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11 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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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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Experimental Investigation of Wall-To-Floor Connections in Post-Tensioned Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue60
Year of Publication
2014
Topic
Connections
Seismic
Material
LVL (Laminated Veneer Lumber)
Application
Walls
Floors
Author
Moroder, Daniel
Sarti, Francesco
Palermo, Alessandro
Pampanin, Stefano
Buchanan, Andrew
Year of Publication
2014
Country of Publication
New Zealand
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Application
Walls
Floors
Topic
Connections
Seismic
Keywords
Connections
Damage
Lateral Loads
Post-Tensioned
Pres-Lam
Language
English
Conference
New Zealand Society for Earthquake Engineering Conference
Research Status
Complete
Notes
March 21-23, 2014, Auckland, New Zealand
Summary
Rocking timber walls provide an excellent lateral load resisting system for structures using the low damage seismic design philosophy. Special attention has to be given to the wall-to-floor connections, because diaphragm forces have to be properly transferred while accommodating displacement incompatibilities, which include the relative rotation and the uplift of the wall with respect to the floor. This paper presents the experimental behaviour of several different wall-to-floor connections in Pres-Lam post-tensioned timber structures subjected to horizontal seismic loading. A 2/3 scale post-tensioned timber wall was laterally loaded through collector beams using different connection details. Bolted connections take advantage of the flexibility of the fasteners and lead to some bending of the collector beam, whereas pins and slotted steel plates reduce the wall-tofloor interaction, as they allow for rotation and some uplift. No significant damage to the floors was observed in any of the tests. The experimental results showed that floor damage can generally be prevented up to high levels of drift by the flexibility of well-designed connections and the flexibility of the collector beams. In the case of very stiff floors or very stiff collector beams, a more sophisticated connection such as sliding steel elements with a vertical slot should be considered.
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Floor Diaphragms in Multi-Storey Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue71
Year of Publication
2016
Topic
Design and Systems
Seismic
Material
Light Frame (Lumber+Panels)
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
CLT (Cross-Laminated Timber)
Application
Floors
Author
Moroder, Daniel
Organization
University of Canterbury
Year of Publication
2016
Country of Publication
New Zealand
Format
Thesis
Material
Light Frame (Lumber+Panels)
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Design and Systems
Seismic
Keywords
Diaphragms
Lateral Loads
Multi-Storey
Equivalent Truss Method
Pres-Lam
Language
English
Research Status
Complete
Summary
This thesis studies the behaviour of diaphragms in multi-storey timber buildings by providing methods for the estimation of the diaphragm force demand, developing an Equivalent Truss Method for the analysis of timber diaphragms, and experimentally investigating the effects of displacement incompatibilities between the diaphragm and the lateral load resisting system and developing methods for their mitigation. Although shortcomings in the estimation of force demand, and in the analysis and design of concrete floor diaphragms have already been partially addressed by other researchers, the behaviour of diaphragms in modern multi-storey timber buildings in general, and in low damage Pres-Lam buildings (consisting of post-tensioned timber members) in particular is still unknown. The analysis of light timber framing and massive timber diaphragms can be successfully analysed with an Equivalent Truss Method, which is calibrated by accounting for the panel shear and fastener stiffnesses. Finally, displacement incompatibilities in frame and wall structures can be accommodated by the flexibilities of the diaphragm panels and relative connections. A design recommendations chapter summarizes all findings and allows a designer to estimate diaphragm forces, to analyse the force path in timber diaphragms and to detail the connections to allow for displacement incompatibilities in multi-storey timber 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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Preventing Seismic Damage to Floors in Post-Tensioned Timber Frame Buildings

https://research.thinkwood.com/en/permalink/catalogue1851
Year of Publication
2018
Topic
Design and Systems
Seismic
Material
LVL (Laminated Veneer Lumber)
Application
Columns
Beams
Frames
Floors
Author
Moroder, Daniel
Buchanan, Andrew
Pampanin, Stefano
Publisher
New Zealand Timber Design Society
Year of Publication
2018
Country of Publication
New Zealand
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
Application
Columns
Beams
Frames
Floors
Topic
Design and Systems
Seismic
Keywords
Beam-to-Column Joints
Connections
Horizontal Loading
Post-Tensioned
Earthquake
Language
English
Research Status
Complete
Series
New Zealand Timber Design Journal
Online Access
Free
Resource Link
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Seismic Design of Cross-Laminated Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue1971
Year of Publication
2018
Topic
Seismic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Tannert, Thomas
Follesa, Maurizio
Fragiacomo, Massimo
González Soto, Paulina
Isoda, Hiroshi
Moroder, Daniel
Xiong, Haibei
van de Lindt, John
Publisher
Society of Wood Science and Technology
Year of Publication
2018
Country of Publication
United States
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Design and Systems
Keywords
Seismicity
Design Standards
Platform-Type Construction
Ductility
Connections
Language
English
Research Status
Complete
Series
Wood and Fiber Science
Summary
The increasing interest in cross-laminated timber (CLT) construction has resulted in multiple international research projects and publications covering the manufacturing and performance of CLT. Multiple regions and countries have adopted provisions for CLT into their engineering design standards and building regulations. Designing and building CLT structures, also in earthquake-prone regions is no longer a domain for early adopters, but is becoming a part of regular timber engineering practice...
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Seismic Design of Floor Diaphragms in Post-Tensioned Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue507
Year of Publication
2014
Topic
Design and Systems
Seismic
Material
LVL (Laminated Veneer Lumber)
Application
Walls
Floors
Author
Moroder, Daniel
Sarti, Francesco
Palermo, Alessandro
Pampanin, Stefano
Buchanan, Andrew
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Application
Walls
Floors
Topic
Design and Systems
Seismic
Keywords
Post-Tensioned
Frame Elongation
Rocking
Diaphragm
Lateral Load Resisting System
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Seismic damage to floor diaphragms because of displacement incompatibilities are a point of concern in many structures. This paper studies the behaviour of timber diaphragms subjected to frame elongation and rocking of walls in post-tensioned timber buildings. Experimental tests with special connection details between floor panels and between the diaphragm and the lateral load resisting system show that floor damage in severe earthquakes can be avoided by designing for flexibility and proper connection detailing
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Simplified Analytical Models for Coupled CLT Walls

https://research.thinkwood.com/en/permalink/catalogue1727
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Sandoli, Antonio
Moroder, Daniel
Pampanin, Stefano
Calderoni, Bruno
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Mechanical Properties
Keywords
Coupling
Stiffness
Model
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4681-4690
Summary
The use of coupled CLT walls in the field of timber building is strongly increasing, thanks especially their easiness of construction and transportation. In this paper, for a single wall made of two coupled panels, an equivalent frame model for the corresponding analysis is proposed, based on both a simplified and more detailed procedure. The equivalent frame for a single wall consists of a beam cantilever element, with a specific flexural and shear stiffness, that takes into account the influence of the mechanical connections by means of a rotational elastic spring placed at the base of the frame. The proposed simplified method, according to the hypotheses commonly adopted in literature, assumes that the panels show infinite compression stiffness at the base-section, but in addition takes into account the reduction of stiffness due to the coupling behaviour. Conversely, the detailed method considers also the effect of the compression deformability at the base of the panels. The analytical results of the equivalent frame, compared with the ones given by a FEM model based on shell elements, show good agreement.
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11 records – page 1 of 2.