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13 records – page 1 of 2.

Behavior of Cross-Laminated Timber Diaphragm Panel-to-Panel Connections with Self-Tapping Screws

https://research.thinkwood.com/en/permalink/catalogue1422
Year of Publication
2017
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Sullivan, Kyle
Organization
Oregon State University
Year of Publication
2017
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Keywords
Lateral Load Resisting System
Monotonic Tests
Cyclic Tests
Strength
Stiffness
Self-Tapping Screws
International Building Code
Research Status
Complete
Summary
The goal of this project is to contribute to the development of design values for cross-laminated timber (CLT) diaphragms in the seismic load-resisting system for buildings. Monotonic and cyclic tests to determine strength and stiffness characteristics of 2.44 m (8 ft) long shear connections with common self-tapping screws were performed. Understanding and quantifying the behavior of these shear connections will aid in developing design provisions in the National Design Specification for Wood Construction and the International Building Code so structural engineers can use CLT more confidently in lateral force-resisting systems and extend the heights of wood buildings. Experimental strength-to-design strength ratios were in the range of 2.1 to 8.7. In the ASCE 41 acceptance criteria analysis, the m-factors for the Life Safety performance level in cyclic tests ranged from 1.6 to 1.8 for surface spline connections and from 0.9 to 1.7 for cyclic half-lap connections. The half-lap connections, where screws were installed in withdrawal, shear, shear, and withdrawal, performed exceptionally well with both high, linear-elastic, initial stiffness, and ductile, post-peak behavior.
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Design of Floor Diaphragms in Multi-Storey Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue294
Year of Publication
2015
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Floors
Author
Moroder, Daniel
Smith, Tobias
Pampanin, Stefano
Palermo, Alessandro
Buchanan, Andrew
Year of Publication
2015
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Floors
Topic
Design and Systems
Seismic
Keywords
Diaphragms
Multi-Storey
Commercial
Lateral Loads
Equivalent Truss Method
Lateral Load Resisting System
Conference
New Zealand Society for Earthquake Engineering Conference
Research Status
Complete
Notes
April 10-12, 2015, Rotorua, New Zealand
Summary
This paper discusses the design of timber diaphragms, in response to the growing interest in multi-storey commercial timber structures, and the lack of guidance or regulations regarding the seismic design of timber diaphragms. Proper performance of floor diaphragms is required to transfer all lateral loads to the vertical systems that resist them, but design for earthquake loads can be more complex than design for wind loads. This paper confirms that the seismic design of a diaphragm is intimately linked to the seismic design of the whole building. Diaphragm failure, even if restricted to a limited diaphragm portion, can compromise the behaviour of the whole building. It is therefore necessary to design and detail diaphragms for all possible load paths and to evaluate their influence on the load distribution within the rest of the structure. It is strongly recommended that timber diaphragms be designed as elastic elements, by applying dynamic amplification and overstrength factors derived from the lateral load resisting system. This paper shows that some current design recommendations for plywood sheathing on light timber framing can be applied to massive wood diaphragms, but for more complex floor geometries an equivalent truss method is suggested. Diaphragm flexibility and displacement incompatibilities between the floor diaphragms and the lateral resisting systems also need to be accounted for.
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Experimental Investigation of Self-Centering Cross Laminated Timber Walls

https://research.thinkwood.com/en/permalink/catalogue1654
Year of Publication
2016
Topic
Seismic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Ganey, Ryan
Berman, Jeffrey
Yao, Lihong
Dolan, Daniel
Akbas, Tugce
Loftus, Sara
Sause, Richard
Ricles, James
Pei, Shiling
van de Lindt, John
Blomgren, Hans-Erik
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Seismic
Mechanical Properties
Keywords
Lateral Load Resisting System
Post-Tensioning
U-Shaped Flexural Plates
Limit States
Self-Centering
Strength
Stiffness
Interstory Drifts
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3547-3554
Summary
This paper describes experiments conducted to develop a resilient lateral force resisting wall system that combines cross-laminated timber (CLT) panels with vertical post-tensioning (PT) to provide post-event re-centering. Supplemental mild steel U-shaped flexural plate devices (UFPs) are intended to yield under cyclic loading while the PT and CLT components remain undamaged until large inter-story drifts are experienced by the wall. The experiments were designed to explore various limit states for self-centering CLT (SC-CLT) walls, including their dependence on design variables and their impact on performance, and to investigate strength and stiffness degradation at large interstory drifts. It was found that the SC-CLT walls were able to re-center even after large drift cycles and the crushing of the CLT material was the governing limit sate for most specimens. A hierarchy of desirable limit states was identified consisting of UFP yielding, CLT splitting, PT yielding, and CLT crushing.
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Experimental Study on the Lateral Resistance of Reinforced Glued-Laminated Timber Post and Beam Structures

https://research.thinkwood.com/en/permalink/catalogue2867
Year of Publication
2017
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Author
Xiong, Haibei
Liu, Yingyang
Yao, Ya
Li, Bingyang
Organization
Tongji University
Zhengzhou University
Publisher
Taylor&Francis Group
Year of Publication
2017
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Topic
Mechanical Properties
Keywords
Post and Beam
Lateral Load Resisting System
Experimental Investigations
Seismic Performance
Research Status
Complete
Series
Journal of Asian Architecture and Building Engineering
Summary
Nine cyclic tests were conducted on full-scale one-story, one-bay timber post and beam construction specimens to study the lateral resistance of reinforced glued-laminated timber post and beam structures. Two reinforcement methods, wrapping fiber-reinforced polymer (FRP) and implanting self-tapping screws, and two structural systems, simple frame and knee-braced frame, were considered in the experimental tests. Based on the observed experimental phenomena and the test results, the feasibility of the reinforcement was discussed; the contributions of different methods were evaluated; and the seismic performance of the specimens were studied. The results indicated that both reinforcement methods could limit the crack development and improve the strength, stiffness and energy dissipation capacity. The results also showed that the lateral resistance could be significantly improved by retrofitting a failed simple frame with joint reinforcement and a knee-brace, demonstrating that this approach can be applied in engineering practice.
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The Heavy Timber Buckling-Restrained Braced Frame as a Solution for Commercial Buildings in Regions of High Seismicity

https://research.thinkwood.com/en/permalink/catalogue1651
Year of Publication
2016
Topic
Seismic
Design and Systems
Material
Solid-sawn Heavy Timber
Application
Wood Building Systems
Author
Blomgren, Hans-Erik
Koppitz, Jan-Peter
Díaz Valdés, Abel
Ko, Eric
Year of Publication
2016
Format
Conference Paper
Material
Solid-sawn Heavy Timber
Application
Wood Building Systems
Topic
Seismic
Design and Systems
Keywords
Lateral Load Resisting System
Mid-Rise
High-Rise
US
Building Codes
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3515-3524
Summary
Timber building construction has been traditionally utilized to reduce inertial demands in high seismic regions. Applications in the United States however, are often limited to low-rise buildings of light-wood construction with distributed load bearing shear walls. Recent advancements in timber technologies are pushing mass timber systems into larger commercial scale markets where steel and concrete systems dominate the landscape. In high seismic regions, mass timber buildings currently lack code-defined lateral force resisting systems. This paper presents a new lateral force resisting system concept, known as the Heavy Timber Buckling-Restrained Braced Frame. The system is conceived, although not limited, for application in mid and high-rise building timber construction, and is inspired by the unbonded steel brace technology today widely spread throughout Japan and the United States. In order to qualify the system for future implementation in building codes, the paper presents results from proof-of-concept component testing of a brace consisting of a steel core and a mechanically laminated glulam casing acting as the bucklingrestraint mechanism. As well, findings from a study for implementation at the building system level is provided in order to assess overall system performance, constructability, and detailing.
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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
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
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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Lateral Load Capacity in a Solid Structure Assembled with Glued-in Rods

https://research.thinkwood.com/en/permalink/catalogue2251
Topic
Connections
Application
Wood Building Systems
Organization
Université du Québec à Chicoutimi
Application
Wood Building Systems
Topic
Connections
Keywords
Glued-In Rods
Lateral Load
Lateral Load Resisting System
Research Status
In Progress
Notes
Project contact is Sylvain Ménard at Université du Québec à Chicoutimi
Summary
Assemblies with glued-in rods allow architectural freedom. They are in fact invisible since they are found in the mass of the structural element. Some work has begun to document this type of assembly by considering static tests in single-sided traction and single-sided creep tests (Verdet, 2016). In order to continue this effort to specify the limits of this type of assembly, it is proposed to consider the lateral forces for assemblies with single and multiple rod connections. This project will therefore aim to document the ability of these assemblies to carry lateral loads.
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Lateral Load Resisting Systems for Engineered Wood Construction

https://research.thinkwood.com/en/permalink/catalogue2637
Year of Publication
2009
Topic
Design and Systems
Wind
Seismic
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Author
Popovski, Marjan
Organization
FPInnovations
Year of Publication
2009
Format
Report
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Topic
Design and Systems
Wind
Seismic
Keywords
Lateral Load Resisting System
Construction
Research Status
Complete
Summary
The main sources of lateral loads on buildings are either strong winds or earthquakes. These lateral forces are resisted by the buildings’ Lateral Load Resisting Systems (LLRSs). Adequate design of these systems is of paramount importance for the structural behaviour in general. Basic procedures for design of buildings subjected to lateral loads are provided in national and international model building codes. Additional lateral load design provisions can be found in national and international material design standards. The seismic and wind design provisions for engineered wood structures in Canada need to be enhanced to be compatible with those available for other materials such as steel and concrete. Such design provisions are of vital importance for ensuring a competitive position of timber structures relative to reinforced concrete and steel structures. In this project a new design Section on Lateral Load Resisting Systems was drafted and prepared for future implementation in CSA O86, the Canadian Standard for Engineering Design in Wood. The new Section was prepared based on gathering existing research information on the behaviour of various structural systems used in engineered wood construction around the world as well as developing in-house research information by conducting experimental tests and analytical studies on structural systems subjected to lateral loads. This section for the first time tried to link the system behaviour to that of the connections in the system. Although the developed Section could not have been implemented in CSA O86 in its entirety during the latest code cycle that ended in 2008, the information it contains will form the foundation for future development of technical polls for implementation in the upcoming editions of CSA O86. Some parts of the developed Section were implemented in the 2009 edition of CSA O86 as five separate technical polls. The most important technical poll was the one on Special Seismic Design Considerations for Shearwalls and Diaphragms. This technical poll for the first time in North America includes partial capacity design procedures for wood buildings, and represents a significant step forward towards implementing full capacity-based seismic design procedures for wood structures. Implementation of these design procedures also eliminated most of the confusion and hurdles related to the design of wood-based diaphragms according to 2005 National Building Code of Canada. In other polls, the limit for use of unblocked shearwalls in CSA O86 was raised to 4.8 m, and based on the test results conducted during the project, the NLGA SPS3 fingerjoined studs were allowed to be used as substitutes for regular dimension lumber studs in shearwall applications in engineered buildings in Canada. With the US being the largest export market for the Canadian forest products industry, participation at code development committees in the field of structural and wood engineering in the US is of paramount importance. As a result of extensive activities during this project, for the first time one of the AF&PA Special Design Provisions for Wind and Seismic includes design values for unblocked shearwalls that were implemented based on FPInnovations’ research results. In addition, the project leader was involved in various aspects related to the NEESWood project in the US, in part of which a full scale six-storey wood-frame building will be tested at the E-Defense shake table in Miki, Japan in July 2009. Apart from being built from lumber and glued-laminated timber provided from Canada, the building will also feature the innovative Midply wood wall system that was also invented in Canada. The tests are expected to provide further technical evidence for increasing the height limits for platform frame construction in North America. Building construction - Design Earthquakes, Effect on building construction Glued joints - Finger Grading - Lumber Wind loads
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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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Performance Evaluation of Multi-Storey Cross-Laminated Timber Structures Under Different Earthquake Hazard Levels

https://research.thinkwood.com/en/permalink/catalogue1384
Year of Publication
2018
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Shear Walls
Author
Sun, Xiaofeng
He, Minjuan
Li, Zheng
Shu, Zhan
Publisher
Springer Japan
Year of Publication
2018
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Shear Walls
Topic
Design and Systems
Keywords
Equivalent Static Force Procedure
Multi-Storey
Seismic Performance
Lateral Load Resisting System
Inter-Story Drift
Pinching4 Model
Numerical Model
Probability of Non-Exceedance
Empirical Cumulative Distribution Functions
Research Status
Complete
Series
Journal of Wood Science
Summary
The inter-storey drift limitations are meaningful reference values for structural seismic performance evaluation. This paper presents an analytical investigation into the seismic performance of multi-storey cross-laminated timber (CLT) structures to obtain the drift limitations under different earthquake hazard levels reasonably. The Pinching4 model was used to simulate the nonlinear mechanical behavior of three types of connections used in CLT structures, and a numerical model was further developed to capture the lateral load-resisting properties of CLT shear walls. Moreover, three benchmark multi-storey CLT apartment buildings were designed using the Equivalent Static Force Procedure according to National Building Code of Canada (NBCC), and simplified structural models were developed for these buildings. Depending on the results from numerous time-history dynamic analyses, the empirical cumulative distribution functions (CDFs) of the maximum inter-storey drifts were constructed for the three benchmark buildings. The probability of non-exceedance (PNE) of inter-storey drift thresholds under different earthquake hazard levels was proposed and validated. It is recommended that for low-rise CLT buildings within three stories, values of 0.30%, 0.75%, and 1.40% can be considered as the drift limitations for frequent, medium, and rare seismic hazard levels, respectively. For mid-rise or high-rise buildings without three stories, 0.25%, 0.70%, and 1.30% can be considered as drift limitations.
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13 records – page 1 of 2.