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15 records – page 1 of 2.

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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Effects of Arrangement of Steel Plates on Strength of Dowel-Type Cross Laminated Timber Joints with Two Slotted-In Steel Plates Subjected to Lateral Force

https://research.thinkwood.com/en/permalink/catalogue1564
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Sawata, Kei
Kawamura, Hirokatsu
Takanashi, Ryuya
Ohashi, Yoshinori
Sasaki, Yoshihisa
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Dowel-Type Joints
Steel Plates
Johansen's Yield Model
Yield Modes
Strength
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 1556-1563
Summary
Cross-laminated timber (CLT) has received particular attention as a structural material, and its material and joint strengths have been researched. This study derived a strength formula for dowel-type CLT joints with slottedin two steel plates, based on Johansen’s yield theory. When the steel plate is inserted in CLT that has five laminae, the dowel-type joints with slotted-in two steel plates have thirty-nine yield modes. This study derived the formulas for each yield mode and compared them with experimentally obtained results. The yield mode assumed by the yield theory was congruent with the failure mode of the CLT specimens after the experiments. The strength of dowel-type joints calculated based on the yield theory was close to the yield strength obtained in the experiments.
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Energy Based Seismic Design of a Multi-Storey Hybrid Building: Timber-Steel Core Walls

https://research.thinkwood.com/en/permalink/catalogue1271
Year of Publication
2016
Topic
Seismic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Author
Goertz, Caleb
Organization
University of British Columbia
Year of Publication
2016
Country of Publication
Canada
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Topic
Seismic
Design and Systems
Keywords
Timber-Steel Hybrid
Core Walls
Multi-Storey
High Seismic Regions
Steel Plates
Equivalent Static Force Procedure
Nonlinear Time History Analysis
Language
English
Research Status
Complete
Summary
This thesis discusses a novel timber-steel core wall system for use in multi-storey buildings in high seismic regions. This hybrid system combines Cross Laminated Timber (CLT) panels with steel plates and connections to provide the required strength and ductility to core walled buildings. The system is first derived from first principles and validated in SAP2000. In order to assess the feasibility of the system it is implemented in the design of a 7-storey building based off an already built concrete benchmark building. The design is carried out following the equivalent static force procedure (ESFP) outlined by the National Building Code of Canada for Vancouver, BC. To evaluate the design bi-directional nonlinear time history analysis (NLTHA) is carried out on the building using a set of 10 ground motions based on a conditional mean spectrum. To improve the applicability of the hybrid system an energy based design methodology is proposed to design the timber-core walled building. The methodology is proposed as it does not rely on empirical formulas and force modification factors to determine the final design of the structure. NLTHA is carried out on the proposed methodology using 10 ground motions to evaluate the suitability of the method and the results are discussed and compared to the ESFP results.
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Experimental Study on Innovative Connections for Large Span Timber Truss Structures

https://research.thinkwood.com/en/permalink/catalogue47
Year of Publication
2015
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Yang, Huifeng
Crocetti, Roberto
Larsson, Gustaf
Gustafsson, Per-Johan
Publisher
International Association for Shell and Spatial Structures (IASS)
Year of Publication
2015
Country of Publication
Japan
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Connections
Mechanical Properties
Keywords
Reinforcement
Single Large Diameter Dowel Connection (SCDDC)
Full Scale
Tensile Tests
Quasi-Static
Steel Plates
Language
English
Conference
IASS WORKING GROUPS 12 + 18 International Colloquium 2015
Research Status
Complete
Notes
April 10-13, 2015, Tokyo, Japan
Summary
This paper summarizes an experimental investigation on several innovative reinforcing techniques for the “Single Large Diameter Dowel Connection”, SLDDC in timber truss structures. Besides lateral reinforcing or prestressing, also steel plates glued on two sides of the glulam specimens were used as reinforcing measure. To study the efficiency of these techniques, 15 full-scale quasi-static tensile tests on glulam members with a SLDDC on either ends of each member were performed. It was found that the reinforcement significantly enhanced the bearing capacity of the SLDDCs. All of the reinforcing techniques showed a satisfactory efficiency, preventing splitting of wood. Moreover, most of the specimens remains showed a remarkable post failure strength.
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Fire Behaviour of Dowel-Type Timber Connection with Slotted In Steel Plates Under Bending and Shear

https://research.thinkwood.com/en/permalink/catalogue1772
Year of Publication
2016
Topic
Connections
Fire
Material
Glulam (Glue-Laminated Timber)
Author
Zhang, Shengdong
Wang, Wan
Fan, Xinhai
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Connections
Fire
Keywords
Dowel-Type Connections
Steel Plates
Bending
Shear
Failure Modes
Charring Rate
Ambient Temperature
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 5317-5324
Summary
Investigations showed that large timber members exposed to fire have excellent fire-resistance. But very little research has been done on the performance of connections in timber structures exposed to fire. The dowel-type connections with slotted-in steel plates have widely been used in timber structures, sometime as moment resisting...
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Fire Performances of Timber-Cold Formed Thin Steel Plate Composite Beam

https://research.thinkwood.com/en/permalink/catalogue1707
Year of Publication
2016
Topic
Fire
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Steel-Timber Composite
Application
Beams
Author
Izumi, Bunji
Tani, Atsuko
Toba, Nobuaki
Nakashima, Koichiro
Koshihara, Mikio
Yamanashi, Tomohiko
Kohno, Mamoru
Winter, Wolfgang
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Steel-Timber Composite
Application
Beams
Topic
Fire
Mechanical Properties
Keywords
Steel Plates
Combustion Tests
Numerical Simulation
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4454-4461
Summary
The concept of combining folded thin steel plates and glued laminated timber in the beam element to gain increased structural and fire performances was developed at the Institute of Structural Design and Timber Engineering (ITI) in Vienna University of Technology...
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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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Load Distribution in Inclined Self-Tapping Screw Connections with Steel Side Plates

https://research.thinkwood.com/en/permalink/catalogue2652
Topic
Mechanical Properties
Connections
Application
Shear Walls
Beams
Author
Joyce, Tom
Organization
University of Alberta
Country of Publication
Canada
Application
Shear Walls
Beams
Topic
Mechanical Properties
Connections
Keywords
Self-Tapping Screws
Steel Plates
Strength
Stiffness
Research Status
In Progress
Summary
The objective of this research is to develop a model to predict the distribution of loads within connections with multiple self-tapping screw fasteners and steel side plates, and use this model to predict the strength and stiffness of multiple-inclined self-tapping screw connections. These results would facilitate the design of large scale connections with long rows of self-tapping screw fasteners, such as may be used for mass timber shear wall connections or splice joints for long-span timber beams.
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Load Distribution in Multi-Dowel Timber Connections Under Moment Loading - Integrative Evaluation of Multiscale Experiments

https://research.thinkwood.com/en/permalink/catalogue1499
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Author
Bader, Thomas
Schweigler, Michael
Hochreiner, Georg
Eberhardsteiner, Josef
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Topic
Connections
Mechanical Properties
Keywords
Load Distribution
Steel Dowels
Steel Plates
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 244-252
Summary
The load distribution in multi-dowel timber connections under bending moments was investigated by means of an integrative evaluation of a hierarchically organized test program, which encompassed component tests as well as single-dowel and multi-dowel connection tests. It was demonstrated that the anisotropic material behaviour of Laminated Veneer Lumber, and consequently of wood in general, leads to a non-uniform load distribution among the dowels, even for multi-dowel connections with a circular arrangement of dowels. Model predictions from this study highlight inefficiencies of the simplified calculation approach, based on the polar moment of inertia, i.e., based on isotropic theory. Loads of dowels loaded parallel to the grain were found to be underestimated by up to 50%. Through the hierarchically organized experimental campaign with full-field deformation measurement techniques, load distribution effects could be related to the orthotropic material behaviour of wood expressed in terms of load-to-grain angle dependent slip curves of single-dowel connections.
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Mechanical Behavior of Bolted Glulam Beam-to-Column Connections with Slotted-In Steel Plates Under Pure Bending

https://research.thinkwood.com/en/permalink/catalogue1503
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Columns
Author
Wang, Mingqian
Song, Xiaobin
Gu, Xianglin
Wu, Yajie
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Columns
Topic
Connections
Mechanical Properties
Keywords
Full Scale
Bolted Connection
Beam-to-Beam
Beam-to-Column
Steel Plates
Finite Element Model
Failure Modes
Moment Resistance
Continuum Damage Mechanics
Brittle Failure
Ductile Failure
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 309-316
Summary
In this study, five full-scale bolted glulam beam-to-beam connections with slotted-in steel plates were conducted under a third-point loading, and a three-dimensional finite element method based model was also established to investigate the failure modes and moment resistance of such connections. A material model based on the Continuum Damage Mechanics (CDM) theory was developed to predict damage evolution of wood. Different damage variables were used to consider the ductile and brittle failure modes of wood, respectively. The test results indicated that splitting and shear plug failures were the main failure modes. The numerical analysis model prediction achieved fair agreements with the test results. The research could provide the guide for the design of bolted beam-to-column connections in heavy timber structures.
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15 records – page 1 of 2.