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212 records – page 1 of 22.

The strength of Glulam Beams with Holes - A Probabilistic Fracture Mechanics Method and Experimental Tests

https://research.thinkwood.com/en/permalink/catalogue2238
Year of Publication
2009
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams

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

Structural Performance of Box Based Cross Laminated Timber System Used in Floor Applications

https://research.thinkwood.com/en/permalink/catalogue1171
Year of Publication
2011
Topic
Mechanical Properties
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Chen, Yue
Organization
University of British Columbia
Year of Publication
2011
Country of Publication
Canada
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Mechanical Properties
Acoustics and Vibration
Keywords
Three Point Bending Test
Vertical Deflection
Bending Stiffness
Fundamental Frequency
Finite Element Analysis
Language
English
Research Status
Complete
Summary
The current outbreak of Mountain Pine Beetle (MPB) in the province of British Columbia (B.C.) is the most extensive disturbance event occurring in North American forests in recorded history. The concept of converting the beetle killed wood into engineered wood products by defect removal and reconstitution is employed to maximize value recovery from the material. Cross Laminated Timber (CLT), which is produced in modular form and can be utilized as part of a structural system for floor, wall or roof elements, is considered as an excellent application of the concept. CLT originates from Europe. Such products have been developed as a proprietary product by individual companies aimed at servicing specific markets. There is a need to investigate different ways of making CLT and to define its structural performance suitable for North America. The main focus of this study is to investigate the structural performance of box based CLT system used in floor applications. Comprehensive three dimensional finite element models, which can be used to analyze the mechanical and vibration behavior of the plate and box type structures, were developed. Four prototype box elements, each having five replicates, were designed and manufactured locally. Third point bending tests were conducted on the specimens in the Timber Engineering and Applied Mechanics (TEAM) Laboratory at the University of British Columbia. The numerical analysis agreed well with experimental data in terms of vertical deflection and bending stiffness. Vibration, which is critical to floor serviceability, was also studied. Three types of excitation were applied to measure the fundamental frequency of the twenty specimens. Finite element analysis provided good predictions of fundamental frequency values comparing to the experimental results. A local built demonstration building, L41home, was presented and analyzed as an example using the tools developed in this study for CLT applications. As a pioneer research of CLT materials in North America, this work has contributed to the understanding of the structural performance of floor systems using CLT panels for the commercial and residential applications.
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Cross Laminated Timber (CLT) Plane Structures Under Concentrated Loading from Point Supports - Shear Design including Reinforcements

https://research.thinkwood.com/en/permalink/catalogue1572
Year of Publication
2011
Topic
Design and Systems
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Mestek, Peter
Organization
Technical University of Munich
Year of Publication
2011
Country of Publication
Germany
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Topic
Design and Systems
Mechanical Properties
Keywords
Point-Supported
Concentrated Loads
Shear
Rolling Shear
Reinforcement
Screws
Biaxial
Language
German
Research Status
Complete
Summary
This thesis deals with the shear design of Cross Laminated Timber (CLT) elements stressed by concentrated loads which are locally reinforced by means of self-tapping screws with continuous threads. A simplified model is presented using an effective width for the calculation of the shear stresses in the vicinity of point supports or concentrated loads. Laboratory tests supply material-mechanical principles to determine the interaction of rolling shear stresses and compression perpendicular to the grain. In addition to experimental tests theoretical models are developed to examine the load bearing behaviour of CLT-elements reinforced by self-tapping screws. Preliminary tests with plate elements provide initial experience with these reinforcements under biaxial load transfer. Finally a design concept validated by means of the test results is proposed.
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Investigating the Performance of Wood Portal Frames as Alternative Bracing Systems in Light-Frame Wood Buildings

https://research.thinkwood.com/en/permalink/catalogue2240
Year of Publication
2012
Topic
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
LSL (Laminated Strand Lumber)
Application
Frames

Hygrothermal Properties of Cross Laminated Timber and Moisture Response of Wood at High Relative Humidity

https://research.thinkwood.com/en/permalink/catalogue12
Year of Publication
2012
Topic
Moisture
Material
CLT (Cross-Laminated Timber)

Air-Coupled Ultrasound Propagation and Novel Non-Destructive Bonding Quality Assessment of Timber Composites

https://research.thinkwood.com/en/permalink/catalogue13
Year of Publication
2012
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Martín, Sergio
Organization
ETH Zurich
Year of Publication
2012
Country of Publication
Switzerland
Format
Thesis
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Keywords
Adhesives
Bonding
Delamination
Failure
Non-Destructive Testing
Air-coupled Ultrasound (ACU)
Finite-Difference Time-Domain (FDTD) model
Language
English
Research Status
Complete
Summary
Glued laminated timber (glulam) is manufactured by gluing and stacking timber lamellas, which are sawn and finger-jointed parallel to the wood grain direction. This results in a sustainable and competitive construction material in terms of dimensional versatility and load-carrying capacity. With the proliferation of glued timber constructions, there is an increasing concern about safety problems related to adhesive bonding. Delaminations are caused by manufacturing errors and in service climate variations simultaneously combined with long-sustained loads (snow, wind and gravel filling on flat roofs). Several recent building collapses were related to bonding failure, which should be prevented in the future with a timely defect detection. As an outlook, the feasibility of air-coupled ultrasound tomography was demonstrated with numerical tests and preliminary experiments on glulam. The FDTD wave propagation model was excited by the difference of the time-reversed sound fields transmitted through a test and a reference (defect-free) glulam cross-section. Both datasets were obtained with the same SLT setup. Wave convergences then provided a map of bonding defects along the height and width of the inspected glulam cross-sections. Further research is envisaged in this direction
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Fire Resistance of Laminated Veneer Lumber (LVL) and Cross-Laminated Timber (XLAM) Elements

https://research.thinkwood.com/en/permalink/catalogue97
Year of Publication
2012
Topic
Fire
Material
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
Author
Menis, Agnese
Organization
University of Cagliari
Year of Publication
2012
Country of Publication
Italy
Format
Thesis
Material
CLT (Cross-Laminated Timber)
LVL (Laminated Veneer Lumber)
Topic
Fire
Keywords
Numerical models
Finite element (FE) model
Abaqus
Testing
Language
English
Research Status
Complete
Summary
This research investigates the fire behaviour of laminated veneer lumber elements and cross-laminated timber panels. The study focused on some research questions regarding the fire resistance of unprotected and protected timber structural elements, the possibility to predict accurately the fire behaviour of timber elements through numerical modelling, and the accuracy of analytical estimations of fire resistance using simplified design methods. Experimental tests of small and large specimens exposed to fire on one or more sides and subjected to different types and levels of load were performed. The results highlight the good performance of timber structural elements in fire conditions. The collected data were used to validate two- and three-dimensional models implemented in the general purpose finite element code Abaqus. Thermal and mechanical analyses were carried out to estimate the temperature distribution within unprotected and protected cross-sections of different sizes, the fire resistance and the displacement of timber elements loaded inplane and out-of-plane
Online Access
Free
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Damping in Timber Structures

https://research.thinkwood.com/en/permalink/catalogue106
Year of Publication
2012
Topic
Design and Systems
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Floors
Beams
Author
Labonnote, Nathalie
Organization
Norwegian University of Science and Technology
Year of Publication
2012
Country of Publication
Norway
Format
Thesis
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Floors
Beams
Topic
Design and Systems
Keywords
Damping
Model
Panels
Spruce
Testing
Vibrations
Language
English
Research Status
Complete
Summary
Key point to development of environmentally friendly timber structures, appropriate to urban ways of living, is the development of high-rise timber buildings. Comfort properties are nowadays one of the main limitations to tall timber buildings, and an enhanced knowledge on damping phenomena is therefore required, as well as improved prediction models for damping. The aim of this work has consequently been to estimate various damping quantities in timber structures. In particular, models have been derived for predicting material damping in timber members, beams or panels, or in more complex timber structures, such as floors. Material damping is defined as damping due to intrinsic material properties, and used to be referred to as internal friction. In addition, structural damping, defined as damping due to connections and friction in-between members, has been estimated for timber floors.
Online Access
Free
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Moisture Response of Wall Assemblies of Cross-Laminated Timber Construction in Cold Canadian Climates

https://research.thinkwood.com/en/permalink/catalogue143
Year of Publication
2012
Topic
Serviceability
Moisture
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Lepage, Robert
Organization
University of Waterloo
Year of Publication
2012
Country of Publication
Canada
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Serviceability
Moisture
Keywords
Canada
Climate
Decay
Durability
Hem-Fir
Hygrothermal
Mold
Relative Humidity
Rot
Simulation
SPF
Water Vapour Permeability
Language
English
Research Status
Complete
Summary
Wood is a highly versatile renewable material (with carbon sequestering properties), that is light in weight, has good strength properties in both tension and compression while providing good rigidity and toughness, and good insulating properties (relative to typical structural materials). Engineered wood products combine the benefits of wood with engineering knowledge to create optimized structural elements. Cross-laminated timber (CLT), as one such engineered wood product, is an emerging engineering material which provides great opportunities for the building industry. While building with wood has many benefits, there are also some concerns, particularly decay. Should wood be exposed to elevated amounts of moisture, rots and moulds may damage the product or even risk the health of the occupants. As CLT panels are a relatively new engineered wood product, the moisture characteristics have yet to be properly assessed.
Online Access
Free
Resource Link
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212 records – page 1 of 22.