (F.E.M.) in commercial software. The design process, the analysis and improvement of the calculated outcome concerning accuracy and complexity are of interest. In situ vibration measurements were also performed so as to evaluate the structures dynamic behavior in reality and consequently the validity of the modelled results. The whole process from design to evaluation is discussed thoroughly, where uncertainties of the complex F.E.M. model and the approximations of the real structure are analyzed. Numerical comparisons are presented including mechanical mobility and impact noise transmission results. The overall aim is to set up a template of calculations that can be used as a prediction tool in the future by the industry and researchers.
Online Access
Free
Resource Link
Less detail

Modelling Prerequisites – FEM/SEA Impact and Airborne Sound

https://research.thinkwood.com/en/permalink/catalogue840
Year of Publication
2017
Topic
Acoustics and Vibration
Material
Light Frame (Lumber+Panels)
Application
Wood Building Systems
Floors
Walls
Author
Bard, Delphine
Negreira, Juan
Guigou-Carter, Catherine
Borello, Gerard
Kouyoumji, Jean-Luc
Speranza, Alice
Coguenanff, Corentin
Hagberg, Klas
Organization
Silent Timber Build
Year of Publication
2017
Country of Publication
Sweden
Format
Report
Material
Light Frame (Lumber+Panels)
Application
Wood Building Systems
Floors
Walls
Topic
Acoustics and Vibration
Keywords
Europe
Finite Element Model
Frequencies
SEA Model
Prediction
Impact Sound Insulation
Airborne Sound Insulation
Language
English
Research Status
Complete
Summary
This report comprises reslts from the work done within work package 1 in the WWN+ project "Silent Timber Build", WP 1: Prediction tools, low and high frequencies. The aim from this WP was to develop prediction tools applied for wooden constructions. Included in this is also to create necessary basis for enough accuracy for any European wood construction. It implies development of new methods but also to understand how input forces primarily from the tapping machine affects the resuts of impact sound levels. The WP also describes how models are developed, in order to provide expected accuracy and then how to further improve the models in order to optimize floor and wall assemblies. The Work Package has been closely linked to WP 2 but also WP3. Using the reults from WP 2, the prediction model results can be compared to expected values for any European construction. From that optimization of floor assemblies and refining of the model is possible.
Online Access
Free
Resource Link
Less detail

Validation of Prediction Tools and Constructions – Grouping, Verification Measurements and Trend Analysis

https://research.thinkwood.com/en/permalink/catalogue841
Year of Publication
2017
Topic
Design and Systems
Connections
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Timber-Concrete Composite
Application
Floors
Author
Homb, Anders
Guigou-Carter, Catherine
Hagberg, Klas
Späh, Moritz
Ferk, Heinz
Organization
Silent Timber Build
Year of Publication
2017
Country of Publication
Sweden
Format
Report
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Timber-Concrete Composite
Application
Floors
Topic
Design and Systems
Connections
Acoustics and Vibration
Keywords
Europe
Impact Sound Insulation
SEA
FEM
Language
English
Research Status
Complete
Summary
The report includes an overview of different floor assemblies used all over Europe. They have been selected and evaluated carefully and from that the floor assemblies are divided into different groups in order to fit to limit the number of possible setups. Hence the grouping is made in a manner that will facilitate modelling of floor assemblies using the different methods as developed within this project, Silent Timber Build. It can also be used in order to recommend different floor assemblies for different buildings and usage. The software that has been used and further developed within this project is a French software adapted to wooden building floor and wall components, “SEA Wood". In addition FEM software is used in order to improve and verify the results particularly in the low frequencies, which is of particular interest for structural solutions in wood.
Online Access
Free
Resource Link
Less detail