lnu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Impact evaluation of a thin hybrid wood based joist floor
SP Technical Research Institute.ORCID iD: 0000-0002-0019-4568
Linnaeus University, Faculty of Technology, Department of Mechanical Engineering. (Maskinteknik)ORCID iD: 0000-0002-4404-5708
Linnaeus University, Faculty of Technology, Department of Mathematics.
2016 (English)In: Proceedings of ISMA 2016, presented at the International Conference on Noise andVibration Engineering (ISMA) / [ed] Sas, P; Moens, D; VanDeWalle, A, Leuven, Belgium: Katholieke University Leuven , 2016, 589-602 p.Conference paper, Published paper (Refereed)
Abstract [en]

The purpose of this paper is twofold. The first aim is to develop a numericalanalysis procedure, by combining FRFs from FE-models with analyticalformulas for sound emission and transmission from the ceiling anddownwards within a room with four walls. The aim is to, by applying thisapproach; accomplish a tool which calculates the relative impact soundbetween different joist floors, in the low frequency range. The second aim is tobenchmark a thin hybrid wooden based joist floor with similar thickness,surface weight and global bending stiffness as a concrete hollow core floorstructure. What will be the difference in sound transmission? The question isrelevant since it may be necessary to make thinner wood based joist floors inhigh rise buildings, if wood should stay competitive against concrete. Theresults show that the direct transmissions of impact sound are very similararound the first bending mode. As the frequency increases, the modes in thestructures differ significantly. Below 100 Hz, the concrete floor has 4 modes,while the hybrid joist floor has 9 modes. As the frequency increases the soundradiation characteristics differs. The results show that it is possible to havesimilar sound transmission properties around the first bending modes for ahybrid based joist floor and a hollow core concrete floor structure with similar thicknesses. At the first modes of the structure, the information about thesurface weight and global bending stiffness are useful for prediction of soundtransmission properties but for higher modes, they are not sufficient.

Place, publisher, year, edition, pages
Leuven, Belgium: Katholieke University Leuven , 2016. 589-602 p.
National Category
Construction Management
Research subject
Technology (byts ev till Engineering), Civil engineering
Identifiers
URN: urn:nbn:se:lnu:diva-58129ISI: 000392486301010ISBN: 978-90-73802-94-0 (print)OAI: oai:DiVA.org:lnu-58129DiVA: diva2:1046772
Conference
The International Conference on Noise and Vibration Engineering (ISMA) in Leuven, Belgium 19-21 September 2016.
Available from: 2016-11-15 Created: 2016-11-14 Last updated: 2017-03-08Bibliographically approved
In thesis
1. Low Frequency Impact Sound in Timber Buildings: Simulations and Measurements
Open this publication in new window or tab >>Low Frequency Impact Sound in Timber Buildings: Simulations and Measurements
2016 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

An increased share of construction with timber is one possible way of achieving more sustainable and energy-efficient life cycles of buildings. The main reason is that wood is a renewable material and buildings require a large amount of resources. Timber buildings taller than two storeys were prohibited in Europe until the 1990s due to fire regulations. In 1994, this prohibition was removed in Sweden.

    Some of the early multi-storey timber buildings were associated with more complaints due to impact sound than concrete buildings with the same measured impact sound class rating. Research in later years has shown that the frequency range used for rating has not been sufficiently low in order to include all the sound characteristics that are important for subjective perception of impact sound in light weight timber buildings. The AkuLite project showed that the frequency range has to be extended down to 20 Hz in order to give a good quality of the rating. This low frequency range of interest requires a need for knowledge of the sound field distribution, how to best measure the sound, how to predict the sound transmission levels and how to correlate numerical predictions with measurements.

    Here, the goal is to improve the knowledge and methodology concerning measurements and predictions of low frequency impact sound in light weight timber buildings. Impact sound fields are determined by grid measurements in rooms within timber buildings with different designs of their joist floors. The measurements are used to increase the understanding of impact sound and to benchmark different field measurement methods. By estimating transfer functions, from impact forces to vibrations and then sound pressures in receiving rooms, from vibrational test data, improved possibilities to correlate the experimental results to numerical simulations are achieved. A number of excitation devices are compared experimentally to evaluate different characteristics of the test data achieved. Further, comparisons between a timber based hybrid joist floor and a modern concrete floor are made using FE-models to evaluate how stiffness and surface mass parameters affect the impact sound transfer and the radiation.

    The measurements of sound fields show that light weight timber floors in small rooms tend to have their highest sound levels in the low frequency region, where the modes are well separated, and that the highest levels even can occur below the frequency of the first room mode of the air. In rooms with excitation from the floor above, the highest levels tend to occur at the floor levels and in the floor corners, if the excitation is made in the middle of the room above. Due to nonlinearities, the excitation levels may affect the transfer function in low frequencies which was shown in an experimental study. Surface mass and bending stiffness of floor systems are shown, by simulations, to be important for the amount of sound radiated.

    By applying a transfer function methodology, measuring the excitation forces as well as the responses, improvements of correlation analyses between measurements and simulations can be achieved

Place, publisher, year, edition, pages
Linnaeus University, 2016. 100 p.
Series
Faculty of Technology, Report, 46
Keyword
Low-frequency, impact sound, light weight floor, timber joist floor, tapping machine, multi-storey timber building, frequency response functions., Stegljud
National Category
Other Civil Engineering Fluid Mechanics and Acoustics
Research subject
Technology (byts ev till Engineering), Civil engineering
Identifiers
urn:nbn:se:lnu:diva-58068 (URN)978-91-88357-46-5 (ISBN)
Presentation
2016-11-30, Sal Tegner, Linnéuniversitet, hus H, Växjö, 10:00 (English)
Opponent
Supervisors
Projects
ProWoodSilent Timber BuildUrban TranquilityBioInnovation FBBB
Funder
Knowledge Foundation
Available from: 2016-11-15 Created: 2016-11-10 Last updated: 2017-09-01Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Olsson, JörgenLinderholt, AndreasNilsson, Börje
By organisation
Department of Mechanical EngineeringDepartment of Mathematics
Construction Management

Search outside of DiVA

GoogleGoogle Scholar

Total: 215 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf