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10 records – page 1 of 1.

Extended End Plate Semi-Rigid Composite Joints with CLT Panels and Demountable Shear Connectors

https://research.thinkwood.com/en/permalink/catalogue2059
Year of Publication
2018
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Frames

Stochastic Model for Predicting the Bending Strength of Glued-Laminated Timber Based on the Knot Area Ratio and Localized MOE in Lamina

https://research.thinkwood.com/en/permalink/catalogue1379
Year of Publication
2018
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Pang, Sung-Jun
Oh, Jung-Kwon
Hong, Jung-Pyo
Lee, Sang-Joon
Lee, Jun-Jae
Publisher
Springer Japan
Year of Publication
2018
Country of Publication
Japan
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Mechanical Properties
Keywords
Stochastic Model
Bending Strength
Modulus of Elasticity
Tensile Strength
Knot Area Ratios
Language
English
Research Status
Complete
Series
Journal of Wood Science
ISSN
1611-4663
Summary
The aim of this study was to develop a stochastic model for predicting the bending strength distribution of glued-laminated timber (GLT). The developed model required the localized modulus of elasticity (MOE) and tensile strengths of laminae as input properties. The tensile strength was estimated using a regression model based on the localized MOEs and knot area ratios (KAR) which were experimentally measured for lamina grades samples. The localized MOE was obtained using a machine stress-rated grader, and the localized KAR was determined using an image-processing system. The bending strength distributions in four types of GLTs were simulated using the developed GLT beam model; these four types included: (1) GLT beams without finger joints; (2) GLT beams with finger joints; (3) GLT beams with different lamina sizes; and (4) GLT beams with different combinations of lamina grades. The simulated bending strength distributions were compared with actual test data of 2.4 and 4.8 m-long GLTs. The Kolmogorov–Smirnov goodness-of-fit tests showed that all of the simulated bending strength distributions agreed well with the test data. Especially, good agreement was shown in the fifth percentile point estimate of bending strength with the difference of approximately 1%.
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Advanced Wood-Based Solutions for Mid-Rise and High-Rise Construction: Structural Performance of Post-Tensioned CLT Shear Walls with Energy Dissipators

https://research.thinkwood.com/en/permalink/catalogue1472
Year of Publication
2018
Topic
Design and Systems
Mechanical Properties
Seismic
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
LSL (Laminated Strand Lumber)
Application
Shear Walls
Author
Chen, Zhiyong
Popovski, Marjan
Symons, Paul
Organization
FPInnovations
Year of Publication
2018
Country of Publication
Canada
Format
Report
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
LSL (Laminated Strand Lumber)
Application
Shear Walls
Topic
Design and Systems
Mechanical Properties
Seismic
Keywords
Compression Tests
Compression Strength
Energy Dissipation
Post-Tensioned
Pres-Lam
Monotonic Loading
Reverse Cyclic Loading
Language
English
Research Status
Complete
Summary
The latest developments in seismic design philosophy have been geared towards developing of so called "resilient" or "low damage" innovative structural systems that can reduce damage to the structure while offering the same or higher levels of safety to occupants. One such innovative structural system is the Pres-Lam system that is a wood-hybrid system that utilizes post-tensioned (PT) mass timber components in both rigid-frame and wall-based buildings along with various types of energy disspators. To help implement the Pres-Lam system in Canada and the US, information about the system performance made with North American engineered wood products is needed. That information can later be used to develop design guidelines for the designers for wider acceptance of the system by the design community.Several components influence the performance of the Pres-Lam systems: the load-deformation properties of the engineered wood products under compression, load-deformation and energy dissipation properties of the dissipators used, placement of the dissipators in the system, and the level of post-tensioning force. The influence of all these components on the performance of Pres-Lam wall systems under gravity and lateral loads was investigated in this research project. The research project consisted of two main parts: material tests and system tests.
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Probabilistic Models for the Withdrawal Behavior of Single Self-Tapping Screws in the Narrow Face of Cross Laminated Timber (CLT)

https://research.thinkwood.com/en/permalink/catalogue1388
Year of Publication
2018
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Brandner, Reinhard
Ringhofer, Andreas
Grabner, Martin
Publisher
Springer Berlin Heidelberg
Year of Publication
2018
Country of Publication
Germany
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Axial Load
Self-Tapping Screws
Withdrawal
Probabilistic Model
Language
English
Research Status
Complete
Series
European Journal of Wood and Wood Products
ISSN
1436-736X
Summary
Cross laminated timber (CLT) and self-tapping screws have strongly dominated the latest developments in timber engineering. Although knowledge of connection techniques in traditional light-frame structures can be applied to solid timber constructions with CLT, there are some product specifics requiring additional attention; for example in positioning of fasteners, differentiation in the side face and narrow face of the panels and the influence of potential gaps. The load–displacement behaviour of single, axially-loaded self-tapping screws positioned in the narrow face of CLT and failing in withdrawal was investigated. For the first time a multivariate probabilistic model was formulated together with models relating the parameters with the thread-fibre angle and the density. Different types and widths of gaps, initial slip and / or delayed stiffening as well as softening after exceeding of the maximum load can be considered. Beyond the scope of this contribution, the probabilistic model is seen as a worthwhile basis for investigations into the withdrawal behaviour of primary axially loaded, compact groups of screws positioned in timber products and subjected to withdrawal failure.
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Free
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Long-Term Behavior of Steel-CLT Connections

https://research.thinkwood.com/en/permalink/catalogue2080
Year of Publication
2018
Topic
Connections
Serviceability
Mechanical Properties
Material
Steel-Timber Composite
CLT (Cross-Laminated Timber)
Application
Floors

Characterization and Structural Performance in Bending of CLT Panels Made from Small-Diameter Logs of Loblolly/Slash Pine

https://research.thinkwood.com/en/permalink/catalogue2214
Year of Publication
2018
Topic
Design and Systems
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Baño, Vanesa
Godoy, Daniel
Figueredo, Diego
Vega, Abel
Publisher
MDPI
Year of Publication
2018
Country of Publication
Switzerland
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Design and Systems
Mechanical Properties
Keywords
Bending Strength
Small Diameter
Language
English
Research Status
Complete
Series
Materials
ISSN
1996-1944
Online Access
Free
Resource Link
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Connection and Performance of Two-Way CLT Plates

https://research.thinkwood.com/en/permalink/catalogue1482
Year of Publication
2018
Topic
Mechanical Properties
Connections
Material
CLT (Cross-Laminated Timber)
Application
Floors
Roofs
Author
Zhang, Chao
Lee, George
Lam, Frank
Organization
University of British Columbia
Year of Publication
2018
Country of Publication
Canada
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Floors
Roofs
Topic
Mechanical Properties
Connections
Keywords
Two-Way
Bending Test
Modulus of Elasticity
Self-Tapping Screws
Glued-In-Rod
Steel Connectors
Steel Plates
Language
English
Research Status
Complete
Summary
The two-way action of Cross Laminated Timber (CLT) is often ignored in the design of CLT due to its complexity. But in some cases, for example, large span timber floor/roof, the benefit of taking the two-way action into account may be considerable since it is often deflection controlled in the design. Furthermore CLT panels are typically limited to widths of less than 3 m. therefore, for practical applications, engaging CLT panels in two-way action as a plate in bending would require connecting two panels in the width/minor direction to take out-of-plane loading. To address this technically difficult situation, an innovative connection was developed to join the CLT panels in the minor direction to form a large continuous two-way plate. The two-way action of CLT was also quantified. Static bending test was conducted on CLT panels in the major and minor directions to measure the Modulus of Elasticity (MOE). This provided a benchmark for the following connection test, and data for the future development of computer modeling. The average apparent MOE was 9.09 GPa in the major direction and 2.37 GPa in the minor direction. Several connection techniques were considered and tested, including self-tapping wood screws, glued in steel rods, and steel connectors. One connecting system was found to be effective. For the panel configuration considered, the system was consisted of steel plates, self-tapping wood screws, and 45° screw washers. Two steel plates were placed on the tension side with sixteen screws, and one steel plates was placed on the compression side with four screws. When the screws were driven into the wood, the screws were tightly locked with the washers and steel plates, and at the same time, the wood members were pulled together by the screws. This eliminated any original gap within the connection. The connector was installed to join two CLT members in the minor direction. They were tested under bending with the same setup as above. The connected panels had an average apparent MOE of 2.37 GPa, and an average shear-free MOE of 2.44 GPa, both of which were higher than the counterpart in the full panels. The moment capacity of the connected panels was also high. The minimum moment capacity was 3.2 times the design value. Two large CLT panels were tested under concentrated loading with four corners simply supported. The deflection of nine locations within the panels was measured. This data will be used to validate the computer modeling for CLT two-way action.
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Advanced Wood-Based Solutions for Mid-Rise and High-Rise Construction: Proposed Vibration-Controlled Design Criterion for Supporting Beams

https://research.thinkwood.com/en/permalink/catalogue1178
Year of Publication
2018
Topic
Acoustics and Vibration
Mechanical Properties
Application
Floors
Author
Hu, Lin
Organization
FPInnovations
Year of Publication
2018
Country of Publication
Canada
Format
Report
Application
Floors
Topic
Acoustics and Vibration
Mechanical Properties
Keywords
Floor Supporting Beam
Bending Stiffness
Language
English
Research Status
Complete
Summary
For wood floor systems, their vibration performance is significantly dependent on the conditions of their supports, specifically the rigidity of the support. Detrimental effects could result if the floor supports do not have sufficient rigidity. This is special ture for floor supporting beams. The problem of vibrating floor due to flexible supporting beams can be solved through proper design of the supporting beams. However, there is currently no criterion set for the minimum requirement for floor supporting beam stiffness to ensure the beam is rigid enough. Designers’ current practice is to use the uniform load deflection criteria specified in the code for designing the supporting beams. This criterion is based on certain ratios of the floor span (e.g. L/360, L/480 etc.). The disadvantage of this approach is that it allows larger deflections for longer-span beams than for shorter beams. This means that engineers have to use their experience and judgement to select a proper ratio, particularly for the long-span beams. Therefore, a better vibration-controlled design criterion for supporting beams is needed. It is recommended to further verify the ruggedness of the proposed stiffness criterion for floor supporting beams using new field supporting beam data whenever they become available.
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Free
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Comparison of Theoretical and Laboratory Out-of-Plane Shear Stiffness Values of Cross Laminated Timber Panels

https://research.thinkwood.com/en/permalink/catalogue2177
Year of Publication
2018
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Niederwestberg, Jan
Zhou, Jianhui
Chui, Ying-hei
Publisher
MDPI
Year of Publication
2018
Country of Publication
Switzerland
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Shear Behaviour
Out Of Plane
Shear Stiffness
Timoshenko Theory of Bending
Shear Modulus
Language
English
Research Status
Complete
Series
Buildings
ISSN
2075-5309
Online Access
Free
Resource Link
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10 records – page 1 of 1.