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49 records – page 1 of 5.

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
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
Conference
Euromech Colloquim 556 Theoretical Numerical and Experimental Analyses of Wood Mechanics
Research Status
Complete
Notes
May 2015, Dresde, Germany
Summary
Cross Laminated Timber (CLT) panels are more and more common in timber construction. When submitted to out-of-plane loads, they can be considered as multi-layer plates with anisotropic behaviour. Their main structural issue is the low transverse shear strength of cross layers which leads to rolling shear failure. In addition the fabrication process can include or not lateral boards’ gluing. The resulting discontinuities can be considered as weakly heterogeneous and influence the mechanical response. Moreover the timber construction market requires new technical solutions for CLT, like periodic voids within the panel. This solution leads to lighter and more thermally efficient floors. However, the spaced voids between boards increase the heterogeneity of the panel and therefore the complexity of stresses’ distribution.
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An Accurate One-Dimensional Theory for the Dynamics of Laminated Composite Curved Beams

https://research.thinkwood.com/en/permalink/catalogue889
Year of Publication
2014
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Carpentieri, Gerardo
Tornabene, Francesco
Ascione, Luigi
Fraternalia, Fernando
Publisher
ScienceDirect
Year of Publication
2014
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Mechanical Properties
Keywords
Dynamic Behavior
Mechanical Theory
Finite Element Model
Bending
Shear
Deformation
Research Status
Complete
Series
Journal of Sound and Vibration
Summary
We model the dynamic behavior of laminated curved beams on the assumption that the different layers of such structures are perfectly bonded at the interface and can show different flexural rotations from one another. We formulate a mechanical theory and a finite element model accounting for bending, shear, warping and extensional deformation modes, as well as radial, tangential and rotary inertias. The main novelty of the proposed theory consists of a generalization of layer-wise displacement approaches available in literature to the dynamics of beams with finite curvature. The work includes some numerical results related to the free vibration of laminated arches and showing different support conditions and aspect ratios to establish comparisons with different theories in the literature. We observe that an accurate mechanical modeling of curved laminated beams is crucial for correct estimation of the eigenfrequencies and eigenmodes of such structures within a 1D framework.
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Analysis of the Timber-Concrete Composite Systems with Ductile Connection

https://research.thinkwood.com/en/permalink/catalogue113
Year of Publication
2013
Topic
Mechanical Properties
Material
Timber-Concrete Composite
Author
Zhang, Chao
Organization
University of Toronto
Year of Publication
2013
Format
Thesis
Material
Timber-Concrete Composite
Topic
Mechanical Properties
Keywords
Bending
Ductility
Model
Load Deflection
Tension
Shear Connection
Research Status
Complete
Summary
In timber-concrete composite systems, timber and concrete are inherently brittle materials that behave linearly elastic in both tension and bending. However, the shear connection between the members can exhibit significant ductility. It is therefore possible to develop timber-concrete composite systems with ductile connection that behave in a ductile fashion. This study illustrates the use of an elastic-perfectly plastic analytical approach to this problem. In addition, the study proposes an incremental method for predicting the nonlinear load-deflection response of the composite system. The accuracy of the analytical model is confirmed with a computer model, and numerical solutions of the analytical model are compared to experimental results from the bending tests conducted by previous researchers. Reasonable agreement is found from the comparisons, which validates the capacity of the analytical model in predicting the structural behaviour of the timber-concrete composite systems in both elastic and post-elastic stages.
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An Improved Model for the Fire Design of Cross Laminated Timber in Bending

https://research.thinkwood.com/en/permalink/catalogue1940
Year of Publication
2018
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Author
Schmid, Joachim
Klippel, Michael
Fahrni, Reto
Frangi, Andrea
Tiso, Mattia
Just, Alar
Werther, Norman
Organization
ETH Zurich
Tallinn University of Technical
Technical University Munich
Year of Publication
2018
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Fire Resistance
Model
Zero-Strength Layer
Cross-Section
Bending
Strength
Stiffness
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 20-23, 2018, Seoul, Republic of Korea
Summary
In this study, new design models for cross-laminated timber (CLT) are developed to verify the fire resistance up to 120 minutes. This is done aiming for the popular Effective Cross-Section Method using a so-called zero-strength layer (ZSL) to account for losses in strength and stiffness. This was done using a method earlier presented at WCTE 2010 and discussed with the European industry. To allow for improvements, (a) the current CLT product portfolio was analysed and thermal and mechanical simulations were done accordingly for initially unprotected and unprotected members. Further, (b) new definitions for the ZSL were used to allow for a higher accuracy of the simplified models. As anoutcome, a model with (1) tabulated data between 7.0 and 12.0 mm for the effective ZSL only considering longitudinal layers and (2) a simplified model “twelve and two” is proposed for CLT members in bending.
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Bending and Rolling Shear Capacities of Southern Pine Cross Laminated Timber (CLT)

https://research.thinkwood.com/en/permalink/catalogue1596
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Gu, Mengzhe
Pang, Weichiang
Stoner, Michael
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Southern Pine
US
Manufacturing
Rolling Shear
Bending
Three Point Bending Test
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 1899-1906
Summary
Southern Pine (SP) is one of the fastest growing softwood species in the Southern Forest of United States. With its high strength to weight ratio, SP becomes an ideal candidate for manufacturing engineered wood products such as cross laminated timber (CLT). Two batches of CLT panels were manufactured using visually graded SP lumbers in this study: pilot-scale panels in a laboratory setting and full-size panels in a manufacturing plant environment. The first batch of pilot-scale CLT panels was manufactured at Clemson University. The second batch of full-scale CLT panels (3m x 12.2m) was produced and CNC-sized by Structurlam in Penticton, Canada and shipped to Clemson University for testing. Four types of structural wood adhesives were selected in the panel production, namely Melamine Formaldehyde (MF), Phenol Resorcinol Formaldehyde (PRF), Polyurethane (PUR) and Emulsion Polymer Isocyanate (EPI). This paper presents the manufacturing process of SP CLT in a laboratory setting as well as structural performance verification of 3- ply SP CLT in terms of rolling shear and bending properties. The obtained performance data of 3-ply CLT in both major and minor strength directions is verified against PRG-320 Standard for Performance Rated Cross Laminated Timber. Tested results are presented and discussed.
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Bending and Rolling Shear Properties of Cross-Laminated Timber Fabricated with Canadian Hemlock

https://research.thinkwood.com/en/permalink/catalogue2407
Year of Publication
2019
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls
Floors
Wood Building Systems

Bending, Shear, and Compressive Properties of Three- and Five-Layer Cross-Laminated Timber Fabricated with Black Spruce

https://research.thinkwood.com/en/permalink/catalogue2589
Year of Publication
2020
Topic
Design and Systems
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
He, Minjuan
Sun, Xiaofeng
Li, Zheng
Feng, Wei
Publisher
SpringerOpen
Year of Publication
2020
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Design and Systems
Mechanical Properties
Keywords
Black Spruce
Panels
Bending
Thickness
Research Status
Complete
Series
Journal of Wood Science
Summary
Cross-laminated timber (CLT) is an innovative engineering wood product made by gluing layers of solid-sawn lumber at perpendicular angles. The commonly used wood species for CLT manufacturing include spruce-pine-fir (SPF), douglas fir-larch, and southern pine lumber. With the hope of broadening the wood species for CLT manufacturing, the purposes of this study include evaluating the mechanical properties of black spruce CLT and analyzing the influence of CLT thickness on its bending or shear properties. In this paper, bending, shear, and compressive tests were conducted respectively on 3-layer CLT panels with a thickness of 105 mm and on 5-layer CLT panels with a thickness of 155 mm, both of which were fabricated with No. 2-grade Canadian black spruce. Their bending or shear resisting properties as well as the failure modes were analyzed. Furthermore, comparison of mechanical properties was conducted between the black spruce CLT panels and the CLT panels fabricated with some other common wood species. Finally, for both the CLT bending panels and the CLT shear panels, their numerical models were developed and calibrated with the experimental results. For the CLT bending panels, results show that increasing the CLT thickness whilst maintaining identical span-to-thickness ratios can even slightly reduce the characteristic bending strength of the black spruce CLT. For the CLT shear panels, results show that increasing the CLT thickness whilst maintaining identical span-to-thickness ratios has little enhancement on their characteristic shear strength. For the CLT bending panels, their effective bending stiffness based on the Shear Analogy theory can be used as a more accurate prediction on their experiment-based global bending stiffness. The model of the CLT bending specimens is capable of predicting their bending properties; whereas, the model of the CLT shear specimens would underestimate their ultimate shear resisting capacity due to the absence of the rolling shear mechanism in the model, although the elastic stiffness can be predicted accurately. Overall, it is attested that the black spruce CLT can provide ideal bending or shear properties, which can be comparable to those of the CLT fabricated with other commonly used wood species. Besides, further efforts should focus on developing a numerical model that can consider the influence of the rolling shear mechanism.
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Butt-Joint Bonding of Timber as a Key Technology for Point-Supported, Biaxial Load Bearing Flat Slabs Made of Cross-Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue2466
Year of Publication
2019
Topic
Mechanical Properties
Connections
Material
CLT (Cross-Laminated Timber)
Author
Zöllig, Stefan
Muster, Marcel
Themessl, Adam
Publisher
IOP Publishing Ltd
Year of Publication
2019
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Connections
Keywords
Butt-Joint
Bending Strength
Shear Resistance
Research Status
Complete
Series
IOP Conference Series: Earth and Environmental Science
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CLT Panels Subjected to Combined Out-of-Plane Bending and Compressive Axial Loads

https://research.thinkwood.com/en/permalink/catalogue1729
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Wang, Jasmine
Mohammad, Mohammad
Di Lenardo, Bruno
Sultan, Mohamed
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Out Of Plane
Bending
Compressive Axial Loads
Canada
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4738-4745
Summary
With the introduction of Cross Laminated Timber (CLT) into North America and gaining popularity it is of interest to the design and code development community to have codified provisions to facilitate the design of CLT structures. This paper addresses the design aspect of CLT panels subjected to combined bending and compressive axial loads. Fifteen specimens covering different combinations of grades and layups of commercially available Canadian CLT panels were tested at different eccentricities to validate the proposed interaction equation. Testing program was reported in this paper and the test data was compared with the model prediction. It was concluded that the current nonlinear interaction equation given in the Canadian timber design standard (CSA O86) for timber and glulam tends to overestimate the capacity of CLT wall panel. A linear interaction equation was found to be appropriate
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Connection and Performance of Two-Way CLT Plates Phase II

https://research.thinkwood.com/en/permalink/catalogue2086
Year of Publication
2019
Topic
Mechanical Properties
Connections
Material
CLT (Cross-Laminated Timber)
PSL (Parallel Strand Lumber)
LVL (Laminated Veneer Lumber)
Author
Zhang, Chao
Asselstine, Julian
Lee, George
Lam, Frank
Organization
University of British Columbia
Year of Publication
2019
Format
Report
Material
CLT (Cross-Laminated Timber)
PSL (Parallel Strand Lumber)
LVL (Laminated Veneer Lumber)
Topic
Mechanical Properties
Connections
Keywords
Deflection
Two-Way
Bending
Finite Element Method
Model
Research Status
Complete
Summary
In Phase I of Developing Large Span Two Way CLT Floor System (2017-18) we studied the performance of a steel plate connection system for the minor direction of CLT plates. The connected specimens had higher stiffness and strength compared to intact members under bending. In Phase II (2018-19) we designed and tested another connector based on...
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49 records – page 1 of 5.