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10 records – page 1 of 1.

Developing a Large Span Timber-based Composite Floor System for Highrise Office Buildings Phase I

https://research.thinkwood.com/en/permalink/catalogue2803
Year of Publication
2021
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
LSL (Laminated Strand Lumber)
Glulam (Glue-Laminated Timber)
Application
Floors
Author
Zhang, Chao
Lee, George
Lam, Frank
Organization
University of British Columbia
Year of Publication
2021
Country of Publication
Canada
Format
Report
Material
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
LSL (Laminated Strand Lumber)
Glulam (Glue-Laminated Timber)
Application
Floors
Topic
Design and Systems
Keywords
Box Girder
Timber Composite Floor
Span
High-Rise
Tall Wood Buildings
Stiffness
Composite Action
Language
English
Research Status
Complete
Summary
This project proposes a timber-based composite floor that can span 12 m and be used in the construction of 40+ story office buildings. This floor system integrates timber panels and timber beams to form a continuous box girder structure. The timber panels function as the flanges and the timber beams as the web. The beams are spaced and connected to the flange panels so that sufficient bending stiffness of a 12 m span can be achieved via the development of composite action. The current phase of this project studied the performance of the connections between timber elements in the proposed composite member. Six types of connections using different flange material and connection techniques were tested: Cross Laminated Timber (CLT), Laminated Strand Lumber (LSL), Laminated Veneer Lumber (LVL), and Post Laminated Veneer Lumber (PLVL). Glulam was used as the web. The majority of the connections used self-tapping wood screws except one had notches. The load-carrying capacity, stiffness, and ductility of the connections were measured. The stiffness of CLT, LSL, and PLVL connections was in the same range, 19-20 kN/mm per screw. Amongst the three, LSL had the highest peak load and PLVL had the highest proportional limit. The stiffness of the two LVL screw connections was around 13 kN/mm. The notched LVL connection had significantly higher stiffness than the rest, and its peak load was in the same range as LSL, but the failure was brittle. LVL was used to manufacture the full scale timber composite floor element. With a spacing of 400 mm, the overall stiffness reached 33689 N
mm2×109, which was 2.5 times the combined stiffness of two Glulam beams. The predicted overall stiffness based on Gamma method was within 5% of the tested value, and the estimated degree of composite action was 68%. From both the test results and analytical modeling, the number of screws may be further reduced to 50% or less of the current amount, while maintaining a high level of stiffness. Future work includes testing the composite floor under different screw spacings, investigating the effect of concrete topping, and the connections between floor members and other structural elements.
Online Access
Free
Resource Link
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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.
Online Access
Free
Resource Link
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The Fire Performance of Timber Floors in Multi-Storey Buildings

https://research.thinkwood.com/en/permalink/catalogue234
Year of Publication
2013
Topic
Fire
Design and Systems
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Author
O'Neill, James
Organization
University of Canterbury
Year of Publication
2013
Country of Publication
New Zealand
Format
Thesis
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Topic
Fire
Design and Systems
Keywords
Abaqus
Finite Element Model
Full Scale
Furnace Tests
Charring Rate
Dead Load
Live Load
Zero-Strength Layer
Language
English
Research Status
Complete
Summary
This research investigated the fire performance of unprotected timber floors, focussing on composite joist floors, composite box floors and timber-concrete composite floors. The study of these floors was conducted using the finite element software ABAQUS using a thermo-stress analysis in three dimensions, and with experimental fire tests of floor assemblies. The major goal of this research was to develop a simplified design approach for timber floors, validated against the numerical and experimental work. Four furnace tests were conducted on unprotected timber floor systems in the full-scale furnace at the BRANZ facilities in New Zealand. A sequentially coupled thermal-stress analysis was conducted to determine the effects of a fire on floor assemblies under load. The thermal modelling predicted the charring damage of the floors tested in the experiments to within a few millimetres of precision, and the simplified assumptions made in relation to fire inputs, boundary conditions, mesh refinement and effective material parameters were accurate to the desired level of precision. A sensitivity study was conducted comparing different mesh sizes, time step sizes, material model approaches and software suites to determine any shortfalls which may be encountered in the analysis. It was found that a material model adopting a latent heat approach was the most adequate for modelling timber in fires using these effective values, and mesh sizes of up to 6 mm produced relatively precise results. The structural modelling predicted the displacement response and failure times of the floors to within 20% of the experimental data, and the simplified assumptions made in relation to fire inputs, boundary conditions, mesh refinement and effective material properties were once again accurate to the desired level of precision. A modification to the reduction in tension strength at elevated temperatures was proposed to better predict the observed behaviour. A sensitivity study concluded that the material model definition plays a vital role in the output of the modelling. Non-standard fire exposures were also modelled for completeness. A simplified design method to estimate the fire resistance of unprotected floor assemblies was also developed. The method uses a bi-linear charring rate the assumption of a zero strength layer in the timber. The method was compared to the experimental data from this research and others around the world. The results were also compared to other charring rate methodologies from around the world.
Online Access
Free
Resource Link
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Displacement-Based Seismic Design of Timber Structures

https://research.thinkwood.com/en/permalink/catalogue1891
Year of Publication
2011
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
Other Materials
Application
Wood Building Systems
Walls
Floors
Beams
Columns
Frames

A Theoretical Approach Towards Ressource Efficiency in Multi-Story Timber Buildings Through BIM and Lean

https://research.thinkwood.com/en/permalink/catalogue1910
Year of Publication
2018
Topic
Design and Systems
Cost
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Light Frame (Lumber+Panels)
Application
Wood Building Systems
Walls
Columns

Advanced Wood-Based Solutions for Mid-Rise and High-Rise Construction: Structural Performance of Post-Tensioned CLT Shear Walls with Energy Dissipators

https://research.thinkwood.com/en/permalink/catalogue1472
Year of Publication
2018
Topic
Design and Systems
Mechanical Properties
Seismic
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
LSL (Laminated Strand Lumber)
Application
Shear Walls
Author
Chen, Zhiyong
Popovski, Marjan
Symons, Paul
Organization
FPInnovations
Year of Publication
2018
Country of Publication
Canada
Format
Report
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
LSL (Laminated Strand Lumber)
Application
Shear Walls
Topic
Design and Systems
Mechanical Properties
Seismic
Keywords
Compression Tests
Compression Strength
Energy Dissipation
Post-Tensioned
Pres-Lam
Monotonic Loading
Reverse Cyclic Loading
Language
English
Research Status
Complete
Summary
The latest developments in seismic design philosophy have been geared towards developing of so called "resilient" or "low damage" innovative structural systems that can reduce damage to the structure while offering the same or higher levels of safety to occupants. One such innovative structural system is the Pres-Lam system that is a wood-hybrid system that utilizes post-tensioned (PT) mass timber components in both rigid-frame and wall-based buildings along with various types of energy disspators. To help implement the Pres-Lam system in Canada and the US, information about the system performance made with North American engineered wood products is needed. That information can later be used to develop design guidelines for the designers for wider acceptance of the system by the design community.Several components influence the performance of the Pres-Lam systems: the load-deformation properties of the engineered wood products under compression, load-deformation and energy dissipation properties of the dissipators used, placement of the dissipators in the system, and the level of post-tensioning force. The influence of all these components on the performance of Pres-Lam wall systems under gravity and lateral loads was investigated in this research project. The research project consisted of two main parts: material tests and system tests.
Online Access
Free
Resource Link
Less detail

Advancement of Timber Panels as Structural Elements in Composite Floor Systems of Timber-Steel Hybrid Structures

https://research.thinkwood.com/en/permalink/catalogue2785
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
Application
Floors
Hybrid Building Systems
Organization
Auburn University
Country of Publication
United States
Material
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
Application
Floors
Hybrid Building Systems
Topic
Design and Systems
Keywords
Timber-Steel Hybrid
Research Status
In Progress
Summary
Auburn University’s (AU) School of Forestry and Wildlife Sciences (SFWS) in Alabama actively works to increase awareness of the benefits of CLT along with hybrid systems for more widespread adoption in multiple building segments. AU’s two-year project proposal outlines a plan that will establish a preliminary design for the usage of a timber-steel composite system, utilizing CLT or laminated veneer lumber (LVL), as an option that will replace reinforced concrete slabs to improve the structural performance for buildings six stories or more.
Less detail

Feasibility Study of Mass-Timber Cores for the UBC Tall Wood Building

https://research.thinkwood.com/en/permalink/catalogue1895
Year of Publication
2018
Topic
Design and Systems
Environmental Impact
Seismic
Wind
Material
LVL (Laminated Veneer Lumber)
Application
Shafts and Chases

Advanced Wood-Based Solutions for Mid-Rise and High-Rise Construction: Modelling of Timber Connections Under Force and Fire

https://research.thinkwood.com/en/permalink/catalogue1473
Year of Publication
2018
Topic
Connections
Fire
Seismic
Design and Systems
Material
LVL (Laminated Veneer Lumber)
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Chen, Zhiyong
Ni, Chun
Dagenais, Christian
Organization
FPInnovations
Year of Publication
2018
Country of Publication
Canada
Format
Report
Material
LVL (Laminated Veneer Lumber)
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Connections
Fire
Seismic
Design and Systems
Keywords
Finite Element Model
Bolted Connection
Load-Displacement Curves
Language
English
Research Status
Complete
Summary
FPInnovations carried out a survey with consultants and researchers on the use of analytical models and software packages related to the analysis and design of mass timber buildings. The responses confirmed that a lack of suitable models and related information for material properties of timber connections was creating an impediment to the design and construction of this type of buildings. Furthermore, there is currently a lack of computer models and expertise for carrying out performance-based design for wood buildings, in particular seismic and/or fire performance design. In this study, a sophisticated constitutive model for wood-based composite material under stress and temperature was developed. This constitutive model was programmed into a user-subroutine which can be added to most general-purpose finite element software. The developed model was validated with test results of a laminated veneer lumber (LVL) beam and glulam bolted connection under force and/or fire.
Online Access
Free
Resource Link
Less detail

A 'Hybrid' Multi-Storey Building - Meeting Design Criteria in a Cost-Effective Way

https://research.thinkwood.com/en/permalink/catalogue1845
Year of Publication
2018
Topic
Design and Systems
Material
LVL (Laminated Veneer Lumber)
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Steel-Timber Composite
Timber-Concrete Composite
Other Materials
Application
Walls
Floors
Frames

10 records – page 1 of 1.