Dynamic Response of Tall Timber Buildings under Service Load
Coordinator: Marie Johansson, RISE Research Institutes of Sweden, Sweden
marie.johansson (at) ri.se
Other partners: FR, NO, SE, SI, UK
Project duration: 03/2019-10/2022
The aim of the DynaTTB project was to quantify the structural damping in as-built tall timber buildings (TTB). This included develop bottom-up numerical finite element models for estimating the dynamic response of multi-storey timber buildings, validate the predicted response with in-situ measurements on TTBs and disseminate findings via a TTB Design Guideline for design practitioners.
During the project time the dynamic properties (acceleration, resonance frequency, modes shape, damping and modal mass) have been evaluated through forced vibration tests (FVT) on eight multi-storey and tall timber buildings around Europe (UK, Sweden, Norway, France, Slovenia), including the tallest timber building in the World, an 85-meter tall Mjøstårnet in Brumunddal, Norway.
FE models have then been used to simulate the behaviour of the building under wind loads in serviceable limit states. The adaptation has been partly based on the measurements made on the entire buildings. Different variants of stiffness, mass and damping have been used to obtain good agreement between calculation models and measured dynamic properties. The calculation models provide reliable results regarding natural frequency and mode shape for the three to six lowest resonance frequencies. This can be seen as very good results for calculation models for dynamic properties of systems as complex as these tall timber buildings.
The project’s results will be summarized in a Best Practice for measuring and modelling tall timber buildings subjected to wind loads in serviceability limit state.