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36 records – page 2 of 4.

Experimental Investigation of Connection for the FFTT, A Timber-Steel Hybrid System

https://research.thinkwood.com/en/permalink/catalogue269
Year of Publication
2013
Topic
Connections
Design and Systems
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Author
Bhat, Pooja
Organization
University of British Columbia
Year of Publication
2013
Country of Publication
Canada
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Topic
Connections
Design and Systems
Mechanical Properties
Keywords
FFTT
Quasi-Static
Monotonic Testing
Reverse Cyclic Testing
Embedment Depth
Embedment Length
Strong-column Weak-beam Failure
Cross-Section Reduction
Language
English
Research Status
Complete
Summary
This thesis fills the existing knowledge gap between detailed design and global behaviour of hybrid systems through an experimental study on an innovative timber-steel hybrid system called “FFTT”. The FFTT system relies on wall panels of mass timber such as CLT for gravity and lateral load resistance and embedded steel sections for ductility under the earthquake loads. An important step towards the practical application of the FFTT system is obtaining the proof that the connections facilitate the desired ductile failure mode. The experimental investigation was carried out at the facility of FPInnovations, Vancouver. The testing program consisted of quasi-static monotonic and reverse cyclic tests on the timber-steel hybrid system with different configurations. The two beam profiles, wide flange I-sections and hollow rectangular sections were tested. The interaction between the steel beams and CLT panels and the effect of the embedment depth, cross-section reduction and embedment length were closely examined. The study demonstrated that when using an appropriate steel section, the desired ‘Strong Column–Weak Beam’ failure mechanism was initiated and excessive wood crushing was avoided. While wide-flange I-sections were stiffer and stronger, the hollow sections displayed better post-yield behaviour with higher energy dissipation capacity through several cycles of deformation under cyclic loads. The out-of-plane buckling at the point of yielding was the major setback of the embedment of wide-flange I-sections. This research served as a precursor for providing design guidance for the FFTT system as one option for tall wood buildings in high seismic regions.
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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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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
Country of Publication
Austria
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
Language
English
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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High Performance Cross-Laminated-Timber Shear Connection with Self-Tapping Screw Assemblies

https://research.thinkwood.com/en/permalink/catalogue504
Year of Publication
2014
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Danzig, Ilana
Closen, Maximilian
Tannert, Thomas
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Connections
Mechanical Properties
Keywords
Self-Tapping Screws
Panels
Full Scale
Quasi-Static
Reverse Cyclic Loading
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
The research presented in this paper examines the performance of a shear connection using self-tapping screws (STS) in 3-ply Cross-Laminated Timber (CLT) panels. CLT panels were connected with STS assemblies at an inclined angle in two directions. The capacity of the STS assemblies was tested for the purpose of designing a CLT roof diaphragm of a large storage facility where a high-performance and low-manufacturing-cost solution was required. A total of eleven full-scale specimens were subjected to quasi-static and reversed-cyclic shear loading. Resulting forcedisplacement and hysteretic curves were used to determine an equivalent energy elastic-plastic curve based on ASTM E2126-11 procedures to estimate assembly yield strength, yield displacement, and ductility ratio. The performance in terms of strength and stiffness was excellent, and the STS provided the required ductility for the system to be used in seismic applications. Static yield strength averaged 80kN/m with an average ductility ratio of 7.7 while cyclic yield strength averaged 68kN/m with an average ductility ratio of 4.1. The data obtained allows engineers to specify low-cost lateral load resisting connection systems for large scale CLT structures.
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Lateral Load Resistance of Cross-Laminated Wood Panels

https://research.thinkwood.com/en/permalink/catalogue2150
Year of Publication
2010
Topic
Connections
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Walls

Numerical and Experimental Investigations of Connection for Timber-Steel Hybrid System

https://research.thinkwood.com/en/permalink/catalogue213
Year of Publication
2014
Topic
Connections
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Azim, Riasat
Organization
University of British Columbia
Year of Publication
2014
Country of Publication
Canada
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Connections
Design and Systems
Keywords
FFTT
Mid-Rise
Timber-Steel Hybrid
Quasi-Static
Monotonic Testing
Reverse Cyclic Testing
Language
English
Research Status
Complete
Summary
In recent years, hybrid systems have grown in popularity as potential solution for mid-rise construction. There is also an increased interest in using timber for such systems. The lack of established design guidance, however, has tabled the practical implementation of timber-based hybrid structures. The aim of this thesis is to address the existing knowledge gap regarding the detailed connection design of hybrid systems through combined experimental and numerical investigations on a novel timber-steel system called “FFTT”. The FFTT system relies on wall panels of mass timber such as Cross-Laminated-Timber (CLT) for gravity and lateral load resistance and embedded steel beam sections to provide ductility under seismic loading. A vital step towards practical implementation of the FFTT system is to obtain the proof that the connections facilitate the desired ‘strong column – weak beam’ failure mechanism. The numerical work applied the software ANSYS; a parametric study based on the results of previous tests was conducted to obtain a suitable connection configuration for improved structural performance. The experimental work, carried out at FPInnovations, consisted of quasi-static monotonic and reversed cyclic tests on two different connection configurations: fully and partially embedded ASTM wide flange sections in combination with 7 ply CLT panels. The combination of partial embedment length and full embedment depth, even when using the smallest wide flange section, did not facilitate the desired behavior. The connection performance was significantly improved when reducing the embedment depth (to avoid creating stress peaks on a weak cross layer) and increasing the embedment length (larger center to center distance between bearing plates). The used small size steel beam, however, is not practical for a real structure; therefore, further studies with larger beams and a modified geometry are recommended before the FFTT system can be applied in practice.
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Performance and Design of LVL Walls Coupled with UFP Dissipaters

https://research.thinkwood.com/en/permalink/catalogue195
Year of Publication
2014
Topic
Seismic
Material
LVL (Laminated Veneer Lumber)
Application
Shear Walls
Author
Iqbal, Asif
Pampanin, Stefano
Palermo, Alessandro
Buchanan, Andrew
Publisher
Taylor&Francis Online
Year of Publication
2014
Country of Publication
United Kingdom
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
Application
Shear Walls
Topic
Seismic
Keywords
Cyclic
Energy Dissipation
Multi-Storey
Post-Tensioned
U-Shaped Flexural Plates
Quasi-Static
Pseudo-dynamic
Language
English
Research Status
Complete
Series
Journal of Earthquake Engineering
Notes
http://dx.doi.org/10.1080/13632469.2014.987406
Summary
This article presents recent research on the seismic resistance of coupled post-tensioned timber walls for use in multi-story buildings. The walls are constructed from laminated veneer lumber (LVL), post-tensioned with unbonded vertical tendons, and coupled together with mild steel U-shaped flexural plates (UFPs) as energy dissipating elements. The timber wall design follows the same principles as used for post-tensioned precast concrete wall systems, using U-shaped plates to obtain a “hybrid” system, where energy is dissipated through yielding of the plates, while the vertical post-tensioning provides the restoring force. In this project, the same principles are applied to timber coupled walls. A series of quasi-static cyclic and pseudo-dynamic tests have been carried out to verify the applicability of the concept and the feasibility of the construction technology in timber buildings. The U-shaped plates showed stable energy dissipation characteristics and, in combination with the post-tensioning, desirable re-centering hysteretic behavior typically referred to as “flag-shape”. Because of the simplicity of these elements and the low cost of implementation, they have good prospects for practical application.
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Performance Based Design and Force Modification Factors for CLT Structures

https://research.thinkwood.com/en/permalink/catalogue928
Year of Publication
2012
Topic
Seismic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Walls
Author
Pei, Shiling
Popovski, Marjan
van de Lindt, John
Year of Publication
2012
Country of Publication
Sweden
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Walls
Topic
Seismic
Design and Systems
Keywords
Quasi-Static Tests
R-factors
Performance-Based Seismic Design
US
Canada
Language
English
Conference
CIB-W18 Meeting
Research Status
Complete
Notes
August 27-30, 2012, Växjö, Sweden p.293-304
Summary
In this paper, a performance-based seismic design (PBSD) of a CLT building was conducted and the seismic response of the CLT building was compared to that of a wood-frame structure tested during the NEESWood project. The results from the quasi-static tests on CLT walls performed at FPInnovations were used as input information for modelling of the CLT walls, the main lateral load resisting elements of the structure. Once the satisfactory design of the CLT mid-rise structure was established through PBSD, a force-based design was developed with varying R-factors and that design was compared to the PBSD result. In this way, suitable R-factors were calibrated so that they can yield equivalent seismic performance of the CLT building when designed using the traditional force-based design methods. Based on the results of this study it is recommended that a value of Rd=2.5 and Ro=1.5 can be assigned for structures with symmetrical floor plans in the National Building Code of Canada (NBCC). In the US an R=4.3 can be used for symmetrical CLT structures designed according to ASCE 7. These values can be assigned provided that the design values for CLT walls considered (and implemented in the material design standards) are similar to the values determined in this study using the kinematics model developed that includes the influence of the hold-downs in the CLT wall resistance. Design of the CLT building with those R-factors using the equivalent static procedures in the US and Canada will result in the CLT building having similar seismic performance to that of the tested wood-frame NEESWood building, which had only minor non-structural damage during a rare earthquake event.
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Performance of Timber-Concrete Composite Floors Using Flat-Plate Engineered Wood Products

https://research.thinkwood.com/en/permalink/catalogue1618
Year of Publication
2016
Topic
Mechanical Properties
Material
Timber-Concrete Composite
CLT (Cross-Laminated Timber)
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
Application
Floors
Author
Gerber, Adam
Popovski, Marjan
Tannert, Thomas
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Timber-Concrete Composite
CLT (Cross-Laminated Timber)
LSL (Laminated Strand Lumber)
LVL (Laminated Veneer Lumber)
Application
Floors
Topic
Mechanical Properties
Keywords
Strength
Stiffness
Small Scale
Shear Tests
Elastic Stiffness
Quasi-Static
Loading
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2397-2406
Summary
Timber-Concrete Composite (TCC) systems are comprised of a timber element connected to a concrete slab through a mechanical shear connection. A large number of T-beam configurations currently exist; however, the growing availability of panel-type engineered wood products (EWPs) in North America in combination with a concrete topping has offered designers and engineers greater versatility in terms of architectural expression and structural and building physics performance. The focus of this investigation was to experimentally determine the properties for a range of TCC systems in several EWPs. Strength and stiffness properties were determined for different TCC configurations based on small-scale shear tests. Eighteen floor panels were tested for elastic stiffness under a quasi-static loading protocol and measurements of the dynamic properties were obtained prior to loading to failure. The tests confirmed that calculations according to the -method can predict the basic stiffness and dynamic properties of TCC floors within a reasonable degree of accuracy. Floor capacities were more difficult to predict, however, failure occurred at loads that were between four and ten times serviceability requirements. The research demonstrated that all selected connector configurations produced efficient timber-concrete-composite systems.
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Performance of Two-Storey CLT House Subjected to Lateral Loads

https://research.thinkwood.com/en/permalink/catalogue376
Year of Publication
2014
Topic
Connections
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Popovski, Marjan
Gavric, Igor
Schneider, Johannes
Organization
FPInnovations
Year of Publication
2014
Country of Publication
Canada
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Connections
Design and Systems
Keywords
Lateral Loads
North America
Building Codes
Full Scale
Quasi-Static
Monotonic Loading
Cyclic Loading
Failure Mechanism
Language
English
Research Status
Complete
Summary
The work presented in this report is a continuation of the FPInnovations' research project on determining the performance of the CLT as a structural system under lateral loads. A two storey full-scale model of a CLT house was tested under quasi-static monotonic and cyclic lateral loading in two directions, one direction at a time. In total five tests were performed; one push-over and two cyclic tests were conducted in the longer symmetrical direction (E-W), and two cyclic tests were performed in the shorter asymmetrical direction (N-S). In addition, before and after each test, natural frequencies of the house in both directions were measured. The main objective of the tests was to investigate 3-D system behaviour of the CLT structure subjected to lateral loads. The CLT structure subjected to lateral loads performed according to the design objectives.
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36 records – page 2 of 4.