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17 records – page 1 of 2.

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
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
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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Application of Modern Wood Product Glulam in Timber Frame with Tenon- Mortise Joints and its Structural Behavior

https://research.thinkwood.com/en/permalink/catalogue2469
Year of Publication
2019
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)

Behaviour of Multi-Storey Cross-Laminated Timber Buildings Under Lateral Loading

https://research.thinkwood.com/en/permalink/catalogue2715
Year of Publication
2020
Topic
Connections
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Hughes, Claire
Publisher
Queen's University Belfast
Year of Publication
2020
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Connections
Design and Systems
Keywords
Lateral Loading
Tall Wood
Tall Timber Buildings
Connections
Monotonic Loading Tests
Constant Vertical Load
Wall Systems
Experimental Tests
Analytical Approach
Multi-Storey
Research Status
Complete
Summary
In response to the global drive towards sustainable construction, CLT has emerged as a competitive alternative to other construction materials. CLT buildings taller than 10-storeys and CLT buildings in regions of moderate to high seismicity would be subject to higher lateral loads due to wind and earthquakes than CLT buildings which have already been completed. The lack of structural design codes and limited literature regarding the performance of CLT buildings under lateral loading are barriers to the adoption of CLT for buildings which could experience high lateral loading. Previous research into the behaviour of CLT buildings under lateral loading has involved testing of building components. These studies have generally been limited to testing wall systems and connections which replicate configurations at ground floor storeys in buildings no taller than three storeys. Consequently, to develop the understanding of the performance of multi-storey CLT buildings under lateral loading, the performance of wall systems and connections which replicate conditions of those in above ground floor storeys in buildings taller than three storeys were experimentally investigated. The testing of typical CLT connections involved testing eighteen configurations under cyclic loading in shear and tension. The results of this experimental investigation highlighted the need for capacity-based design of CLT connections to prevent brittle failure. It was found that both hold down and angle bracket connections have strength and stiffness in shear and tension and by considering the strength of the connections in both directions, more economical design of CLT buildings could be achieved. The testing of CLT wall systems involved testing three CLT wall systems with identical configurations under monotonic lateral load and constant vertical load, with vertical loads replicating gravity loads at storeys within a 10-storey CLT building. The results show that vertical load has a significant influence on wall system behaviour; varying the vertical load was found to vary the contribution of deformation mechanisms to global behaviour within the elastic region, reinforcing the need to consider connection design at each individual storey. As there are still no structural design codes for CLT buildings, the accuracy of analytical methods presented within the literature for predicting the behaviour of CLT connections and wall systems under lateral loading was assessed. It was found that the analytical methods for both connections and wall systems are highly inaccurate and do not reflect experimentally observed behaviour.
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Composite CLT-Glulam Double-T Panels

https://research.thinkwood.com/en/permalink/catalogue2645
Topic
Mechanical Properties
Connections
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Floors
Roofs
Organization
Fast + Epp
University of Northern British Columbia
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Floors
Roofs
Topic
Mechanical Properties
Connections
Keywords
Vibration
Stiffness Properties
Strength
Screw
Vibration Test
Monotonic Loading Tests
GCWood
Research Status
In Progress
Summary
To support the associated Sir Matthew Begbie Elementary School and Bayview Elementary School projects in pushing the boundaries forward for long-span floor and roof construction, this testing project aims to compare different connection approaches for composite connections between glulam and cross-laminated timber (CLT) – for vibration, stiffness, and strength. Working with the University of Northern British Columbia (UNBC), Fast + Epp aimed to complete a series of vibration and monotonic load tests on 30’ long full-scale double-T ribbed panels. The tests consisted of screws in withdrawal, screws in shear, and nominal screws clamping with glue. Both the strength and stiffness are of interest, including slip stiffness of each connection type. This physical testing was completed in January and February 2020, where the full composite strength of each system was reached. Initial data analysis has provided information for comparison with existing models for shear connection stiffness. Publications will follow in 2021.
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Conventional and Novel Timber Steel Hybrid Connections: Testing, Performance and Assessment

https://research.thinkwood.com/en/permalink/catalogue187
Year of Publication
2015
Topic
Connections
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Schneider, Johannes
Organization
University of British Columbia
Year of Publication
2015
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Connections
Seismic
Keywords
Timber-Steel Hybrid
Fasteners
Quasi-Static
Monotonic Loading
Cyclic Loading
Brackets
Tube Connections
Research Status
Complete
Summary
The focus of this research is the connection between steel frame and the infill wall. Over 100 conventional bracket-type connections with various combinations of bracket and fasteners with cross-laminated timber were tested, investigated and assessed for damage under seismic loading protocols for a hybrid application. An energy-based formulation according to Krätzig was applied to calculate the development of the damage index, and the resulting index was validated with visual observation. Six of the connections were modeled in OpenSees. For the modeling, a CUREE-10 parameter model was chosen to reproduce the test curves. The load-displacement results from both test and model were analyzed; the first method according to ASTM standards, where the envelope curve of the hysteretic results are considered and plotted in an equivalent energy elastic-plastic curve (EEEP). The second analyzing method used, was Krätzig’s damage accumulation model. Throughout all six combinations and both loading directions (parallel- and perpendicular-to-the-grain) a major difference was found in the analyzing methods. The EEEP curve roughly approximates the performance but with the damage accumulation method showed that analysis of the subsequent cycles is required to better reflect the empirical performance of the connections. To avoid the extensive destruction of a bracket type connection after completion of seismic loadings, a new approach was chosen. It was found that a tube connection can obtain comparably similar strength results as a conventional bracket connection. The computed mechanical properties of bracket-type and tube-type connections were compared and evaluated. The new tube connection showed great potential for future timber-steel hybrid structures and their connecting challenge. A total of 27 connection assemblies were tested under quasi-static monotonic and reversed cyclic loads. The tube connections showed two major differences when compared to traditional bracket connections: i) the completely linear elastic behaviour at the beginning, and ii) the continued load increase after yielding. Both phenomena are founded in the geometry of that connector effectively making the novel connector a very promising alternative.
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Cyclic Load Behaviour of Beam-to-Column Glulam Joints Combining Glued-in Rods with Steel Brackets

https://research.thinkwood.com/en/permalink/catalogue2028
Year of Publication
2018
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Ling, Zhibin
Liu, Weiqing
Yang, Huifeng
Xiang, Zhe
Year of Publication
2018
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Beam-to-Column
Joints
Glued-In Rods
Steel Brackets
Cyclic Loading
Monotonic Loading
Failure Modes
Stiffness
Ductility
Energy Dissipation
Hysteresis Loop
Douglas-Fir
Conference
World Conference on Timber Engineering
Research Status
Complete
Summary
This paper presents an experimental campaign conducted on the beam-to-column glulam joints combing glued-in rods and steel brackets (BCGS glulam joints) aiming to investigate the mechanical behaviour of these glulam joints under low cyclic loading. Three types of steel brackets were designed for connecting the beam and column combing with glued-in rods and to work as energy dissipaters. In each group of specimens (except for group MJ4), two specimens were tested under monotonic loading and the others were subjected to low cyclic loading. The test results were summarized comprehensively in terms of failure modes, joint stiffness, hysteresis loops, ductility and energy dissipation ability. Generally, the difference of load capacity between BCGS glulam joints and the beam-to-column glulam joints only with glued-in rods (BCG glulam joints) was not significant. The joint stiffness of BCG glulam joints was higher than that of the BCGS glulam joints, while the stiffness degradation of the later is slower than the former. The hysteresis loops of the BCGS glulam joints exhibited less pinching effect obviously compared with the BCG glulam joints, which indicated that the energy dissipation ability of the glulam joints with glued-in rods could be improved significantly by using the steel brackets as energy dissipaters. Moreover, it should be noted that the hysteresis loops of groups CJ1 showed slipping effect obviously during testing. This might due to the insufficient shear resistance of these two groups, so that further investigations on BCG glulam joints with shear-resisting components are urgently needed.
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Ductility and Overstrength of Dowelled LVL and CLT Connections Under Cyclic Loading

https://research.thinkwood.com/en/permalink/catalogue1504
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
Author
Ottenhaus, Lisa-Mareike
Li, Minghao
Smith, Tobias
Quenneville, Pierre
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
Topic
Connections
Mechanical Properties
Keywords
Ductility
Overstrength
Cyclic Loading
Monotonic Loading
Dowels
Ductile Failure
Brittle Failure
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 325-333
Summary
This paper presents an experimental study on ductility and overstrength of dowelled connections. Connection ductility and overstrength derived from monotonic testing are often used in timber connection design in the context of seismic loading, based on the assumption that these properties are similar under monotonic and cyclic loading. This assumption could possibly lead to non-conservative connection design. Therefore, it is necessary to quantify ductility and overstrength for cyclic loading and contrast them with their monotonic performance. For this purpose, monotonic and quasi-static cyclic experimental tests were performed on dowelled LVL and CLT connections. The experimental results were also compared with strength predictions from state-of-the-art analytical models in literature that were verified for ductile and brittle failure under monotonic loading. This work also allowed investigation into a generally applicable overstrength factor for push-pull loaded dowelled connections.
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High-Capacity Hold-Down for Tall Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue1529
Year of Publication
2016
Topic
Design and Systems
Seismic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Wood Building Systems
Author
Zhang, Xiaoyue
Popovski, Marjan
Tannert, Thomas
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Wood Building Systems
Topic
Design and Systems
Seismic
Mechanical Properties
Keywords
Holz-Stahl-Komposit
Hold-Down
Seismic Load
Strength
Stiffness
Ductility
Failure Mechanisms
Quasi-Static
Monotonic Loading
Reverse Cyclic Loading
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 725-732
Summary
The structural use of wood in North America is dominated by light wood-frame construction used in low-rise and – more recently – mid-rise residential buildings. Mass timber engineered wood products such as laminatedveneer-lumber and cross-laminated timber (CLT) panels enable to use the material in tall and large wood and woodbased hybrid buildings. The prospect of constructing taller buildings creates challenges, one of them being the increasein lateral forces created by winds and earthquakes, thus requiring stronger hold-down devices. This paper summarises the experimental investigation on the performance a high-capacity hold-down for resisting seismic loads in tall timberbased structural systems. The connection consists of the Holz-Stahl-Komposit-System (HSK)™ glued into CLT with the modification that ductile steel yielding was allowed to occur inside the CLT panel. The strength, stiffness, ductility and failure mechanisms of this connection were evaluated under quasi-static monotonic and reversed cyclic loading. The results demonstrate that the modified hold-down-assembly provides a possible solution for use in tall timber-based structures in high seismic zones
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Lateral Resistance of Cross-Laminated Timber Panel-to-Panel Connections

https://research.thinkwood.com/en/permalink/catalogue1724
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Author
Richardson, Benjamin
Hindman, Daniel
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Topic
Connections
Mechanical Properties
Keywords
Strength
Stiffness
Panel-to-Panel
Monotonic Loading
Cyclic Loading
Half-Lap
Butt-Joint
Steel Plate
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4655-4662
Summary
Cross laminated timber (CLT) connections in shearwalls require an understanding of the shear strength and stiffness of panel-to-panel connections within the wall. This research measures the strength and stiffness of three different panel-to-panel CLT connections considering both monotonic and cyclic loading. Connections included a laminated veneer lumber (LVL) spline, a half-lap connection and a butt joint with overlapping steel plate. All connections were ductile in nature. The butt joint with steel plate demonstrated the highest connection strength of the connections tested. The cyclic stiffness of the laminated veneer lumber spline was less than the monotonic stiffness, while the halflap joint experienced a sharp drop in load after ultimate load was achieved. Full details of the monotonic and cyclic behaviour will be discussed, including load, stiffness and ductility terms.
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Mechanical Behaviour of Bolted Glulam Beam-to-Column Connections

https://research.thinkwood.com/en/permalink/catalogue479
Year of Publication
2014
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Columns
Author
Song, Xiaobin
Wang, Mingqian
Gu, Xianglin
Luo, Lie
Zhang, Yunfan
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Columns
Topic
Connections
Mechanical Properties
Keywords
Beam-to-Column
Mechanical Behaviour
Monotonic Loading
Reverse Cyclic Load
Stiffness
Maximum Moment
finite element method
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
This paper presents the results of an on-going program of the mechanical behaviour of bolted glulam beamto-column connections. The program included testing and modelling of connections of various bolt size, edge distance and lamina alignment patterns. This paper presents part of the obtained results, including monotonic and reversed cyclic loading test results of 10 full-scale beam-to-column connections and the corresponding modelling results. The test results indicated that the perpendicular-to-grain properties of glulam and the localized contact between the bolts and surrounding glulam had significant influence on the stiffness and the maximum moment of the connections. A finite element method based model, which can be easily incorporated in commercial available software packages, was developed and verified based on the test results. Good agreement was achieved. Parametric study results indicated that the tolerance of the bolt holes can significantly affect the mechanical behaviour of the bolted beam-to-column connections.
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17 records – page 1 of 2.