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23 records – page 1 of 3.

An Enhanced Beam Model for Glued Laminated Structures that takes Moisture, Mechano-sorption and Time Effects into Account

https://research.thinkwood.com/en/permalink/catalogue44
Year of Publication
2014
Topic
Moisture
Serviceability
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Ormarsson, Sigurdur
Steinnes, Jan
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Moisture
Serviceability
Keywords
Climate
Creep
Finite Element Model
Hygro-Mechanical
Long-term
Visco-Elastic
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
There is a need of more advanced analysis for studying how the long-term behaviour of glued laminated timber structures is affected by creep and by cyclic variations in climate. A beam theory is presented able to simulate the overall hygro-mechanical and visco-elastic behaviour of (inhomogeneous) glulam structures. Two frame structures subjected to both mechanical and cyclic environmental loading are analysed to illustrate the advantages the model involved can provide. The results indicate clearly both the (discontinuous) inhomogeneity of the glulam products and the variable moisture-load action that occurs to have a significant effect on deformations, section forces and stress distributions within the frame structures that were studied
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Closed-form Solutions for Predicting the Thick Elastic Plate Behavior of CLT and Timber Panels with Gaps

https://research.thinkwood.com/en/permalink/catalogue1295
Year of Publication
2018
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Franzoni, Lorenzo
Lebée, Arthur
Lyon, Florent
Forêt, Gilles
Publisher
ScienceDirect
Year of Publication
2018
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Elastic Behavior
Gaps
Language
English
Research Status
Complete
Series
Engineering Structures
Summary
In a former paper by the authors [1], the elastic behavior of Cross Laminated Timber (CLT) and timber panels having periodic gaps between lateral lamellae has been analyzed. A thick plate homogenization scheme based on Finite Elements computations has been applied. The predicted behavior was in agreement with experimental results. In this paper, simplified closed-form solutions are derived in order to avoid FE modeling. Both cases of narrow gaps of CLT panels and wide gaps of innovative lightweight panels are investigated. CLT and timber panels with gaps are modeled as a space frame of beams connected with wooden blocks. The contribution of both beams and blocks to the panel’s mechanical response is taken into account, leading to closed-form expressions for predicting the panel’s stiffnesses and maximum longitudinal and rolling shear stresses. The derived closed-form solutions are in agreement with the reference FE results and they can be used for practical design purposes.
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Comparison of Bending Stiffness of Cross-Laminated Solid Timber Derived by Modal Analysis of Full Panels and by Bending Tests of Strip-Shaped Specimens

https://research.thinkwood.com/en/permalink/catalogue445
Year of Publication
2012
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Steiger, René
Gülzow, Arne
Czaderski, Christoph
Howald, Martin
Niemz, Peter
Publisher
Springer-Verlag
Year of Publication
2012
Country of Publication
Germany
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Elastic Properties
Stiffness Properties
Bending Test
Bending Stiffness
Panels
Language
English
Research Status
Complete
Series
European Journal of Wood and Wood Products
ISSN
1436-736X
Summary
The design of cross-laminated solid timber (CLT) as load-bearing plates is mainly governed by serviceability criterions like maximal deflection and susceptibility to vibration. Hence, predicting the respective behavior of such plates requires accurate information about their elastic properties. According to product standards, the bending stiffness of CLT has to be assessed from 4-point bending tests of strip-shaped specimens, cut from the CLT panels. By comparing elastic properties of CLT derived by means of modal analysis of full panels with the results of bending tests on 100 mm and 300 mm wide strip-shaped specimens it is shown, that by testing single 100 mm wide strip-shaped specimens bending stiffness of full panels cannot be assessed correctly, whereas single 300 mm wide strips or averages of 5 to 6 100 mm wide strip-shaped specimens lead to acceptable results. Hence, strip-shaped specimens should only be used in the course of factory quality control or when assessing the bending stiffness of parts of CLT panels used as beam-like load-bearing elements but not to derive bending stiffness of gross CLT panels. Verification by carrying out static bending tests of gross CLT panels under different loading situations showed that alternatively to tests on strip-shaped specimens or estimations with the compound theory, the overall stiffness properties of CLT can be derived directly by a modal analysis of full-size panels.
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A Contribution to the Design of Ribbed Plates

https://research.thinkwood.com/en/permalink/catalogue1692
Year of Publication
2016
Topic
Design and Systems
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Author
Augustin, Manfred
Zimmer, Severin
Bogensberger, Thomas
Sleik, Tim
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Topic
Design and Systems
Mechanical Properties
Keywords
Ribbed Plates
Elastic Model
Shear Stresses
Tensile Stresses
Notches
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4262-4271
Summary
The topic of this paper is the discussion of a proposal for the design of ribbed plates built-up with CLT (plate)- and GLT (ribs)- members. The suggested elastic model is based on the work of Abdelouahed [13] and Smith and Teng [14] for the strengthening of concrete members with FRP plates and will be applied for the mentioned loadcarrying timber elements. As a result so far it could be observed, that high peaks of shear and tensile stresses perpendicular to the interface (glue-line) occur due to the elastic consideration of the material. The model was evaluated by some pre-test which showed an acceptable correlation between the predictions of the model and a 2D-FEM analysis. It is evident, that the notches at the end of the rips must be reinforced by e.g. self-tapping screws or glued in rod to achieve effective solutions for this load carrying element. With the discussed model the shear and tensile stresses and forces resp. perpendicular to the interface can be computed.
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Elastic Behavior of Cross Laminated Timber and Timber Panels with Regular Gaps: Thick-Plate Modeling and Experimental Validation

https://research.thinkwood.com/en/permalink/catalogue1341
Year of Publication
2017
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Franzoni, Lorenzo
Lebée, Arthur
Lyon, Florent
Forêt, Gilles
Publisher
ScienceDirect
Year of Publication
2017
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Homogenization
Gaps
Elastic Behavior
Bending Stiffness
Thick Plates
Language
English
Research Status
Complete
Series
Engineering Structures
Summary
In the present paper, the influence of periodic gaps between lamellas of Cross Laminated Timber (CLT) on the panel’s elastic behavior is analyzed by means of a periodic homogenization scheme for thick plates having periodic geometry. Both small gaps, due to the fabrication process of not-gluing lateral lamellas, and wider gaps are investigated. The results obtained with the periodic homogenization scheme are compared to existing closed-form solutions and available experimental data. It appears that the plate bending stiffness can be well predicted with both homogenization and simplified methods, while only the homogenization approach is in agreement with the experimental in-plane and out-of-plane shear behavior. The influence of several properties of CLT lay-up on the mechanical response is pointed out as well.
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Elastic Constants of Cross Laminated Timber Panels of Industrial Size: Non-Destructive Measurement and Verification

https://research.thinkwood.com/en/permalink/catalogue1538
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Zhou, Jianhui
Chui, Ying Hei
Schickhofer, Gerhard
Frappier, Julie
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Elastic Constants
Modulus of Elasticity
Shear Modulus
Non-Destructive Tests
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 1061-1068
Summary
Cross laminated timber (CLT) is leading the evolution of wood construction throughout the world. As atwo-dimensional plate-like construction product, the in-plane elastic constants of CLT panels are the fundamental parameters for serviceability design. The elastic constants including moduli of elasticity (MOE) in major and minor strength direction ( and y) and in-plane shear modulus ( xy) of full-size CLT panels with different dimensions and layups from three CLT producers were measured by a non-destructive test (NDT) method developed by the first author. In total, 51 CLT panels were tested with most of the testing conducted at CLT mills. The measured values were used to examine the existing effective stiffness prediction models of CLT. Results show that k-method can be used for predicting and y values of industrial size CLT with a large length/ width to thickness ratio. xy cannot be well predicted by k-method and is greatly affected by edge bonding and gaps. Gamma method and shear analogy method can include the effect of transverse shear to different extents into account in predicting apparent or y. Shear analogy method appears to predict closer apparent to the measured values than gamma method for CLT with small length to thickness ratio. However, the effect of transverse shear on apparent y is not as much as predicted by shear analogy method for CLT panels with width from 1 to 3 meters. NDT by modal testing was proven to be an efficient mechanical property evaluation method for full-size CLT panels.
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Elastic Response of Cross Laminated Engineered Bamboo Panels Subjected to In-Plane Loading

https://research.thinkwood.com/en/permalink/catalogue1805
Year of Publication
2017
Topic
Mechanical Properties
Material
Other Materials
Author
Archila-Santos, Hector
Walker, Pete
Ansell, Martin
Rhead, Andrew
Lizarazo-Marriaga, Juan
Publisher
ICE Publishing
Year of Publication
2017
Country of Publication
United Kingdom
Format
Journal Article
Material
Other Materials
Topic
Mechanical Properties
Keywords
Compression
Deformation
Elastic Moduli
Bamboo
Panels
G-XLam
Language
English
Research Status
Complete
Series
Proceedings of the Institution of Civil Engineers - Construction Materials
ISSN
1747-650X
Online Access
Free
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Elevated Temperature Effects on the Shear Performance of a Cross-Laminated Timber (CLT) Wall-to-Floor Bracket Connection

https://research.thinkwood.com/en/permalink/catalogue2106
Year of Publication
2019
Topic
Fire
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls
Floors

Equivalent-frame Model for Elastic Behaviour of Cross-laminated Timber Walls with Openings

https://research.thinkwood.com/en/permalink/catalogue2417
Year of Publication
2020
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Mestar, Mohammed
Doudak, Ghasan
Caola, Maurizio
Casagrande, Daniele
Publisher
ICE Publishing
Year of Publication
2020
Country of Publication
Scotland
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Design and Systems
Keywords
Computational Mechanics
Structural Frameworks
Timber Structures
Elastic Behaviour
Language
English
Research Status
Complete
Series
Proceedings of the Institution of Civil Engineers - Structures and Buildings
Online Access
Free
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Feasibility of Predictive Assessment of Bending Performance of CLT Plates of Canadian Hemlock

https://research.thinkwood.com/en/permalink/catalogue2107
Year of Publication
2019
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls

23 records – page 1 of 3.