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7 records – page 1 of 1.

Advanced Modelling of Cross Laminated Timber (CLT) Panels in Bending

https://research.thinkwood.com/en/permalink/catalogue1796
Year of Publication
2015
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Franzoni, Lorenzo
Lebée, Arthur
Lyon, Florent
Forêt, Gilles
Publisher
HAL archives-ouvertes.fr
Year of Publication
2015
Country of Publication
Germany
Format
Presentation
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Mechanical Properties
Keywords
Bending
Model
Panels
Shear
Stiffness
Failure Behavior
Shear Force
Reference Test
Language
English
Conference
Euromech Colloquim 556 Theoretical Numerical and Experimental Analyses of Wood Mechanics
Research Status
Complete
Notes
May 2015, Dresde, Germany
Online Access
Free
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Bending Behavior of Regularly Spaced CLT Panels

https://research.thinkwood.com/en/permalink/catalogue1616
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Franzoni, Lorenzo
Lebée, Arthur
Lyon, Florent
Forêt, Gilles
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
FEM
Bending Stiffness
Shear Stiffness
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2368-2376
Summary
A regular alternation of lamellas and voids filled by insulating material within each layer of CLT can lead to cellular panels with improved acoustical, thermal and fire performance. In order to support the development of these innovative and lighter engineered wood products, their mechanical behavior is investigated in this paper by means of experiments and modeling. First, an experimental campaign on spaced CLT panels and related results are presented. Then, both simplified and refined modelings are applied. The chosen accurate modeling is a periodic homogenization scheme handled by a plate theory [1] and based on unit-cell strain energy computation with FEM. It appears that the simplified approach can predict the bending stiffness (EI) of CLT panels with large voids but not their transverse shear stiffness (GA) which can be precisely predicted with the more refined modeling. Finally, the influence of several panel’s parameters on the mechanical response is pointed out as well.
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The Bending-Gradient Theory for the Linear Buckling of Thick Plates: Application to Cross-Laminated-Timber Panels

https://research.thinkwood.com/en/permalink/catalogue851
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Perret, Olivier
Lebée, Arthur
Douthe, Cyril
Sab, Karam
Publisher
ScienceDirect
Year of Publication
2016
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Bending-Gradient theory
Linear Buckling
Critical Load
Language
English
Research Status
Complete
Series
International Journal of Solids and Structures
Summary
In this paper, the linear buckling of a heterogeneous thick plate is studied using the Bending–Gradient theory which is an extension of the Reissner–Mindlin plate theory to the case of heterogeneous plates. Reference results are taken from a 3D numerical analysis using finite-elements and applied to Cross Laminated Timber panels which are thick and highly anisotropic laminates. First, it is shown that critical buckling loads are close to the material failure load which proves the necessity of a design model for the buckling of Cross Laminated Timber panels. Second, the soft simple support boundary condition is introduced as an opposition to the conventional hard simple support condition. It is shown that this distinction could be taken into account for designing timber structures depending on the accuracy needed. Third, it is observed that for varying plate geometries and arrangements, the Bending–Gradient theory predicts more precisely the critical load of CLT panels than classical lamination and first-order shear deformation theories. Finally, it is demonstrated that one of the suggested projections of the Bending–Gradient on a Reissner–Mindlin model gives very accurate results and could favorably allow the development of engineering recommendations for estimating properly transverse shear effects.
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Free
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Buckling of Cross Laminated Timber Walls

https://research.thinkwood.com/en/permalink/catalogue1615
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Perret, Olivier
Douthe, Cyril
Lebée, Arthur
Sab, Karam
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Mechanical Properties
Keywords
Linear Buckling
Finite Element
Buckling Loads
Boundary Conditions
Bending-Gradient theory
Transverse Shear Effects
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2360-2367
Summary
In this paper, the linear buckling of Cross Laminated Timber walls is investigated. A 3D numerical study using finite-elements is presented for several Cross Laminated Timber geometries, ply configurations and boundary conditions. First, it is shown that critical buckling loads are close to the material failure load which proves the necessity of a design model for the buckling of Cross Laminated Timber panels. Second, through a comparison between soft simple support boundary conditions and conventional hard simple support conditions, it is shown that this distinction could be taken into account for designing timber structures depending on the accuracy needed. Third, several plate models, particularly the Bending-Gradient theory, are compared to these 3D reference results. It is observed that for varying plate geometries and arrangements, the Bending-Gradient theory predicts more precisely the critical load of CLT panels than classical lamination and first-order shear deformation theories. Finally, it is demonstrated that one of the suggested projections of the Bending-Gradient on a Reissner-Mindlin model gives very accurate results and could favorably allow the development of engineering recommendations to estimate properly transverse shear effects.
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Free
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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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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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Influence of Orientation and Number of Layers on the Elastic Response and Failure Modes on CLT Floors: Modeling and Parameter Studies

https://research.thinkwood.com/en/permalink/catalogue1418
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Franzoni, Lorenzo
Lebée, Arthur
Lyon, Florent
Forêt, Gilles
Publisher
Springer Berlin Heidelberg
Year of Publication
2016
Country of Publication
Germany
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Failure Modes
Bending
Elastic Behavior
Language
English
Research Status
Complete
Series
European Journal of Wood and Wood Products
ISSN
1436-736X
Summary
In the present paper, the bending behavior of Cross Laminated Timber panels is investigated by means of the linear elastic exact solution from Pagano (1970; 1969). The resulting stresses are the input for a wood failure criterion, which can point out the first-crack load and the respective dominant failure mode. Heterogeneous layers are modeled as equivalent and homogeneous layers. This simplified and deterministic modeling gives results in good agreement with a reference experimental test. A comparison is made with respect to the panel’s global stiffness and failure stages within the apparent elastic stage. Finally, parameter studies are carried out, in order to quantify CLT limitations and advantages. The effect of varying properties like the panel’s slenderness, orientation of transverse layers and number of layers for a fixed total thickness are investigated.
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7 records – page 1 of 1.