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10 records – page 1 of 1.

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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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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Shear Connections with Self-Tapping-Screws for Cross-Laminated-Timber Panels

https://research.thinkwood.com/en/permalink/catalogue1531
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Hossain, Afrin
Popovski, Marjan
Tannert, Thomas
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Self-Tapping Screws
Joints
Quasi-Static
Capacity
Stiffness
Yield Strength
Ductility
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 756-763
Summary
The research presented in this paper examines the performance of 3-ply and 5-ply Cross-laminated Timber (CLT) panels connected with Self-tapping Screws (STS). Different conventional joint types (surface spline with STS in shear and half-lap joints with STS in either shear or withdrawal) along with two innovative solutions were evaluated in a total of 198 quasi-static tests. The first novel assembly used STS with double inclination of fasteners in butt joints; the second was a combination of STS in withdrawal and shear in lap joints. The joint performance was evaluated in terms of capacity, stiffness, yield strength, and ductility. The results confirmed that joints with STS in shear exhibited high ductility but low stiffness, whereas joints with STS in withdrawal were found to be stiff but less ductile. Combining the shear and withdrawal action of STS led to high stiffness and high ductility.
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Shear Connections with Self-Tapping-Screws for Cross-Laminated-Timber Panels

https://research.thinkwood.com/en/permalink/catalogue432
Year of Publication
2015
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Hossain, Afrin
Lakshman, Ruthwik
Tannert, Thomas
Organization
Structures Congress
Publisher
American Society of Civil Engineers
Year of Publication
2015
Country of Publication
United States
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Connections
Mechanical Properties
Keywords
Ductility
Self-Tapping Screws
Stiffness
Strength
Vertical Shear Loading
Mid-Scale
Quasi-Static
Shear Tests
Language
English
Conference
Structures Congress 2015
Research Status
Complete
Notes
April 23–25, 2015, Portland, Oregon, USA
Summary
Cross-Laminated-Timber (CLT) is increasingly gaining popularity in residential and non-residential applications in North America. To use CLT as lateral load resisting system, individual panels need to be connected. In order to provide in-plane shear connections, CLT panels may be joined with a variety of options including the use of self-tapping-screws (STS) in surface splines and half-lap joints. Alternatively, STS can be installed at an angle to the plane allowing for simple butt joints and avoiding any machining. This study investigated the performance of CLT panel assemblies connected with STS under vertical shear loading. The three aforementioned options were applied to join 3ply and 5-ply CLT panels. A total of 60 mid-scale quasi-static shear tests were performed to determine and compare the connection performance in terms of strength, stiffness, and ductility. It was shown that – depending on the screw layout – either very stiff or very ductile joint performance can be achieved.
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Performance of Timber-Concrete Composite Floors Using Flat-Plate Engineered Wood Products

https://research.thinkwood.com/en/permalink/catalogue1618
Year of Publication
2016
Topic
Mechanical Properties
Material
Timber-Concrete Composite
CLT (Cross-Laminated Timber)
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
Application
Floors
Author
Gerber, Adam
Popovski, Marjan
Tannert, Thomas
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Timber-Concrete Composite
CLT (Cross-Laminated Timber)
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
Application
Floors
Topic
Mechanical Properties
Keywords
Strength
Stiffness
Small Scale
Shear Tests
Elastic Stiffness
Quasi-Static
Loading
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2397-2406
Summary
Timber-Concrete Composite (TCC) systems are comprised of a timber element connected to a concrete slab through a mechanical shear connection. A large number of T-beam configurations currently exist; however, the growing availability of panel-type engineered wood products (EWPs) in North America in combination with a concrete topping has offered designers and engineers greater versatility in terms of architectural expression and structural and building physics performance. The focus of this investigation was to experimentally determine the properties for a range of TCC systems in several EWPs. Strength and stiffness properties were determined for different TCC configurations based on small-scale shear tests. Eighteen floor panels were tested for elastic stiffness under a quasi-static loading protocol and measurements of the dynamic properties were obtained prior to loading to failure. The tests confirmed that calculations according to the -method can predict the basic stiffness and dynamic properties of TCC floors within a reasonable degree of accuracy. Floor capacities were more difficult to predict, however, failure occurred at loads that were between four and ten times serviceability requirements. The research demonstrated that all selected connector configurations produced efficient timber-concrete-composite systems.
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Strength and Stiffness of CLT Shear Walls in Platform Construction

https://research.thinkwood.com/en/permalink/catalogue1976
Year of Publication
2018
Topic
Design and Systems
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls
Wood Building Systems

Seismic Performance of Embedded Steel Beam Connection in Cross-Laminated Timber Panels for Tall-Wood Hybrid System

https://research.thinkwood.com/en/permalink/catalogue415
Year of Publication
2017
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Author
Zhang, Xiaoyue
Azim, Riasat
Bhat, Pooja
Popovski, Marjan
Tannert, Thomas
Publisher
Canadian Science Publishing
Year of Publication
2017
Country of Publication
Canada
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Topic
Seismic
Keywords
Timber-Steel Hybrid
Energy Dissipation
FFTT
Quasi-Static
Monotonic Test
Reverse Cyclic Test
Failure mechanism
Beam Profiles
Embedment
Language
English
Research Status
Complete
Series
Canadian Journal of Civil Engineering
Summary
Recent developments in novel engineered mass timber products and connection systems have created the possibility to design and construct tall timber-based buildings. This research presents the experiments conducted on the steel-wood connection as main energy dissipating part of a novel steel–timber hybrid system labelled Finding the Forest Through the Trees (FFTT). The performance was investigated using quasi-static monotonic and reversed cyclic tests. The influence of different steel beam profiles (wide flange I-sections and hollow rectangular sections), and the embedment approaches (partial and full embedment) was investigated. The test results demonstrated that appropriate connection layouts can lead to the desired failure mechanism while avoiding excessive crushing of the mass timber panels. The research can serve as a precursos for developing design guidelines for the FFTT systems as an option for tall wood-hybrid building systems in seismic regions.
Copyright
Courtesy of Canadian Science Publishing
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Group Effect for Self-Tapping-Screws in CLT Subjected to Shear and Axial Loads

https://research.thinkwood.com/en/permalink/catalogue1975
Year of Publication
2018
Topic
Design and Systems
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls
Wood Building Systems

Timber-Concrete Composites Using Flat-Plate Engineered Wood Products

https://research.thinkwood.com/en/permalink/catalogue616
Year of Publication
2015
Topic
Design and Systems
Connections
Material
CLT (Cross-Laminated Timber)
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Author
Gerber, Adam
Tannert, Thomas
Organization
Structures Congress
Publisher
American Society of Civil Engineers
Year of Publication
2015
Country of Publication
United States
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Topic
Design and Systems
Connections
Keywords
Concrete Topping
Mid-Scale
Push-Out Tests
Language
English
Conference
Structures Congress 2015
Research Status
Complete
Notes
April 23–25, 2015, Portland, Oregon, USA
Summary
Timber-Concrete Composite (TCC) systems have been employed as an efficient solution in medium span structural applications; their use remains largely confined to European countries. TCC systems are generally comprised of a timber and concrete element with a shear connection between. A large number of precedents for T-beam configurations exist; however, the growing availability of flat plate engineered wood products (EWPs) in North America has offered designers greater versatility in terms of floor plans and architectural expression in modern timber and hybrid structures. The opportunity exists to enhance the strength, stiffness, fire, and vibration performance of floors using these products by introducing a concrete topping, connected to the timber to form a composite. A research program at the University of British Columbia Vancouver investigates the performance of five different connector types (a post-installed screw system, cast-in screws, glued-in steel mesh, adhesive bonded, and mechanical interlocking) in three different EWPs (Cross-Laminated-Timber, Laminated-Veneer-Lumber, and Laminated-Strand-Lumber). Over 200 mid-scale push-out tests were performed in the first stage of experimental work to evaluate the connector performance and to optimize the design of subsequent vibration and bending testing of full-scale specimens, including specimens subjected to long-term loading.
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Internal Perforated-steel-plate Connections with Self-Drilling Dowels for Cross-laminated Timber

https://research.thinkwood.com/en/permalink/catalogue2807
Year of Publication
2020
Topic
Connections
Seismic
Wind
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Author
Drexler, Maximilian
Tannert, Thomas
Organization
University of Northern British Columbia
Year of Publication
2020
Country of Publication
Canada
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Topic
Connections
Seismic
Wind
Keywords
Lateral Load Resisting System
Shear Walls
CSA 086
Internal-Perforated-Steel-Plates
Self-drilling Dowels
Language
English
Research Status
Complete
Summary
Cross-laminated timber (CLT) constitutes a promising solution for numerous structural applications, including for large and tall residential and commercial buildings. The prospect of building larger timber structures creates some structural challenges, amongst them being that lateral forces created by high winds and strong earthquakes are higher and create higher demands of “holddowns”. The Canadian Standard for Engineering Design in Wood CSA-O86 does not (yet) provide any specific procedures to estimate the resistance of mass-timber Lateral Load Resisting Systems (LLRS) nor how to facilitate the targeted kinematic mode, especially for multi-panel walls where the LLRS behaviour is a function of connection behaviour. The project investigated the viability of internal-perforated-steel-plates (ISP) with self-drilling dowels as high-performance connections for CLT LLRS. The project objective was to contribute towards the development of reliable design guidance for ISP connections. To achieve this objective, first at the material level, the properties of the used steel-plates and dowels were verified. Then, at the component level, the performance of shear connections and hold-downs were investigated by performing quasi-static monotonic and reversed cyclic tests. The most significant finding of the component level tests was the proof that it is possible to control the strength, stiffness, and ductility only through the IPSP and avoid bending of the SDD or crushing of the wood. Furthermore, the length of the steel perforations had a large impact on the performance with the steel-plates with the long slots (Type-D and Type-E) exhibiting lower strength and stiffness. For the hold-down tests, the same perforation geometry as for the shear-connection tests was chosen. As already determined in the shear-connection tests, the hold-down specimens with the short perforation slots resulted in the strongest and stiffest connection. The results from this project will be used to design and test CLT shear walls with ISP connections.
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10 records – page 1 of 1.