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15 records – page 1 of 2.

Analysis of Shear Transfer and Gap Opening in Timber–Concrete Composite Members with Notched Connections

https://research.thinkwood.com/en/permalink/catalogue1399
Year of Publication
2017
Topic
Connections
Mechanical Properties
Material
Timber-Concrete Composite
Author
Boccadoro, Lorenzo
Steiger, René
Zweidler, Simon
Frangi, Andrea
Publisher
Springer Netherlands
Year of Publication
2017
Country of Publication
Netherlands
Format
Journal Article
Material
Timber-Concrete Composite
Topic
Connections
Mechanical Properties
Keywords
Notched Connections
Analytical Model
Shear Stress
Failure
Language
English
Research Status
Complete
Series
Materials and Structures
ISSN
1871-6873
Summary
In timber–concrete composite members with notched connections, the notches act as the shear connections between the timber and the concrete part, and have to carry the shear flow necessary for composite action. The shear transfer through the notches generates shear and tensile stresses in both parts of the composite member, which may lead to brittle failure and to an abrupt collapse of the structure. Although simplified design formulas already exist, some structural aspects are still not clear, and a reliable design model is missing. This paper summarizes current design approaches and presents analytical models to understand the shear-carrying mechanism, to estimate the shear stresses acting in the timber and concrete, and to predict failure. The analysis concentrates on three problems: the shearing-off failure of the timber close to the notch, the shear failure of the concrete, and the influence of the shear flow on the gap opening between the timber and concrete. Parts of the model calculations could be compared to experimental observations. The conclusions of this paper contribute to improving current design approaches.
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An Analytical, Numerical and Experimental Study of Non-Metallic Mechanical Joints for Engineered Timber Constructions

https://research.thinkwood.com/en/permalink/catalogue1606
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Author
Bazu, Gheorghe
Mahjourian Namari, Siavash
Wehsener, Jörg
Hartig, Jens
Haller, Peer
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Topic
Connections
Mechanical Properties
Keywords
GFRP
Densified Veneer Wood
Plates
Dowels
Load Bearing Behaviour
Analytical Model
Numerical Model
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2059-2068
Summary
Timber structures are strongly depending on the design of connections, which are mostly constructed from steel components. However, these joints have a number of limitations such as the tendency to be heavy, proneness to corrosion and often poor aesthetic appearances. Therefore, this study aims to replace metallic joints by non-metallic materials. An experimental testing program was performed to investigate the use of glass fiber reinforced plastics (GFRP), densified veneer wood (DVW) and laminated veneer lumber (LVL) in the form of plates and dowels in different test configurations. Analytical and numerical models were developed to better understand the load-bearing behaviour and to perform static verifications. The models were validated based on the experimental results. The results demonstrate that the use of GFRP dowels in combination with GFRP plates can provide a robust connection system for contemporary applications.
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Cross Laminated Timber at In-Plane Beam Loading – New Analytical Model Predictions and Relation to EC5

https://research.thinkwood.com/en/permalink/catalogue2232
Year of Publication
2018
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)

Cross Laminated Timber Reinforced with Carbon Fibre

https://research.thinkwood.com/en/permalink/catalogue2661
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Cao, Xinlei
Organization
University of Alberta
Country of Publication
Canada
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Carbon Fiber
Flexural Stiffness
Stress Distribution
Analytical Model
Finite Element Method (FEM)
Research Status
In Progress
Summary
Although engineered wood products such as glued laminated timber (glulam) and cross-laminated timber (CLT) have successfully eliminated the flaws inherently exist in conventional wood products, they are still not comparable with steel and concrete in terms of strength and stiffness. Among all different options for reinforcement, Carbon Fibre is relatively popular due to its high tensile strength, low weight, and easy installation. This study presents an analysis of flexural stiffness and stress distributions of CLT panels reinforced with carbon fibre mats, based on an analytical method and finite element method (FEM).
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Design Models for CLT Shearwalls and Assemblies Based on Connection Properties

https://research.thinkwood.com/en/permalink/catalogue369
Year of Publication
2014
Topic
Connections
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Author
Popovski, Marjan
Gavric, Igor
Organization
FPInnovations
Year of Publication
2014
Country of Publication
Canada
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Topic
Connections
Keywords
Lateral Loads
Analytical Model
North America
Europe
Language
English
Research Status
Complete
Summary
The work presented in this report is a continuation of the FPInnovations' research project on determining the performance of the CLT as a structural system under lateral loads. As currently there are no standardized methods for determining the resistance of CLT shearwalls under lateral loads, the design approaches are left at the descretion of the designers. The most common approach that is currently used in Europe and North America assumes that the resistance of CLT walls is a simple summary of the shear resistance of all connectors at the bottom of the wall. In this report some new analytical models for predicting the design (factored) resistance of CLT walls under lateral loads were developed based on connection properties. These new models were then evaluated for their consistency along with their models that are currently used in North America and in Europe.
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Effective Out-of-Plane Stiffness and Strength of Rotated Cross Laminated Timber Panels

https://research.thinkwood.com/en/permalink/catalogue1622
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Cheng, Alexandra
Schneider, Johannes
Tannert, Thomas
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Strength
Stiffness
Analytical Model
Finite Element Model
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2557-2564
Summary
This research considers the effect of in-plane rotation angles on the structural performance of Cross Laminated Timber (CLT) panels. In the interest of expanding the application of CLT to folded or freeform structures, rectangular CLT panels are likely to be divided into irregular geometries, in which case the loading will be applied at an intermediate orientation between the longitudinal and transverse panel axes. Such a loading condition is not accounted for in the existing analytical methods for dimensioning and designing with CLT. An analytical method is proposed which hybridizes the Shear Analogy method with Hankinson’s equation, allowing a designer to determine the effective stiffness of a CLT panel with any layup and at any in-plane rotation angle. An analytical study, followed by implementation with 3D parametric Finite Element Modelling and an experimental investigation, is used to evaluate this method. Results show that cross-grain/in-plane rotation has considerable effect on strength and stiffness of CLT panels with fewer than 5 laminations.
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Effect of Laminated Structure Design on the Mechanical Properties of Bamboo-Wood Hybrid Laminated Veneer Lumber

https://research.thinkwood.com/en/permalink/catalogue1407
Year of Publication
2017
Topic
Mechanical Properties
Design and Systems
Material
LVL (Laminated Veneer Lumber)
Other Materials
Author
Chen, Fuming
Deng, Jianchao
Li, Xingjun
Wang, Ge
Smith, Lee
Shi, Sheldon
Publisher
Springer Berlin Heidelberg
Year of Publication
2017
Country of Publication
Germany
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
Other Materials
Topic
Mechanical Properties
Design and Systems
Keywords
Bamboo
Poplar
Analytical Model
Density
MOE
MOR
Shear Strength
Glue Lines
Loading Tests
Language
English
Research Status
Complete
Series
European Journal of Wood and Wood Products
ISSN
1436-736X
Summary
The effects of veneer orientation and loading direction on the mechanical properties of bamboo-bundle/poplar veneer laminated veneer lumber (BWLVL) were investigated by a statistical analysis method. Eight types of laminated structure were designed for the BWLVL aiming to explore the feasibility of manufacturing high-performance bamboo-based composites. A specific type of bamboo species named Cizhu bamboo (Neosinocalamus affinis) with a thickness of 6 mm and diameter of 65 mm was used. The wood veneers were from fast-growing poplar tree (Populus ussuriensis Kom.) in China. The bamboo bundles were obtained by a mechanical process. They were then formed into uniform veneers using a onepiece veneer technology. Bamboo bundle and poplar veneer were immersed in water-soluble phenol formaldehyde (PF) resin with low molecular weight for 7 min and dried to MC of 8–12 % under the ambient environment. All specimens were prepared through hand lay-up using compressing molding method. The density and mechanical properties including modulus of elasticity (MOE), modulus of rupture (MOR), and shearing strength (SS) of samples were characterized under loading parallel and perpendicular to the glue line. The results indicated that as the contribution of bamboo bundle increased in laminated structure, especially laminated on the surface layers, the MOE, MOR and SS increased. A lay-up BBPBPBB (Bbamboo, P-poplar) had the highest properties due to the cooperation of bamboo bundle and poplar veneer. A higher value of MOE and MOR was found for the perpendicular loading test than that for the parallel test, while a slightly higher SS was observed parallel to the glue line compared with perpendicular loading. Any lay-up within the homogeneous group can be used to replace others for obtaining the same mechanical properties in applications. These findings suggested that the laminated structure with high stiffness laid-up on the surface layers could improve the performance of natural fiber reinforced composites.
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In-Plane Stiffness of CLT Panels With and Without Openings

https://research.thinkwood.com/en/permalink/catalogue1668
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Shahnewaz, Md
Tannert, Thomas
Alam, Shahria
Popovski, Marjan
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Mechanical Properties
Keywords
In-Plane Loading
Finite Element Analysis
Elastic Stiffness
Openings
Thickness
Aspect Ratios
Analytical Model
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3813-3820
Summary
The research presented in this paper analysed the stiffness of Cross-Laminated-Timber (CLT) panels under in-plane loading. Finite element analysis (FEA) of CLT walls was conducted. The wood lamellas were modelled as an orthotropic elastic material, while the glue-line between lamellas were modelled using non-linear contact elements. The FEA was verified with test results of CLT panels under in-plane loading and proved sufficiently accurate in predicting the elastic stiffness of the CLT panels. A parametric study was performed to evaluate the change in stiffness of CLT walls with and without openings. The variables for the parametric study were the wall thickness, the aspect ratios of the walls, the size and shape of the openings, and the aspect ratios of the openings. Based on the results, an analytical model was proposed to calculate the in-plane stiffness of CLT walls with openings more accurately than previously available models from the literature.
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The Lateral Load Resistance of Unclassified Cross-Laminated Timber Walls: Experimental Tests and Theoretical Approach

https://research.thinkwood.com/en/permalink/catalogue1294
Year of Publication
2018
Topic
Mechanical Properties
Seismic
Wind
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Wadi, Husam
Amziane, Sofiane
Taazount, Mustapha
Publisher
ScienceDirect
Year of Publication
2018
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Mechanical Properties
Seismic
Wind
Keywords
Lateral Loading
Fasteners
Analytical Model
Language
English
Research Status
Complete
Series
Engineering Structures
Summary
This paper focuses mainly on the mechanical behaviour of unclassified cross-laminated timber walls under lateral loading (seismic and wind loads). Unclassified wooden planks were used to construct the wall unit with an odd number of layers (three) for each wall, with the planks in each layer in a perpendicular relative orientation. In this research, an experimental study of large-scale timber walls was carried out with a view to determining the lateral load resistance. Diagonal struts, under tension and compression were employed on the cross-laminated walls to investigate the effects of these elements on the lateral resistance of the wall. A theoretical approach has been developed to describe the overall behaviour of the cross-laminated wall and to investigate the internal forces on the fasteners. The present work is then compared to Oriented Strand Board (OSB) panel designs. Based on the data and results obtained from the experimental tests, this study confirms, firstly, that cross-laminated walls without a diagonal strut have approximately double the horizontal strength of (OSB) npanels, secondly, that diagonal strut significantly increases the lateral load resistance of cross-laminated walls, particularly under compression conditions, and thirdly, the proposed theoretical approach shows similar performance to the average experimental test up to 100 mm of overall lateral displacement of cross-laminated timber wall.
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Modelling the Effects of Wood Cambial Age on the Effective Modulus of Elasticity of Poplar Laminated Veneer Lumber

https://research.thinkwood.com/en/permalink/catalogue1417
Year of Publication
2016
Topic
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Author
Girardon, Stéphane
Denaud, Louis
Pot, Guillaume
Rahayu, Istie
Publisher
Springer Paris
Year of Publication
2016
Country of Publication
France
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
Topic
Mechanical Properties
Keywords
Poplar
Modulus of Elasticity
Analytical Model
Bending
Thickness
Language
English
Research Status
Complete
Series
Annals of Forest Science
ISSN
1297-966X
Summary
A modelling method is proposed to highlight the effect of cambial age on the effective modulus of elasticity of laminated veneer lumber (LVL) according to bending direction and veneer thickness. This approach is relevant for industrial purposes in order to optimize the performance of LVL products. LVL is used increasingly in structural applications. It is obtained from a peeling process, where product’s properties depend on cambial age, hence depend on radial position in the log. This study aims to highlight how radial variations of properties and cambial age impact the mechanical behaviour of LVL panels. An analytical mechanical model has been designed to predict the modulus of elasticity of samples made from poplar LVL panels. The originality of the model resides in the integration of different data from the literature dealing with the variation in wood properties along the radius of the log. The simulation of the peeling process leads to veneers with different mechanical properties, which are randomly assembled in LVL panels. The model shows a correct mechanical behaviour prediction in comparison with experimental results of the literature, in particular with the decrease in MOE in LVL made of juvenile wood. It highlights that the bending direction and veneer thickness have no influence on the average MOE, but affect MOE dispersion. This paper proposed an adequate model to predict mechanical behaviour in the elastic domain of LVL panels based on the properties of raw wood material.
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15 records – page 1 of 2.