Forced Response Measurements on a Seven Storey Timber Building in Sweden

Abstract

Forced vibration tests have been conducted on the seven-storey timber building Eken in Mariestad in Sweden. The main objective is to estimate the building's dynamic properties from test data. The eigenfrequencies, mode shapes and their scaling are useful to calibrate numerical models. However, the most important outcomes are the estimates of the modal damping values. The reason is that the damping impacts the acceleration, and thus the serviceability of the building, and at the same time, it is very hard to model damping. So, during the design phase, one must rely on previous test data (of which very few exist for taller timber buildings) or rule of thumbs. It is therefore important to gain knowledge about the damping for timber buildings in order to enable good designs of future and taller timber buildings. The test data shows that the modal damping is roughly equal to 2% of the critical viscous ones for the eigenmodes extracted. The test campaign on Eken is made as a part of the project Dyna-TTB in which vibrational tests have been performed on eight high-rise timber buildings, in Europe, of which Eken is one.

Dynamic Response of Tall Timber Buildings Under Service Load - Results From the Dynattb Research Program

“…Limtre, rune.abrahamsen@moelven.no, 2 Sweco, magne.bjertnaes@sweco.no, petter.navik@sweco.no, 3 Eiffage, jacques.bouillot@eiffage.com, ludwig.hahusseau@eiffage.com, 4 University of Ljubljana, Bostjan.Brank@ikpir.fgg.uni-lj.si, bkurent@fgg.uni-lj.si, 5 Moelven SE, crocetti@kth.se, thomas.johansson@moelven.se, 6 CSTB, olivier.flamand@cstb.fr, alan.jalil@cstb.fr, manuel.manthey@cstb.fr, 7 Arbonis, fgarains@arbonis.com, 8 InnoRenew CoE, gavric.igor@gmail.com, iztok.sustersic@innorenew.eu, 9 RISE, marie.johansson@ri.se, pierre.landel@ri.se, 10 Uni Exeter, wka203@exeter.ac.uk, A.Pavic@exeter.ac.uk 11 LNU, andreas.linderholt@lnu.se, 12 NTNU, kjell.malo@ntnu.no, anders.ronnquist@ntnu.no, saule.tulebekova@ntnu.no 13 Smith&Wallwork, fernando.perez@ibk.baug.ethz.ch are sensitive to wind loads in the serviceability limit state. The building height where sway is necessary to consider in the design of the structural system is lower than for other building materials such as steel or concrete.…”

“…This paper presents an overview of the results and the main structure of the guidelines. More detailed results can be found in [3]- [6] which will be presented at the WCTE 2023 conference. Other results can be found in for example [7]- [15].…”

“…A preliminary evaluation showed that the relative viscous damping was 1.6% for the first bending mode in the weak direction. More details of the measurements can be found in [3].…”