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48 records – page 1 of 5.

Long Term Monitoring of Timber Bridges - Assessment and Results

https://research.thinkwood.com/en/permalink/catalogue2124
Year of Publication
2013
Topic
Moisture
Serviceability
Application
Bridges and Spans
Author
Franke, Bettina
Franke, Steffen
Müller, Andreas
Vogel, Mareike
Scharmacher, Florian
Tannert, Thomas
Publisher
Scientific Net
Year of Publication
2013
Format
Journal Article
Application
Bridges and Spans
Topic
Moisture
Serviceability
Keywords
Monitoring
Bridge
Moisture Content
Climate
Research Status
Complete
Series
Advanced Materials Research
Summary
Timber bridges have been built for decades all around the world. The hygroscopic material behavior of wood leads to the change of the moisture content of the wood and the dimensions depending on the climate. Therefore in regular inspections following questions arise: what happens with the wood due to the climate changes? Are there major changes of the moisture content? Are there differences between the natural material axes or within the cross section of the structural members? To answer these questions, traffic timber bridges with big cross sections are long-term monitored within a research project. The results of the moisture contents measured and a comparison between the different measuring groups and positions are presented. The analyses confirm that the moisture content in the wood follows the climate changes delayed and with smaller amplitude against the calculated equilibrium moisture content. In first steps, a different behavior of the change of the moisture content could be determined over the cross-section and along the span of the member.
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RILEM TC "Reinforcement of Timber Elements in Existing Structures"

https://research.thinkwood.com/en/permalink/catalogue433
Year of Publication
2013
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Author
Tannert, Thomas
Branco, Jorge
Riggio, Mariapaola
Publisher
Scientific.net
Year of Publication
2013
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Topic
Mechanical Properties
Keywords
Fiber Reinforced Polymer
Dovetail Joints
Reinforcement
Adhesive
Self-Tapping Screws
Strength
Stiffness
Bending Stiffness
Load Bearing Capacity
Research Status
Complete
Series
Advanced Materials Research
Summary
The paper reports on the activities of the RILEM technical committee “Reinforcement of Timber Elements in Existing Structures”. The main objective of the committee is to coordinate the efforts to improve the reinforcement practice of timber structural elements. Recent developments related to structural reinforcements can be grouped into three categories: (i) addition of new structural systems to support the existing structure; (ii) configuration of a composite system; and (iii) incorporation of elements to increase strength and stiffness. The paper specifically deals with research carried out at the Bern University of Applied Sciences Switzerland (BFH), the University of Minho Portugal (UniMinho), and the University of Trento Italy (UNITN). Research at BFH was devoted to improve the structural performance of rounded dovetail joints by means of different reinforcement methods: i) self-tapping screws, ii) adhesive layer, and iii) a combination of selftapping screws and adhesive layer. Research at UNITN targeted the use of “dry” connections for timber-to-timber composites, specifically reversible reinforcement techniques aimed at increasing the load-bearing capacity and the bending stiffness of existing timber floors. At UniMinho, double span continuous glulam slabs were strengthened with fibre-reinforced-polymers. All three examples demonstrate the improved structural performance of timber elements after reinforcing them.
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Experimental and Numerical Investigations of Fire Resistance of Novel Timber-Concrete-Composite Decks

https://research.thinkwood.com/en/permalink/catalogue891
Year of Publication
2013
Topic
Fire
Material
Timber-Concrete Composite
Application
Floors
Author
Meena, Rahul
Schollmayer, Martin
Tannert, Thomas
Publisher
American Society of Civil Engineers
Year of Publication
2013
Format
Journal Article
Material
Timber-Concrete Composite
Application
Floors
Topic
Fire
Keywords
Fire Resistance
Temperature
Research Status
Complete
Series
Journal of Performance of Constructed Facilities
Summary
A wood-concrete composite deck is presented, where wooden beams are placed in the compression side and the concrete layer is in the tension side. The main motive for this unusual setup is the better fire resistance of the system. The composite system was investigated under fire conditions. Experimental investigations were conducted on a small section of the structure in order to analyze the behaviour of the system. The specimen was subjected to the ISO-834 standard temperature-time curve with the concrete slab exposed to fire. Subsequently, the experiment was modeled using a commercial software package, and a transient thermal analysis was performed with temperature dependent material properties. The temperature profiles for all the materials are adequately comparable from both the investigations, i.e. experimental and numerical. The validated numerical model allows modifying geometrical parameters and determining fire-resistance ratings of different system configurations.
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Experimental and Numerical Investigation of Novel Steel-Timber-Hybrid System

https://research.thinkwood.com/en/permalink/catalogue81
Year of Publication
2014
Topic
Design and Systems
Seismic
Connections
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Bhat, Pooja
Azim, Riasat
Popovski, Marjan
Tannert, Thomas
Year of Publication
2014
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Seismic
Connections
Keywords
Tall Wood
Timber-Steel Hybrid
FFTT
Quasi-Static
Monotonic Testing
Cyclic Testing
Strong-column Weak-beam Failure
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
This paper summarises the experimental and numerical investigation conducted on the main connection of a novel steel-timber hybrid system called FFTT. The component behaviour of the hybrid system was investigated using quasi-static monotonic and reversed cyclic tests. Different steel profiles (wide flange I-sections and hollow rectangular sections) and embedment approaches for the steel profiles (partial and full embedment) were tested. The results demonstrated that when using an appropriate connection layout, the desired strong-column weak-beam failure mechanism was initiated and excessive wood crushing was avoided. A numerical model was developed that reasonably reflected the real component behaviour and can subsequently be used for numerical sensitivity studies and parameter optimization. The research presented herein serves as a precursor for providing design guidance for the FFTT system as an option for tall wood-hybrid buildings in seismic regions.
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Nonlinear Dynamic Analyses of Novel Timber-Steel Hybrid System

https://research.thinkwood.com/en/permalink/catalogue177
Year of Publication
2014
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Fairhurst, Michael
Zhang, Xiaoyue
Tannert, Thomas
Year of Publication
2014
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Seismic
Keywords
Ductility
FFTT
Finite Element Model
High-Rise
Multi-Storey
Timber-Steel Hybrid
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Although the benefits of using timber in mid- and high-rise construction are undisputed, there are perceived shortcomings with respect to the ductility needed to provide seismic resistance and a corresponding lack of appropriate design guidance. Overcoming these perceived shortcomings will allow timber, and its wood product derivatives, to further expand into the multi-storey construction sector, also in the context of hybrid structures that integrate different materials. The “Finding the Forest Through the Trees” (FFTT) system is a new hybrid system for high rise structures which combines the advantages of timber and steel as building materials. This paper presents research utilizing finite element models to capture the seismic response of the FFTT system and help developing design guidance. From the results presented herein, it appears that the FFTT system can meet the design performance requirements required for seismic loading: inter-storey drifts were lower than required and local plastic deformations were within a reasonable range for life safety performance.
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Long-Term Performance of Adhesively Bonded Timber-Concrete-Composites

https://research.thinkwood.com/en/permalink/catalogue390
Year of Publication
2014
Topic
Connections
Mechanical Properties
Serviceability
Material
Timber-Concrete Composite
Application
Beams
Author
Tannert, Thomas
Brunner, Maurice
Vallée, Till
Endacott, Bryn
Year of Publication
2014
Format
Conference Paper
Material
Timber-Concrete Composite
Application
Beams
Topic
Connections
Mechanical Properties
Serviceability
Keywords
Adhesives
Long-term
Deflection
Environmental Conditions
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Timber-concrete-composite (TCC) floors are a successful example of hybrid structural components. TCC are composed of timber and concrete layers connected by a shear connector and are commonly used in practical civil engineering applications. The connection of the two components is usually achieved with mechanical fasteners where relative slip cannot be prevented and the connection cannot be considered rigid. More recently, an adhesively bonded TCC system has been proposed, and has been shown to perform predictably under static short-term loading. One of the main considerations when designing TCC floors is their long-term performance. In the research presented herein, two adhesively bonded TCC beams were exposed to serviceability loads for approximately 4.5 years. During this time the environmental conditions and the deflections were monitored. After having been loaded for 4.5 years, the beams were tested to failure, resulting in findings that long-term loading caused no degradation of the adhesive bond. This research provides input data to develop design guidance for adhesively bonded TCC under long-term loading.
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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
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
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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Shell Structures in Wood

https://research.thinkwood.com/en/permalink/catalogue19
Year of Publication
2015
Topic
Market and Adoption
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Shell Structures
Author
Cheng, Alexandra
Meyboom, AnnaLisa
Hunter, Jessica
Neumann, Oliver
Cloutier, Roy
Maia, Sara
Gaudin, Thomas
Tannert, Thomas
Organization
University of British Columbia
Year of Publication
2015
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Shell Structures
Topic
Market and Adoption
Design and Systems
Keywords
Design
Research Status
Complete
Summary
The larger intention of this research and the future research trajectory is to expand the conception of wood as a structural building material, encouraging its broader use both within Canada and in emerging markets. When architects and engineers desire a curved surface they should think of wood as the material that can create these new architectural forms. Shell, lapped, and folded plate structures using CLT show potential for spanning larger interior spaces such as those in gymnasiums, community centres, schools, churches general large entry spaces and circulation areas. They provide large column free spans, and are highly structurally efficient.
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Seismic Reliability Analyses of Timber-Steel-Hybrid System

https://research.thinkwood.com/en/permalink/catalogue121
Year of Publication
2015
Topic
Design and Systems
Seismic
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Zhang, Xiaoyue
Fairhurst, Michael
Tannert, Thomas
Year of Publication
2015
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Seismic
Keywords
Connections
non-lineardynamic analysis
Lateral Loads
Timber-Steel Hybrid
FFTT
Conference
International Conference on Applications of Statistics and Probability in Civil Engineering
Research Status
Complete
Notes
July 12-15, 2015, Vancouver, Canada
Summary
Reliability analyses are of great importance in performance-based seismic structural design as there are inherent uncertainties in both the actions (earthquakes) and the reactions (properties of the structural systems). In this paper, reliability analyses are performed on the “Finding the Forest Through the Trees” (FFTT) system, a novel timber-steel hybrid system. The FFTT system utilizes engineered timber products to resist gravity and lateral loads with interconnecting steel members to provide the necessary ductility for seismic demands. An improved response surface method with importance sampling is used to perform reliability-based seismic analyses. Peak inter-storey drift is selected as the main performance criterion as it is typically an indicator of overall damage to the structure. Uncertainties involving ground motions, weight (mass), stiffness and connection properties of the lateral load resisting\ system are considered in formulating the performance functions. A series of nonlinear dynamic analyses is run to generate the response database and the reliability index is evaluated using first-order reliability method (FORM) and importance sampling (IS) methods. The results show that the ductility reduction factor does not significantly influence the reliability index, while the structural weight and the hold-down stiffness play significant roles.
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Timber Shell: Wood in Building

https://research.thinkwood.com/en/permalink/catalogue264
Year of Publication
2015
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Shell Structures
Author
Neumann, Oliver
Hunter, Jessica
Meyboom, AnnaLisa
Cheng, Alex
Tannert, Thomas
Publisher
American Research Institute for Policy Development
Year of Publication
2015
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Shell Structures
Topic
Design and Systems
Keywords
Prototype
Research Status
Complete
Series
Journal of Engineering and Architecture
Summary
Contemporary design technology has given architects the ability to imagine and visualize complex structures to an extent that is currently beyond our ability to effectively fabricate and build. The described research is intended to mediate between the imagination of the designer and the current modes of construction; this project is part of a larger proposition to use wood as a sustainably sourced material that can be formed, curved and machined to create new digitally produced and tested formations. TimberShell creates prototypes for full-scale timber monocoque structures. Material computation affords us the ability to use the natural bending properties of wood to both bend components into shape and to create a robust load carrying structure once individual wood components are locked in by lamination. The geometry of the shell panel eliminates twisting. The research shows how doubly-curved timber shells that can be applied in either tension or compression. The panels can be used to create and cover spanning structures such as pools, gyms and auditoriums.
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48 records – page 1 of 5.