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15 records – page 1 of 2.

An Equivalent Truss Method for the Analysis of Timber Diaphragms

https://research.thinkwood.com/en/permalink/catalogue112
Year of Publication
2015
Topic
Design and Systems
Mechanical Properties
Material
Light Frame (Lumber+Panels)
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
Glulam (Glue-Laminated Timber)
Application
Floors
Author
Moroder, Daniel
Smith, Tobias
Pampanin, Stefano
Buchanan, Andrew
Year of Publication
2015
Country of Publication
Australia
Format
Conference Paper
Material
Light Frame (Lumber+Panels)
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
Glulam (Glue-Laminated Timber)
Application
Floors
Topic
Design and Systems
Mechanical Properties
Keywords
Diaphragms
Equivalent Truss Method
Fasteners
Forces
Deflection
Torsion
Language
English
Conference
Pacific Conference on Earthquake Engineering
Research Status
Complete
Notes
November 6-8, 2015, Sydney, Australia
Summary
Recent years have seen more architects and clients asking for tall timber buildings. In response, an ambitious timber community has been proposing challenging plans and ideas for multi-storey commercial and residential timber buildings. While engineers have been intensively looking at gravity-load-carrying elements as well as walls, frames and cores to resist lateral loads, floor diaphragms have been largely neglected. Complex floor geometries and long span floor diaphragms create stress concentrations, high force demand and potentially large deformations. There is a lack of guidance and regulation regarding the analysis and design of timber diaphragms so structural engineers need a practical alternative to simplistic equivalent deep beam analysis or costly finite element modelling. This paper proposes an equivalent truss method capable of solving complex geometries for both light timber framing and massive timber diaphragms. Floor panels are discretized by equivalent diagonals, having the same stiffness as the panel including its fasteners. With this method the panel unit shear forces (shear flow) and therefore fastener demand, chord forces and reaction forces can be evaluated. Because panel stiffness is accounted for, diaphragm deflection, torsional effects and transfer forces can also be assessed.
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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
Country of Publication
New Zealand
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
Language
English
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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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
Country of Publication
Austria
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
Language
English
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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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

Dynamic Testing of Multi-Storey Post-Tensioned Glulam Building: Planning, Design and Numerical Analysis

https://research.thinkwood.com/en/permalink/catalogue634
Year of Publication
2012
Topic
Design and Systems
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Smith, Tobias
Pampanin, Stefano
Carradine, David
Di Cesare, Antonio
Carlo Ponzo, Felice
Auletta, Gianluca
Nigro, Domenico
Simonetti, Michele
Mossucca, Antonello
Year of Publication
2012
Country of Publication
Portugal
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Keywords
Post-Tensioned
Dissipative Steel Angles
Dynamic Testing
Damping Ratio
Language
English
Conference
World Conference on Earthquake Engineering
Research Status
Complete
Notes
September 24-28, 2012, Lisbon, Portugal
Summary
The following paper describes the first stage of dynamic testing of a post-tensioned timber building to be performed in the structural laboratory of the University of Basilicata in Potenza, Italy as part of a series of experimental tests in collaboration with the University of Canterbury in Christchurch, New Zealand. During this stage of testing a 3-dimensional, 3-storey post-tensioned timber structure will be tested. The specimen is 2/3rd scale and made up of frames in both directions composed of post-tensioned timber. The specimen will be tested both with and without the addition of dissipative steel angles which are designed to yield at a certain level drift. These steel angles release energy through hysteresis during movement thus increasing damping. The following paper discusses the testing set-up and preliminary numerical predictions of the system performance. Focus will be placed on damping ratios, displacements and accelerations.
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Experimental Behaviour of Diaphragms in Post-Tensioned Timber Frame Buildings

https://research.thinkwood.com/en/permalink/catalogue95
Year of Publication
2014
Topic
Connections
Seismic
Material
LVL (Laminated Veneer Lumber)
Application
Floors
Author
Moroder, Daniel
Smith, Tobias
Simonetti, Michele
Carlo Ponzo, Felice
Di Cesare, Antonio
Nigro, Domenico
Pampanin, Stefano
Buchanan, Andrew
Organization
The European Association for Earthquake Engineering
Year of Publication
2014
Country of Publication
Turkey
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Application
Floors
Topic
Connections
Seismic
Keywords
Diaphragms
Lateral Loads
Post-Tensioning
Shake Table Test
Testing
Language
English
Conference
Second European Conference on Earthquake Engineering and Seismology
Research Status
Complete
Notes
August 25-29, 2014, Istanbul, Turkey
Summary
Floor diaphragms have an important role in the seismic behaviour of structures, as inertia forces are generated by their masses and then transferred to the lateral load resisting system. Diaphragms also link all other structural elements together and provide general stability to the structure. As with most other structural components, there is concern about damage to floor diaphragms because of displacement incompatibilities. This paper describes two different experiments on engineered timber floors connected to post-tensioned timber frames subjected to horizontal loading. First a full scale two-bay post-tensioned frame was loaded with lateral loads through a stressed-skin floor diaphragm. Different connection configurations between the floor units on either side of the central column were tested. Secondly a three dimensional, three storey post-tensioned frame building was tested on a shaking table. The diaphragm consisted of solid timber panels connected to the beams with inclined fully threaded screws. For all tested connections, the diaphragm behaviour was fully maintained throughout the testing and no damage was observed. The test results showed that careful detailing of the floor panel connections near the beam-columnjoint and the flexibility of timber elements can avoid floor damage and still guarantee diaphragm action at high level of drifts in post-tensioned timber frame buildings.
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Higher Mode Effects in Multi-Storey Timber Buildings with Varying Diaphragm Flexibility

https://research.thinkwood.com/en/permalink/catalogue1480
Year of Publication
2017
Topic
Seismic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Frames
Walls
Author
Moroder, Daniel
Sarti, Francesco
Pampanin, Stefano
Smith, Tobias
Buchanan, Andrew
Year of Publication
2017
Country of Publication
New Zealand
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Frames
Walls
Topic
Seismic
Mechanical Properties
Keywords
Nonlinear Time History Analysis
Higher Mode Effects
Stiffness
Diaphragms
Inter-Story Drift
Language
English
Conference
New Zealand Society for Earthquake Engineering Conference
Research Status
Complete
Notes
April 27-29, 2017, Wellington, New Zealand
Summary
With the increasing acceptance and popularity of multi-storey timber buildings up to 10 storeys and beyond, the influence of higher mode effects and diaphragm stiffness cannot be overlooked in design. Due to the lower stiffness of timber lateral load resisting systems compared with traditional construction materials, the effect of higher modes on the global dynamic behaviour can be more critical. The presence of flexible timber diaphragms creates additional vibration modes, which have the potential to interact with each other, increasing the seismic demand on the whole structure. This paper uses a parametric non-linear time-history analysis on a series of timber frame and wall structures with varying diaphragm flexibility to study their dynamic behaviour and to determine diaphragm forces. The analyses results showed that although higher mode effects play a significant role in the structural dynamic response, this increased demand can be successfully predicted with methods available in literature. The parametric analyses showed that the diaphragm flexibility did not significantly increase the shear and moment demand; however, stiff wall structures with flexible diaphragms experienced large inter-storey drifts measured at diaphragm midspan compared with the drift of the wall alone. As expected, the diaphragm forces observed from the time-history analyses were significantly higher than the forces derived from an equivalent static analysis, leading to a potentially unsafe design. The paper presents a simplified approach for evaluating these amplified peak inertial diaphragm forces.
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Long-term Dynamic Characteristics of Pres-Lam Structures

https://research.thinkwood.com/en/permalink/catalogue1647
Year of Publication
2016
Topic
Design and Systems
Seismic
Material
LVL (Laminated Veneer Lumber)
Application
Wood Building Systems
Author
Smith, Tobias
Sarti, Francesco
Granello, Gabriele
Marshall, Jack
Buckton-Wishart, Victoria
Li, Minghao
Palermo, Alessandro
Pampanin, Stefano
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Application
Wood Building Systems
Topic
Design and Systems
Seismic
Keywords
Pres-Lam
Long-term
Dynamic Behaviour
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3462-3470
Summary
Pres-Lam timber structures are being adopted throughout New Zealand and around the world. This innovative method of timber construction combines the use of large engineered timber members with posttensioning cables/bars. The hybrid version of the Pres-Lam system improves seismic performance through the addition of external or internal steel reinforcing. While the post-tensioning provides re-centering properties, the steel increases energy dissipation from the system as well as increasing moment resistance. The design of these structures is performed to withstand high levels of seismic loading without damage to the structural system. Over time, the post-tensioning force being applied to the structural timber members causes them to reduce in length that has a subsequent impact on the quantity of force being applied. This paper looks at the dynamic characteristics of fundamental period and elastic damping of three recently constructed Pres-Lam buildings, investigating the influence of these losses on the dynamic characteristics. Following this a study of the performance under strong motion is performed. The paper concludes that although the losses in post-tensioning are clear they do not impact on the dynamic characteristics and have only a minor impact on strong motion response.
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Non-Linear Numerical Modelling of a Post-Tensioned Timber Frame Building with Dissipative Steel Angle Devices

https://research.thinkwood.com/en/permalink/catalogue649
Year of Publication
2014
Topic
Seismic
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Simonetti, Michele
Smith, Tobias
Carlo Ponzo, Felice
Di Cesare, Antonio
Pampanin, Stefano
Nigro, Domenico
Year of Publication
2014
Country of Publication
Turkey
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Keywords
Numerical modelling
Pres-Lam
Non-linear Dynamic Loading
Static Loading
Beam-Column Joint
Dissipative Steel Angles
Language
English
Conference
European Conference on Earthquake Engineering and Seismology
Research Status
Complete
Notes
August 25-29, 2014, Istanbul, Turkey
Summary
This paper describes the numerical modelling of post-tensioned timber (Pres-Lam) frame systems under non-linear dynamic and static loading. From the conception of the post-tensioned jointed ductile concept it has been clear that the nature of its controlled rocking mechanism leant itself well to the use of a lumped plasticity approach. This approach combines the use of elastic elements with springs representing plastic rotations in the system. Two experimental testing campaigns have been used in order to confirm the effectiveness of this modelling technique in predicting both the global (frame) and local (beam-column) response of these systems. The first of these tests was a full scale beam-column joint tested quasi-statically and the second was a 3-dimensional, 3-storey, 2/3rd scale multi-storey post-tensioned timber frame building tested dynamically. During the testing programmes the specimens were tested both with and without the addition of dissipative steel angles which were designed to yield at a certain level of drift. These steel angles release energy through hysteresis during lateral frame movement thus increasing damping. Both structures were modelled using a lumped plasticity approach with springs that were calibrated against the moment rotation design procedure used for post-tensioned timber connections. This work has proved the adequacy of the use of two numerical modelling programs, RUAUMOKO and SAP2000, in providing accurate representation of structural response when calibrated against current design procedures. All testing was performed in the structural laboratory of the University of Basilicata in Potenza, Italy. This experimental campaign is part of a series of experimental tests in collaboration with the University of Canterbury, Christchurch, New Zealand.
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Free
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Non-Linear Numerical Modelling of a Post-Tensioned Timber Frame Building with Hysteretic Energy Dissipation

https://research.thinkwood.com/en/permalink/catalogue532
Year of Publication
2014
Topic
Seismic
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Smith, Tobias
Di Cesare, Antonio
Carlo Ponzo, Felice
Simonetti, Michele
Nigro, Domenico
Pampanin, Stefano
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Keywords
Post-Tensioned
Pres-Lam
Shake Table Test
Energy Dissipation
Dynamic Behaviour
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
The following paper describes the numerical modelling used to predict the dynamic behaviour of a posttensioned timber building with the addition of a hysteretic energy dissipation system. This modelling is in support of a shaking table test programme performed on a 2/3rd scale, 3-dimensional, 3-storey structure made from post-tensioned timber frames in both directions. Testing was carried out in the structural laboratory of the University of Basilicata in Potenza, Italy as part of a collaborative project between the University and the University of Canterbury in Christchurch, New Zealand. Modelling used two non-linear finite element codes, SAP2000 and RUAUMOKO. This paper compares numerical results obtained from the model with and without additional dissipative elements in order to better understand the dynamic behaviour of post-tensioned timber structures. Comparison is made with the results of the experimental campaign and amongst the finite element programs themselves.
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Free
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15 records – page 1 of 2.