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Analysis of the Characteristics of External Walls of Wooden Prefab Cross Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue2694
Year of Publication
2020
Topic
Energy Performance
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Švajlenka, Jozef
Kozlovská, Mária
Badida, Miroslav
Moravec, Marek
Dzuro, Tibor
Vranay, František
Publisher
MDPI
Year of Publication
2020
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Energy Performance
Acoustics and Vibration
Keywords
Acoustic Properties
Thermal Properties
Prefabrication
Language
English
Research Status
Complete
Series
Energies
Summary
A balanced combination of heat flows creates suitable conditions for thermal comfort—a factor contributing to the quality of the internal environment of buildings. The presented analysis of selected thermal-technical parameters is up-to-date and suitable for verifying the parameters of building constructions. The research also applied a methodology for examining the acoustic parameters of structural parts of buildings in laboratory conditions. In this research, selected variant solutions of perimeter walls based on prefab cross laminated timber were investigated in terms of acoustic and thermal-technical properties. The variants structures were investigated in laboratory but also in model conditions. The results of the analyses show significant differences between the theoretical or declared parameters and the values measured in laboratory conditions. The deviations of experimental measurements from the calculated or declared parameters were not as significant for variant B as they were for variant A. These findings show that for these analyzed sandwich structures based on wood, it is not always possible to reliably declare calculated values of thermal-technical and acoustic parameters. It is necessary to thoroughly examine such design variants, which would contribute to the knowledge in this field of research of construction systems based on wood.
Online Access
Free
Resource Link
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Effect of Flexible Supports on Vibration Performance of Timber Floors

https://research.thinkwood.com/en/permalink/catalogue190
Year of Publication
2012
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Floors
Author
Jarnerö, Kirsi
Bolmsvik, Åsa
Brandt, Anders
Olsson, Anders
Organization
Euronoise
Year of Publication
2012
Country of Publication
Czech Republic
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Floors
Topic
Acoustics and Vibration
Keywords
Residential
Multi-Storey
Noise
Prefabrication
In Situ
Vibration
Damping
Interlayer
Language
English
Conference
Ninth European Conference on Noise Control (Euronoise)
Research Status
Complete
Notes
June 10-13, 2012, Prague, Czech Republic
Summary
In residential multi-storey buildings of timber it is of great importance to reduce the flanking transmission of noise. Some building systems do this by installing a vibration-damping elastic interlayer, Sylomer or Sylodyn , in the junction between the support and the floor structure. This interlayer also improves the floor vibration performance by adding damping to the structure. In the present work the vibration performance of a floor with such interlayers has been investigated both in laboratory and field tests. A prefabricated timber floor element was tested in laboratory on rigid supports and on supports with four different types of interlayers. The results are compared with in situ tests on a copy of the same floor element. The effect on vibration performance i.e. frequencies, damping ratio and mode shapes is studied. A comparison of the in situ test and the test with elastic interlayer in laboratory shows that the damping in situ is approximately three times higher than on a single floor element in the lab. This indicates that the damping in situ is affected be the surrounding building structure. The achieved damping ratio is highly dependent on the mode shapes. Mode shapes that have high mode shape coefficients along the edges where the interlayer material is located, result in higher modal damping ratios. The impulse velocity response, that is used to evaluate the vibration performance and rate experienced annoyance in the design of wooden joist floors, seems to be reduced when adding elastic layers at the supports.
Online Access
Free
Resource Link
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In Situ Measured Flanking Transmission in Light Weight Timber Houses with Elastic Flanking Isolators

https://research.thinkwood.com/en/permalink/catalogue231
Year of Publication
2013
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Floors
Wood Building Systems
Author
Ågren, Anders
Ljunggren, Fredrik
Organization
Inter-noise
Year of Publication
2013
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Floors
Wood Building Systems
Topic
Acoustics and Vibration
Keywords
Modules
Prefabrication
Sound Insulation
Elastomer Isolators
Language
English
Conference
Inter-noise 2013
Research Status
Complete
Notes
September 15-18, 2013, Innsbruck, Austria
Summary
There is a strong trend to industrially produce multi-storey light weight timber based houses. This concept allows the buildings to be manufactured to a more or less prefabricated extent. Most common types are volume/room modules or flat wall and floor modules. When assembling the modules at the building site, elastomer isolators are used in several constructions to reduce flanking transmission. The sound insulation demands in the Nordic countries are relatively high and therefore the flanking transmission must be well controlled, where elastomer isolators are an alternative. Decoupled radiation isolated walls is another. There are though no working studies or mathematical models of the performance of these isolators. They are only treated as simple mass-springs systems that operate vertically, i.e. one degree of freedom. In this paper there is an analysis of experimentally data of the structure borne sound isolating performance of elastomer isolators that are separating an excited floor from receiving walls. The performance dependence of structure type is also presented. An empirically based regression model of the vibration level difference is derived. The model is based on measurements of six elastomer field installations, which are compared to five comparable installations without elastomers. A goal is that the model can be used for input in future SEN prediction models for modeling of sound insulation.
Online Access
Free
Resource Link
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Vibration Properties of a Timber Floor Assessed in Laboratory and During Construction

https://research.thinkwood.com/en/permalink/catalogue488
Year of Publication
2015
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Jarnerö, Kirsi
Brandt, Anders
Olsson, Anders
Publisher
ScienceDirect
Year of Publication
2015
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Acoustics and Vibration
Keywords
Damping Ratios
Eurocode
Mode shape
Natural Frequency
Prefabrication
Boundary Conditions
Language
English
Research Status
Complete
Series
Engineering Structures
Summary
In the present work the change in natural frequencies, damping and mode shapes of a prefabricated timber floor element have been investigated when it was integrated into a building structure. The timber floor element was first subjected to modal testing in laboratory with ungrounded and simply supported boundary conditions, and then in situ at different stages of building construction. The first five natural frequencies, damping ratios and mode shapes of the floor element and the entire floor were extracted and analysed. It may be concluded that the major change in natural frequencies occur as the floor element is coupled to the adjacent elements and when partitions are built in the studied room, the largest effect is on those modes of vibration that largely are constrained in their movement. The in situ conditions have a great influence on the damping, which depends on the damping characteristics of the supports, but also on the fact that the floor is integrated into the building and interacts with it. There is a slight increase of damping in the floor over the different construction stages and the damping values seem to decrease with ascending mode order.
Online Access
Free
Resource Link
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