Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • 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
Numerical and experimental dynamic analyses of Hägernäs pedestrian bridge: Including seasonal effects
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
2019 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

Wood as a construction material has in recent years increased, in particular concerningpedestrian bridges. By utilizing wood, the ecological footprint can be reduced,and the material can be designed to comply with the increasing aesthetic demandbridge designers are facing. However, as the material weighs little with respect toits bearing capacity, combined with design becoming more slender, human inducedvibrations are becoming a problem.Having this in mind, the objective of the thesis is to conduct a case study on anexisting timber pedestrian bridge and assess its dynamic parameters by means ofexperiential testing and numerical modelling. The case study concerns the Hägernäsbridge, an arch bridge located in Hägernäs, Täby. The thesis also considers seasonaleffects by conducting experiments on two separate occasions. In addition, the thesisevaluates influencing parameters on the dynamic behaviour by conducting a sensitivityanalysis. To aid the above mentioned objective, a literature review coveringsimilar type of analysis is conducted. The literature review also studies the seasonaleffect, mainly from the asphalt layer, as its stiffness contribution is temperaturedependant.The results from the dynamic parameters showed that not all modes fall above therecommended values concerning damping ratio (with values above 1-1.5%). However,all modes fulfill design criteria concerning the magnitude of the natural frequencies.Furthermore, results showed that the natural frequencies are highly temperaturedependant. The measured values during warm weather (+17C) resulted in lowervalues than those from the cold weather experiment (-10C). Moreover, the greatestdifference, by 21% was on the 1st transverse mode and the lower difference was onthe 1st vertical mode, that decreased by merely 5%. Moreover, the damping ratiowas calculated and it was not possible to find any correlation between warm andcold temperature. Instead, decreased temperature caused some modes to increase indamping ratio and others to decrease. The most affected mode was once again the1st transverse mode which increased by 146% going from warm to cold temperature

Place, publisher, year, edition, pages
2019.
Series
TRITA-ABE-MBT ; 19473
Keywords [en]
Pedestrian Timber Arch Bridge, Seasonal Effect, Modal Analysis, Dynamic Analysis, Finite Element Method, Experiments vi
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:kth:diva-254550OAI: oai:DiVA.org:kth-254550DiVA, id: diva2:1333532
Available from: 2019-07-01 Created: 2019-07-01

Open Access in DiVA

fulltext(28323 kB)42 downloads
File information
File name FULLTEXT01.pdfFile size 28323 kBChecksum SHA-512
8d6263b98b62e23ba6ff341561d8fd82fccaca93de70b25fa1c342fcf95c931665b9ba4686a485dae32b66331a749b11a57ce664ff52151f2b2838a8f18db1ab
Type fulltextMimetype application/pdf

By organisation
Structural Engineering and Bridges
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
Total: 42 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 121 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • 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