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8 records – page 1 of 1.

Damping in Timber Structures

https://research.thinkwood.com/en/permalink/catalogue106
Year of Publication
2012
Topic
Design and Systems
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Floors
Beams
Author
Labonnote, Nathalie
Organization
Norwegian University of Science and Technology
Year of Publication
2012
Country of Publication
Norway
Format
Thesis
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Floors
Beams
Topic
Design and Systems
Keywords
Damping
Model
Panels
Spruce
Testing
Vibrations
Language
English
Research Status
Complete
Summary
Key point to development of environmentally friendly timber structures, appropriate to urban ways of living, is the development of high-rise timber buildings. Comfort properties are nowadays one of the main limitations to tall timber buildings, and an enhanced knowledge on damping phenomena is therefore required, as well as improved prediction models for damping. The aim of this work has consequently been to estimate various damping quantities in timber structures. In particular, models have been derived for predicting material damping in timber members, beams or panels, or in more complex timber structures, such as floors. Material damping is defined as damping due to intrinsic material properties, and used to be referred to as internal friction. In addition, structural damping, defined as damping due to connections and friction in-between members, has been estimated for timber floors.
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Designing Pedestrian Stress-Laminated Timber Bridges for Multiple Spans: Parameters Related to Dynamic Response

https://research.thinkwood.com/en/permalink/catalogue2576
Year of Publication
2019
Topic
Design and Systems
Application
Bridges and Spans

Dynamic Performance of Timber and Timber-Concrete Composite Flooring Systems

https://research.thinkwood.com/en/permalink/catalogue229
Year of Publication
2013
Topic
Connections
Serviceability
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Author
Rijal, Rajendra
Organization
University of Technology Sydney
Year of Publication
2013
Country of Publication
Australia
Format
Thesis
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Topic
Connections
Serviceability
Keywords
Connections
Costs
Fasteners
Finite Element Model
Long Span
Multi-Storey
Sustainability
Vibrations
Small Scale
Static Load Tests
Damage Index (DI) Method
Loss of Composite Action Index (LCAI)
Language
English
Research Status
Complete
Summary
The work presented in this thesis deals with the investigation of the dynamic performance of timber only and TCC flooring systems, which is one of the sub-objectives of the research focus at UTS. In particular, the presented research assesses the dynamic performance of long-span timber and TCC flooring systems using different experimental und numerical test structures. For the experimental investigations, experimental modal testing and analysis is executed to determine the modal parameters (natural frequencies, damping ratios and mode shapes) of various flooring systems. For the numerical investigations, finite element models are calibrated against experimental results, and are utilised for parametric studies for flooring systems of different sizes. Span tables are generated for both timber and TCC flooring systems that can be used in the design of long-span flooring systems to satisfy the serviceability fundamental frequency requirement of 8 Hz or above. To predict the fundamental frequency of various TCC beams and timber floor modules (beams), five different analytical models are utilised and investigated. To predict the cross-sectional characteristics of TCC systems and to identify the effective flexural stiffness of partially composite beams, the “Gamma method” is utilised. [...] two novel methods are developed in this thesis that determines the degree of composite action of timber composite flooring systems using only measurements from non-destructive dynamic testing. The core of both methods is the use of an existing mode-shape-based damage detection technique, namely, the Damage Index (DI) method to derive the loss of composite action indices (LCAIs) named as LCAI1 and LCAI2. The DI method utilises modal strain energies derived from mode shape measurements of a flooring system before and after failure of shear connectors. The proposed methods are tested and validated on a numerical and experimental timber composite beam structure consisting of two LVL components (flange and web). To create different degrees of composite action, the beam is tested with different numbers of shear connectors to simulate the failure of connection screws. The results acquired from the proposed dynamic-based method are calibrated to make them comparable to traditional static-based composite action results. It is shown that the two proposed methods can successfully be used for timber composite structures to determine the composite action using only mode shapes measurements from dynamic testing.
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Efficient Measurement of Elastic Constants of Cross Laminated Timber using Modal Testing

https://research.thinkwood.com/en/permalink/catalogue117
Year of Publication
2014
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Author
Zhou, Jianhui
Chui, Ying Hei
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Acoustics and Vibration
Keywords
Elasticity
Modal Testing
Modulus of Elasticity
Natural Frequency
Testing
Vibrations
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
It has been shown that measurement of elastic constants of orthotropic wood-based panel products can be more efficiently measured by modal testing technique. Identification of vibration modes and corresponding natural frequencies is key to the application of modal testing technique. This process is generally tedious and requires a number of measurement locations for mode shape identification. In this study, a simplified method for frequency identification was developed which will facilitate the adoption of the vibration-based testing technique for laboratory and industrial application. In the method, the relationship between frequency order and mode order is first studied considering the boundary condition, elastic properties of the orthotropic panel. An algorithm is proposed to predict the frequency values and mode indices based on corresponding normalized sensitivity to elastic constants, initial estimates of orthotropic ratios and measured fundamental natural frequency. The output from the algorithm can be used for identification of sensitive natural frequencies from up to three frequency spectra. Then the algorithm is integrated with the elastic calculation algorithm to extract the elastic constants from the sensitive frequencies. The elastic constants of cross laminated timber panels were measured by the proposed method. The moduli of elasticity agree well with static testing results. The calculated in-plane shear modulus was found to be within the expected range.
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Experimental Evaluations of Material Damping in Timber Beams of Structural Dimensions

https://research.thinkwood.com/en/permalink/catalogue574
Year of Publication
2013
Topic
Acoustics and Vibration
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Author
Labonnote, Nathalie
Rønnquist, Anders
Arne Malo, Kjell
Publisher
Springer Berlin Heidelberg
Year of Publication
2013
Country of Publication
Germany
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Topic
Acoustics and Vibration
Keywords
Damping
Flexural Vibrations
Language
English
Research Status
Complete
Series
Wood Science and Technology
Summary
Understanding the inherent damping mechanisms of floor vibrations has become a matter of increasing importance following the development of new composite floor layouts and increased span. The present study focuses on the evaluation of material damping in timber beam specimens with dimensions that are typical of common timber floor structures. Using the impact test method, 11 solid wood beams and 11 glulam beams made out of Norway Spruce (Picea abies) were subjected to flexural vibrations. The tests involved different spans and orientations. A total of 420 material damping evaluations were performed, and the results are presented as mean values for each configuration along with important statistical indicators to quantify their reliability. The consistency of the experimental method was validated with respect to repeatability and reproducibility. General trends found an increasing damping ratio for higher modes, shorter spans, and edgewise orientations. It is concluded from the results that material damping of timber beams of structural dimensions is governed by shear deformation, which can be expressed more conveniently with respect to the specific mode shape and its derivatives.
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Guidelines Definition for In-Situ Vibration Measurements of Buildings

https://research.thinkwood.com/en/permalink/catalogue1980
Year of Publication
2018
Topic
Acoustics and Vibration
Material
Timber-Concrete Composite
Application
Floors

Vibration Serviceability Design Analysis of Cross-Laminated Timber Floor Systems

https://research.thinkwood.com/en/permalink/catalogue40
Year of Publication
2014
Topic
Acoustics and Vibration
Serviceability
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Ussher, Ebenezer
Sadeghi, Masoud
Weckendorf, Jan
Smith, Ian
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Acoustics and Vibration
Serviceability
Keywords
Finite Element Model
Floors
Vibrations
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Vibration serviceability of various types of timber floor systems has claimed much attention during past decades. Yet the definition of robustly reliable engineering design approaches has remained elusive, except in well-defined situations. Successful de...
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8 records – page 1 of 1.