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13 records – page 1 of 2.

Experimental investigation of the moment-rotation behaviour of beam-column connections produced using compressed wood connectors

https://research.thinkwood.com/en/permalink/catalogue3104
Year of Publication
2022
Topic
Mechanical Properties
Connections
Material
DLT (Dowel Laminated Timber)
Author
Mehra, Sameer
O'Ceallaigh, Conan
Sotayo, Adeayo
Guan, Zhongwei
Harte M. Annette
Organization
National University of Ireland
University of Liverpool
Publisher
Elsevier
Year of Publication
2022
Format
Journal Article
Material
DLT (Dowel Laminated Timber)
Topic
Mechanical Properties
Connections
Keywords
Compressed Wood
Moment-Rotation Behaviour
Dowel Type Connections
Research Status
Complete
Series
Construction and Building Materials
Summary
The use of timber in construction in medium–high rise construction has increased in recent years largely due to the significant innovation in engineered wood products and connection technology coupled with a desire to utilise more environmentally sustainable construction materials. While engineered wood products offer a low-carbon solution to the construction industry, the widespread use of adhesive and metallic fasteners often limits the recyclability of the structural components at the end of life of the structure and it may be beneficial to reduce this where possible. To establish the possibility of an all-wood connection solution, this preliminary study examines a series of beam-column connections designs to evaluate the relative performance of the different designs, which are connected with modified or compressed wood (CW) connectors. The connection designs are formed between glued-laminated beam and column members in the first instance and later examined when connecting dowel-laminated timber (DLT) members. The results show that significant moment capacity and rotational stiffness can be achieved for connections solely connected using CW fasteners. Furthermore, the all-wood solution utilising CW fasteners to connect DLT members has also demonstrated significant moment capacity and rotational stiffness capacity without the use of adhesive and metallic components.
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Mechanical Behavior of GFRP Dowel Connections to Cross Laminated Timber-CLT Panels

https://research.thinkwood.com/en/permalink/catalogue2957
Year of Publication
2022
Topic
Connections
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Author
Almeida, Amanda
Moura, Jorge
Organization
Maringá State University
Londrina State University
Editor
Knapic, Sofia
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Topic
Connections
Keywords
GFRP
Dowel-Type Connections
Panel-to-Panel
Design Methodology
Push-Out Tests
Research Status
Complete
Series
Forests
Summary
Sustainability issues are driving the civil construction industry to adopt and study more environmentally friendly technologies as an alternative to traditional masonry/concrete construction. In this context, plantation wood especially stands out as a constituent of the cross-laminated timber (CLT) system, laminated wood glued in perpendicular layers forming a solid-wood structural panel. CLT panels are commonly connected by screws or nails, and several authors have investigated the behavior of these connections. Glass-fiber-reinforced polymer (GFRP) dowels have been used to connect wooden structures, and have presented excellent performance results; however, they have not yet been tested in CLT. Therefore, the objective of this study is to analyze the glass-fiber-reinforced polymer (GFRP)-doweled connections between CLT panels. The specimens were submitted to monotonic shear loading, following the test protocol described in EN 26891-1991. Two configurations of adjacent five-layer panels were tested: flat-butt connections with 45° dowels (x, y, and z axes), and half-lap connections with 90° dowels. The results were evaluated according to the mechanical connection properties of strength, stiffness, and ductility ratio. The results showed higher stiffness for butt-end connections. In terms of strength, the half-lap connections were stronger than the butt-end connections.
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Experimental characterisation of the moment-rotation behaviour of beam-beam connections using compressed wood connectors

https://research.thinkwood.com/en/permalink/catalogue3131
Year of Publication
2021
Topic
Connections
Author
Mehra, Sameer
O'Ceallaigh, Conan
Sotayo, Adeayo
Guan, Zhongwei
Harte, Annette M.
Organization
National University of Ireland Galway
University of Liverpool
Publisher
Elsevier
Year of Publication
2021
Format
Journal Article
Topic
Connections
Keywords
Compressed Wood Connectors
Dowel-Type Connections
Eurocode 5
Moment Rotation Behaviour
Beam-beam Connections
Research Status
Complete
Series
Engineering Structures
Summary
The widespread use of energy-intensive metallic connectors and synthetic adhesives in modern timber construction has negative implications for the end-of-life disposal or re-use of the structural timber components. Therefore, it is favourable to substitute metallic connectors and synthetic adhesives with bio-based alternatives such as wood-based connectors. Recent studies have shown that densified or compressed wood (CW) with superior mechanical properties could be suitable for the manufacture of wood-based connectors in the form of CW dowels and CW plates. This study experimentally examines the moment-rotation behaviour of semi-rigid type timber-CW beam-beam connections under pure bending. The study also assesses the suitability of current design rules to predict the moment capacity of timber-CW connections. The comparative study has shown that the moment capacity of the timber-CW connection can be conservatively predicted from the characteristic load-carrying capacity of the connections calculated using the EC 5 strength equations.
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Ductility of Dowelled New Zealand Douglas-Fir CLT Connections Under Monotonic and Cyclic Loading

https://research.thinkwood.com/en/permalink/catalogue2114
Year of Publication
2019
Topic
Connections
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Author
Ottenhaus, Lisa-Mareike
Li, Minghao
Brown, J.
Ravn, C.
Scott, B.
Organization
University of Canterbury
Year of Publication
2019
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Topic
Connections
Keywords
Multi-Story
Douglas-Fir
Dowel-Type Connections
Dowels
Conference
Pacific Conference on Earthquake Engineering
Research Status
Complete
Summary
Cross-laminated Timber (CLT) is gaining popularity in Australasia as a building material for multi-storey structures. For multi-storey timber buildings located in seismic areas, designing strong but ductile hold-downs for CLT shear walls can be challenging and requires careful structural connection design. In this study, dowelled connections in New Zealand Douglas-Fir (D.Fir) CLT with inserted steel plates were experimentally investigated as a solution for hold-downs in multi-storey timber buildings. The dowel group spacing was varied for CLT3 (3-ply, 135 mm thick), CLT5 (5-ply, 175 mm thick) and CLT7 (7-ply, 275 mm thick) D.Fir CLT to investigate the spacing impact on ductility of the hold-down connections under both monotonic and quasi-static cyclic loading. These results were also compared with past similar testing of dowelled connections in 5-ply (150 mm) Radiata Pine CLT. A total of 12 monotonic and 36 quasi-static cyclic tests were carried out and it was observed that increased dowel spacing increases ductility with similar strength when compared to past more dense dowel spacing tests. Furthermore, to deter the onset of tension perpendicular to grain brittle failure, fully threaded screws and nuts were added to the dowelled connection and the impact of this is discussed.
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Embedment Strength of Cross-Laminated Timber for Smooth Dowel-type Fasteners

https://research.thinkwood.com/en/permalink/catalogue2118
Year of Publication
2019
Topic
Connections
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Dong, Weiqun
Li, Qiao
Zhang, Hao
Wang, Zhiqiang
Zhou, Jianhui
Gong, Meng
Year of Publication
2019
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Connections
Design and Systems
Keywords
Fasteners
Embedment Strength
Failure Modes
Embedment Tests
Dowel-Type Connections
Conference
International Conference on Advances in Civil Engineering and Materials
Research Status
Complete
Series
MATEC Web of Conferences
Summary
Embedment strength is a significant property in the dowel type connection in timber structure, i.e. cross-laminated timber (CLT). The CLT design properties are different from those of sawn timber (ST) and glued-laminated timber (GLT) because of the orthogonal structure, which may particularly have influence on the design of connections. The layup feature, i.e. the thickness ratio of transverse layer (TRTL) was considered as an effective factor on CLT embedment strength in this study, except for other factors, i.e. wood density, smooth dowel diameter, and loading angle. Approximate 660 embedment tests were performed according to ASTM D5764 half-hole test method. A few of existing design models for CLT embedment strength were evaluated using experimental data. It was found that different factors had different effect tendency and each factor had statistically significant impact on CLT embedment strength. The embedment strength and failure modes of CLT were obviously different from those of GLT due to the existence of transverse layer in CLT. The existing design equations should be improved. Based on the test results, a new design equation was proposed which had better prediction.
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Ductility of Large-scale Dowelled CLT Connections under Monotonic and Cyclic Loading

https://research.thinkwood.com/en/permalink/catalogue2254
Year of Publication
2017
Topic
Connections
Material
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
Application
Shear Walls
Author
Ottenhaus, Lisa-Mareike
Li, Minghao
Smith, Tobias
Organization
University of Canterbury
Year of Publication
2017
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
Application
Shear Walls
Topic
Connections
Keywords
Dowel-Type Connections
Ductility
Particle Tracking Velocimetry
Tall Timber
Radiata Pine
Conference
Australian Earthquake Engineering Society Conference
Research Status
Complete
Summary
In the last decade, several tall timber buildings have been constructed in Europe, North America and Australasia. Often engineered wood products such as Cross Laminated Timber (CLT) are used in combination with strong connections to construct timber buildings exceeding 10 storeys. For tall timber buildings located in seismic areas it can be challenging to design strong yet ductile hold-downs in CLT shear walls. One common solution is to use dowelled connections with inserted steel plates. Design code calculation rules for timber connections are usually derived from smallscale testing assuming that strength and ductility properties can be extrapolated for larger connections in actual buildings. For CLT connections, fastener spacing requirements are derived in a similar manner under the general assumption that brittle failure modes can be prevented due to the reinforcing effect of cross-layers in CLT. In order to assess the validity of these assumptions, experiments were conducted on different layouts of small-scale and large-scale dowelled connections in CLT, Laminated Veneer Lumber (LVL) as well as a LVL-CLT hybrid, all made out of New Zealand Radiata pine. The tests comprised of 40 small and 12 large samples subjected to monotonic and cyclic loading. Strength and ductility were compared between the different connection sizes and layouts. For the large-scale connections, particle tracking velocimetry (PTV) was used for the first time to measure displacements.
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Lateral Load-Resisting System Using Mass Timber Panel for High-Rise Buildings

https://research.thinkwood.com/en/permalink/catalogue1221
Year of Publication
2017
Topic
Seismic
Wind
Design and Systems
Material
LSL (Laminated Strand Lumber)
Application
Shear Walls
Hybrid Building Systems
Author
Chen, Zhiyong
Chui, Ying-hei
Publisher
Frontiers Media
Year of Publication
2017
Format
Journal Article
Material
LSL (Laminated Strand Lumber)
Application
Shear Walls
Hybrid Building Systems
Topic
Seismic
Wind
Design and Systems
Keywords
Lateral Load Resisting System
High-Rise
Dowel-Type Connections
FE model
Linear Static Analysis
Non-linear Dynamic Analysis
Timber-Steel Hybrid
Research Status
Complete
Series
Frontiers in Built Environment
Summary
As global interest in using engineered wood products in tall buildings intensifies due to the “green” credential of wood, it is expected that more tall wood buildings will be designed and constructed in the coming years. This, however, brings new challenges to the designers. One of the major challenges is how to design lateral load-resisting systems (LLRSs) with sufficient stiffness, strength, and ductility to resist strong wind and earthquakes. In this study, an LLRS using mass timber panel on a stiff podium was developed for high-rise buildings in accordance with capacity-based design principle. The LLRS comprises eight shear walls with a core in the center of the building, which was constructed with structural composite lumber and connected with dowel-type connections and wood–steel composite system. The main energy dissipating mechanism of the LLRS was detailed to be located at the panel-to-panel interface. This LLRS was implemented in the design of a hypothetical 20-storey building. A finite element (FE) model of the building was developed using general-purpose FE software, ABAQUS. The wind-induced and seismic response of the building model was investigated by performing linear static and non-linear dynamic analyses. The analysis results showed that the proposed LLRS using mass timber was suitable for high-rise buildings. This study provided a valuable insight into the structural performance of LLRS constructed with mass timber panels as a viable option to steel and concrete for high-rise buildings.
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Timber Trusses Made of European Beech LVL

https://research.thinkwood.com/en/permalink/catalogue1527
Year of Publication
2016
Topic
Connections
Design and Systems
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Application
Trusses
Author
Kobel, Peter
Frangi, Andrea
Steiger, René
Year of Publication
2016
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Application
Trusses
Topic
Connections
Design and Systems
Mechanical Properties
Keywords
Europe
Beech
Dowel-Type Connections
Ductile Failure
Embedment Tests
Embedment Strength
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 667-674
Summary
This paper presents an experimental and analytical investigation on the application of laminated veneer lumber (LVL) made of European beech wood (fagus sylvatica L.) in timber truss structures. Particular focus is laid on developing improved design approaches for dowel-type connections and on promoting ductile failure behaviour, as the connections in timber trusses are generally governing the performance of the whole structure. Embedment tests were carried out in order to assess the embedment strength values for beech LVL, which are necessary to design dowel-type connections. The results showed higher values for beech LVL, as compared to estimations using existing formulas from design codes. A series of tensile connection tests showed that, using cross-layered beech LVL, ductile dowel-type connections with high load-carrying capacities can be designed, given that premature brittle failures are prevented. Lastly, tests on full truss structures confirmed that the favourable behaviour of dowel-type connections in cross-layered beech LVL can be implemented in truss systems, improving the global behaviour of the whole structural element.
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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
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
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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Effect of Array on Tensile Load Carrying Capacity CLT Drift Pinned Joint

https://research.thinkwood.com/en/permalink/catalogue1532
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Nakashima, Shoichi
Kitamori, Akihisa
Araki, Yasuhiro
Isoda, Hiroshi
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Reduction Coefficients
Dowel-Type Connections
Drift Pinned Joint
Tensile Tests
Stiffness
Proportional Limit Load
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 772-779
Summary
A reduction coefficient is applied in usual design of multiple dowels type connections. The numbers of stiffeners in row is one of important factor to decide this coefficient. CLT drift pinned joint showed small orthotropy against in plane tensile load. Tensile tests of multiple drift pins joints were performed to evaluate the effect of array. Numbers of drift pins n in each specimen were same (n=12), but the arrangements were different (2 x 6, 3 x 4, 4 x 3, 6 x 2). Also the grain directions were parameters (0, 90 degrees). The reduction of initial stiffness and proportional limit load showed good agreement between theoretical prediction and experimental results.
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13 records – page 1 of 2.