Skip header and navigation

5 records – page 1 of 1.

Advanced Modelling of Cross Laminated Timber (CLT) Panels in Bending

https://research.thinkwood.com/en/permalink/catalogue1796
Year of Publication
2015
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Franzoni, Lorenzo
Lebée, Arthur
Lyon, Florent
Forêt, Gilles
Publisher
HAL archives-ouvertes.fr
Year of Publication
2015
Format
Presentation
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Mechanical Properties
Keywords
Bending
Model
Panels
Shear
Stiffness
Failure Behavior
Shear Force
Reference Test
Conference
Euromech Colloquim 556 Theoretical Numerical and Experimental Analyses of Wood Mechanics
Research Status
Complete
Notes
May 2015, Dresde, Germany
Summary
Cross Laminated Timber (CLT) panels are more and more common in timber construction. When submitted to out-of-plane loads, they can be considered as multi-layer plates with anisotropic behaviour. Their main structural issue is the low transverse shear strength of cross layers which leads to rolling shear failure. In addition the fabrication process can include or not lateral boards’ gluing. The resulting discontinuities can be considered as weakly heterogeneous and influence the mechanical response. Moreover the timber construction market requires new technical solutions for CLT, like periodic voids within the panel. This solution leads to lighter and more thermally efficient floors. However, the spaced voids between boards increase the heterogeneity of the panel and therefore the complexity of stresses’ distribution.
Online Access
Free
Resource Link
Less detail

Basis of Design Principles for Timber Structures

https://research.thinkwood.com/en/permalink/catalogue1939
Year of Publication
2018
Topic
Serviceability
Design and Systems
Material
CLT (Cross-Laminated Timber)
Author
Abeysekera, Ishan
Baravalle, Michele
Brandner, Reinhard
Colling, François
Fink, Gerhard
Hamm, Patricia
Hochreiner, Georg
Honfi, Dániel
Ilharco, Tiago
Jockwer, Robert
Kleinhenz, Miriam
Kohler, Jochen
Lawrence, Andrew
Marcroft, Julian
Mikoschek, Michael
Toratti, Tomi
Editor
Fink, Gerhard
Honfi, Dániel
Kohler, Jochen
Dietsch, Philipp
Publisher
COST (European Cooperation in Science and Technology)
Year of Publication
2018
Format
Book/Guide
Material
CLT (Cross-Laminated Timber)
Topic
Serviceability
Design and Systems
Keywords
Eurocode
Deflection
Vibrations
Serviceability Limit States
Eurocode 5
Dowel Type Fastener
Failure Behavior
Research Status
Complete
Summary
This report represents the results of the activities performed in working group 1, Basis of Design. The most important task of working group 1 was the defragmentation and harmonization of techniques and methods that are necessary to prove the reliable, safe and economic application of timber materials or products in the construction industry. This report is structured into five parts. At first general principles regarding the design formats are addressed (Part I). Afterwords timber specific aspects regarding code calibration (Part II) and serviceability (Part III) are summarized. In Part IV other demanding issues for the implementation into Eurocode 5 are addressed. Here also summaries of joint activities with other working groups on cross laminated timber and timber connections are presented. The report concludes with a guideline for data analysis (Part V).
Online Access
Free
Resource Link
Less detail

Behavior of Strengthened Timber Concrete Composite Under Axial Loads

https://research.thinkwood.com/en/permalink/catalogue2778
Year of Publication
2021
Topic
Mechanical Properties
Material
Timber-Concrete Composite
Author
El-Salakawy, Tarek
Gamal, Amr
Publisher
ScienceDirect
Year of Publication
2021
Format
Journal Article
Material
Timber-Concrete Composite
Topic
Mechanical Properties
Keywords
Axial Loading
Strengthening
Wire Mesh
Epoxy
Modulus of Elasticity
Failure Mode
Ductility
Post Failure Behavior
Research Status
Complete
Series
Case Studies in Construction Materials
Summary
The research study focuses on different strengthening techniques for timber concrete composites (TCC) using different types of wire and wire mesh integrated with a layer of epoxy on a timber core embedded in concrete using experimental and analytical procedure. The impact of TCC on axial compression performance, modulus of elasticity, failure mode and post failure behavior and ductility were compared to reference concrete specimens. Different types of wire and wire mesh used in strengthening of the timber core, timber core size and reinforcement in the concrete cylinder were all parameters considered in this study. Timing of application of the epoxy on the wire strengthened timber core was very important. For structural applications, where the weight reduction and ductility as well as post failure endurance are essential, the development of this composite is recommended. The ratio of the ductility index to the weight is discussed. The light weight of the timber composite, and the increased ductility were noted in this study. An equation to estimate the axial compression capacity of the strengthened timber concrete composite was developed in this study. This study will pave the way for further applications for timber concrete composite aiming at reducing dead weight of concrete and the reducing the amount of concrete and steel in construction.
Online Access
Free
Resource Link
Less detail

Structural Behaviour of Glued Laminated Timber Beams with Unreinforced and Reinforced Notches

https://research.thinkwood.com/en/permalink/catalogue311
Year of Publication
2014
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Jockwer, Robert
Organization
ETH Zurich
Year of Publication
2014
Format
Thesis
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Mechanical Properties
Keywords
Finite Element Model
Load Carrying Capacity
notch
Monte Carlo
Failure Behavior
Research Status
Complete
Summary
In this thesis the reliability of the design of unreinforced notched beams is evaluated and recommendations for the design of reinforced notched beams are given. The review of design approaches for reinforced notched beams shows, that so far the reinforcement is designed only with regard to the perpendicular to grain force acting in the notch corner. The evaluation of test results from literature shows that a stiff reinforcement has the best reinforcing effect but initial cracking cannot be prevented. The failure behaviour of the reinforced notch is studied in more detail by means of experiments and a FE model. Initial cracking of the reinforced notch comes along with crack opening, whereas ultimate failure with excessive crack growth is accompanied by shearing of the crack. An analytical model is presented for the description of the structural behaviour of reinforced notched beams. The parallel and perpendicular to the grain stiffness of the reinforcement is accounted for in the model. A high stiffness of the reinforcement parallel to the grain is required in order to reduce the mode 1 loading of the notch corner and to prevent initial cracking. The mode 2 loading of the crack increases with increasing crack length. In order to achieve higher load-carrying capacities for notched beams with longer cracks, reinforcement with high stiffness parallel to the grain is required. Recommendations are given for the required reinforcement of notched beams in order to restore the shear capacity of the reduced cross-section.
Online Access
Free
Resource Link
Less detail

Study on Seismic Performance of Building Structure with Cross Laminated Timber: Part 12: Objective and Loading Procedure and Accuracy of Static Loading Test

https://research.thinkwood.com/en/permalink/catalogue983
Year of Publication
2013
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Kaiko, Naoto
Hamamoto, Takashi
Gosei, Murakami
Yahaura, Sota
Miyake, Tatsuya
Goto, Hiroshi
Nakagawa, Takafumi
Yasumura, Motoi
Organization
Architectural Institute of Japan
Year of Publication
2013
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Keywords
Static Loading Test
Failure Behavior
Shear Force
Seismic Performance
Research Status
Complete
Summary
Cross-laminated timber (CLT) is a relatively new heavy timber construction material (also referred to as massive timber) that originated in central Europe and quickly spread to building applications around the world over the past two decades. Using dimension lumber (typically in the range of 1× or 2× sizes) glue laminated with each lamination layer oriented at 90° to the adjacent layer, CLT panels can be manufactured into virtually any size (with one dimension limited by the width of the press), precut and pregrooved into desirable shapes, and then shipped to the construction site for quick installation. Panelized CLT buildings are robust in resisting gravity load (compared to light-frame wood buildings) because CLT walls are effectively like solid wood pieces in load bearing. The design of CLT for gravity is relatively straightforward for residential and light commercial applications where there are plenty of wall lines in the floor plan. However, the behavior of panelized CLT systems under lateral load is not well understood especially when there is high seismic demand. Compared to light-frame wood shear walls, it is relatively difficult for panelized CLT shear walls to achieve similar levels of lateral deflection without paying special attention to design details, i.e., connections. A design lacking ductility or energy dissipating mechanism will result in high acceleration amplifications and excessive global overturning demands for multistory buildings, and even more so for tall wood buildings. Although a number of studies have been conducted on CLT shear walls and building assemblies since the 1990s, the wood design community’s understanding of the seismic behavior of panelized CLT systems is still in the learning phase, hence the impetus for this article and the tall CLT building workshop, which will be introduced herein. For example, there has been a recent trend in engineering to improve resiliency, which seeks to design a building system such that it can be restored to normal functionality sooner after an earthquake than previously possible, i.e., it is a resilient system. While various resilient lateral system concepts have been explored for concrete and steel construction, this concept has not yet been realized for multistory CLT systems. This forum article presents a review of past research developments on CLT as a lateral force-resisting system, the current trend toward design and construction of tall buildings with CLT worldwide, and attempts to summarize the societal needs and challenges in developing resilient CLT construction in regions of high seismicity in the United States.
Online Access
Free
Resource Link
Less detail