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Dynamic Behaviour of LVL-Concrete Composite Flooring Systems

https://research.thinkwood.com/en/permalink/catalogue315
Year of Publication
2015
Topic
Acoustics and Vibration
Serviceability
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Author
Abd. Ghafar, Nor
Organization
University of Canterbury
Year of Publication
2015
Country of Publication
New Zealand
Format
Thesis
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Topic
Acoustics and Vibration
Serviceability
Keywords
Finite Element Model
Dynamic Behaviour
Natural Frequency
Mode shape
Electrodynamic Shaker
Boundary Conditions
Language
English
Research Status
Complete
Summary
This research focuses on the dynamic behaviour of long span LCC flooring systems. Experimental testing and finite element modelling was used to determine the dynamic behaviour, with particular regard to the natural frequency, fn and mode shape of an LCC floor. Both the experimental results and the finite element analyses agreed and showed that increased stiffness increased the natural frequency of the floor, and the boundary conditions influenced the dynamic behaviour of the LCC floor. Providing more restraint increased the stiffness of the floor system. The connectors' stiffness did not influence the dynamic performance of the floor. The research showed that a 8 m LCC long span floor can be constructed using LVL joists of between 300 mm to 400 mm depth with a concrete thickness of 65 mm for the longer spans, and joists of between 150 mm to 240 mm depth in conjunction with a concrete topping thickness of 100 mm for the shorter spans.
Online Access
Free
Resource Link
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Vibration Properties of a Timber Floor Assessed in Laboratory and During Construction

https://research.thinkwood.com/en/permalink/catalogue488
Year of Publication
2015
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Jarnerö, Kirsi
Brandt, Anders
Olsson, Anders
Publisher
ScienceDirect
Year of Publication
2015
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Acoustics and Vibration
Keywords
Damping Ratios
Eurocode
Mode shape
Natural Frequency
Prefabrication
Boundary Conditions
Language
English
Research Status
Complete
Series
Engineering Structures
Summary
In the present work the change in natural frequencies, damping and mode shapes of a prefabricated timber floor element have been investigated when it was integrated into a building structure. The timber floor element was first subjected to modal testing in laboratory with ungrounded and simply supported boundary conditions, and then in situ at different stages of building construction. The first five natural frequencies, damping ratios and mode shapes of the floor element and the entire floor were extracted and analysed. It may be concluded that the major change in natural frequencies occur as the floor element is coupled to the adjacent elements and when partitions are built in the studied room, the largest effect is on those modes of vibration that largely are constrained in their movement. The in situ conditions have a great influence on the damping, which depends on the damping characteristics of the supports, but also on the fact that the floor is integrated into the building and interacts with it. There is a slight increase of damping in the floor over the different construction stages and the damping values seem to decrease with ascending mode order.
Online Access
Free
Resource Link
Less detail