Comparison of multi-storey cross-laminated timber and timber frame buildings by in situ modal analysis

Abstract

The dynamic properties of two common structural systems for multi-storey timber buildings are compared through in-situ testing of completed buildings. The two five-storey buildings examined are identical except for their structural system, which in one is sheathed stud-and-rail timber construction, and in the other a cross-laminated timber panel system. Both also have a reinforced-concrete core located at the centre of one edge of the rectangular plan of each building. An output-only modal analysis method was used to identify the modal properties of the buildings: the random decrement technique was applied to the stochastic measured response, and then the time-domain random decrement signature was used for modal analysis by the Ibrahim Time Domain method. The natural frequencies, damping ratios and mode shapes of the first three vibration modes of the buildings were identified, and compared with those modeled based on the properties of the core and timber walls. The variations in properties between the two buildings are discussed. The two structures show very similar natural frequencies and damping ratios, suggesting that they could perhaps be considered as the same class of building in design for lateral movement.

Influence of laminate direction and glue area on in-plane shear modulus of cross-laminated timber

“…G is important for CLT walls if they are used as shear walls to resist lateral movements of buildings. Lateral (shear) stiffness is important, and it is necessary to have sufficient lateral stiffness, especially for tall wooden buildings [3]. Several parameters affect the shear stiffness in a CLT panel.…”

Lightweighting with Timber: An Opportunity for More Sustainable Urban Densification

“…However, there are a number of technical challenges associated with making best use of the potential afforded by lightweighting with timber and these provide many promising directions for future research. These research directions will include a need for better understanding of the dynamic effects that may begin to govern the design of lighter structures, such as acoustic (Rasmussen and Machimbarrena, 2014), wind-induced (Malo et al, 2016;Reynolds et al, 2016) or footfall induced vibrations (Weckendorf et al, 2016). This will provide opportunities for exploring the intelligent use of isolation, damping and active systems to control building behaviour rather than relying on the presence of mass.…”

Dynamic Characterization and Vibration Analysis of a Four-Story Mass Timber Building

“…The building, known as "Albina Yard, " is an example of a hybrid structure, exhibiting a mass timber gravity system, while its lateral force resisting system consists of light-frame shear walls. While extensive research has gone into characterizing the structural properties of mass timber members and subsystems, few research studies have analyzed the dynamic behavior of buildings encompassing mass timber structural products, and specifically CLT (Reynolds et al, 2014(Reynolds et al, , 2015(Reynolds et al, , 2016Hu et al, 2016). The limited number of currently built mass timber buildings, especially in North America, makes this endeavor more challenging, while it provides motivation for characterizing the as-built modal properties of this type of structures.…”