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11 records – page 1 of 2.

Adhesive Bonding of Structural Hardwood Elements

https://research.thinkwood.com/en/permalink/catalogue75
Year of Publication
2015
Topic
Mechanical Properties
Serviceability
Moisture
Material
Glulam (Glue-Laminated Timber)
CLT (Cross-Laminated Timber)
Author
Hassani, Mohammad
Organization
ETH Zurich
Year of Publication
2015
Country of Publication
Switzerland
Format
Thesis
Material
Glulam (Glue-Laminated Timber)
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Serviceability
Moisture
Keywords
Abaqus
Adhesives
Beech
Bonding
Delamination
Finite Element Model
Fracture
Long-term
Model
Hardwood
Language
English
Research Status
Complete
Summary
The current research investigated the delamination process of adhesively bonded hardwood (European beech) elements subject to changing climatic conditions. For the study of the long-term fracture mechanical behavior of gluedlaminated components under varying moisture content, the role of moisture development, time- and moisture-dependent responses are absolutely crucial. For this purpose, a 3D orthotropic hygro-elastic, plastic, visco-elastic, mechano-sorptive wood constitutive model with moisture-dependent material constants was presented in this work. Such a comprehensive material model is capable to capture the true historydependent stress states and deformations which are essential to achieve reliable design of timber structures. Besides the solid wood substrates, the adhesive material also influences the interface performance considerably. Hence, to gain further insight into the stresses and deformations generated in the bond-line, a general hygro-elastic, plastic, visco-elastic creep material model for adhesive was introduced as well. The associated numerical algorithms developed on the basis of additive decomposition of the total strain were formulated and implemented within the Abaqus Finite Element (FE) package. Functionality and performance of the proposed approach were evaluated by performing multiple verification simulations of wood components, under different combinations of mechanical loading and moisture variation. Moreover, the generality and efficiency of the presented approach was further demonstrated by conducting an application example of a hybrid wood element.
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Dynamic Effects in Reinforced Timber Beams at Time of Timber Fracture

https://research.thinkwood.com/en/permalink/catalogue2303
Year of Publication
2015
Topic
Design and Systems
Application
Beams

Evaluate Bearing Stress of Glulam Using Digital Image Correlation

https://research.thinkwood.com/en/permalink/catalogue687
Year of Publication
2014
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Jeong, Gi-Young
Park, Moon-Jae
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Digital Image Correlation
Drift Pins
Bearing Stress
Strain Distribution
Fracture Behaviour
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
The goal of this study is to evaluate the effect of different sizes of drift pins (12mm, 16mm, 20mm, 30mm) and six orientations of glulam associated with pin positions (RL, TL, LR, TR, LT, RT) on bearing stress and strain distributions of glulam using digital image correlation (DIC). Different bearing stresses, strain distributions, and fracture behaviours associated with the orientation of the glulam and pin sizes were observed. As the diameter of drift pins increased, the bearing strength increased regardless of the orientation. However, the trends of failure behaviours did not change by the pin size.
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Flexural Performance of Novel Nail-Cross-Laminated Timber Composite Panels

https://research.thinkwood.com/en/permalink/catalogue2649
Year of Publication
2020
Topic
Mechanical Properties
Design and Systems
Material
CLT (Cross-Laminated Timber)
Author
Zhang, Yannian
Nehdi, Moncef
Gao, Xiaohan
Zhang, Lei
Publisher
MDPI
Year of Publication
2020
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Design and Systems
Keywords
Panels
Flexural Performance
Nails
Bending
Model
Prediction
Fracture
Language
English
Research Status
Complete
Series
Applied Sciences
Summary
Cross-laminated timber (CLT) is an innovative wood panel composite that has been attracting growing interest worldwide. Apart from its economic benefits, CLT takes full advantage of both the tensile strength parallel to the wood grain and its compressive strength perpendicular to the grain, which enhances the load bearing capacity of the composite. However, traditional CLT panels are made with glue, which can expire and lose effectiveness over time, compromising the CLT panel mechanical strength. To mitigate such shortcomings of conventional CLT panels, we pioneer herein nail-cross-laminated timber (NCLT) panels with more reliable connection system. This study investigates the flexural performance of NCLT panels made with different types of nails and explores the effects of key design parameters including the nail incidence angle, nail type, total number of nails, and number of layers. Results show that NCLT panels have better flexural performance than traditional CLT panels. The failure mode of NCLT panels depends on the nail angle, nail type, and quantity of nails. A modified formula for predicting the flexural bearing capacity of NCLT panels was proposed and proven accurate. The findings could blaze the trail for potential applications of NCLT panels as a sustainable and resilient construction composite for lightweight structures.
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Matching Tests of Brittle Failure of Bottom Rail Versus Tensile Strength Perpendicular to the Grain and Fracture Energy in RT and TR Plane

https://research.thinkwood.com/en/permalink/catalogue380
Year of Publication
2014
Topic
Mechanical Properties
Material
Solid-sawn Heavy Timber
Application
Shear Walls
Author
Caprolu, Giuseppe
Organization
Luleå University of Technology
Year of Publication
2014
Country of Publication
Sweden
Format
Report
Material
Solid-sawn Heavy Timber
Application
Shear Walls
Topic
Mechanical Properties
Keywords
Tensile Strength
Fracture Energy
Language
English
Research Status
Complete
Summary
A research study on a new plastic design method for timber frame shear walls partially anchored is under development in Sweden [1]. In this research an important focus has been put on the problem of the possible splitting of the bottom rail. In partially anchored timber frame shear walls there are not hold downs taking the vertical loads so the corresponding forces can be replaced by vertical loads from upper storeys, the roof or connection between shear wall and transversal wall. In this case the bottom row of rail transmits the vertical forces in the sheathing to the bottom rail (instead of the vertical stud) where the anchor bolts will further transmit the forces into the foundation. The bottom rail is then subjected to tensile load perpendicular to the grain, which can be often causes a splitting failure The aim of this report is to present the results of three experimental studies: tensile strength perpendicular to the grain in radial and tangential direction, fracture energy with TR and RT orientations and bottom rail. The experimental programs have been conducted at two different periods and places: bottom rail tests at Umeå University in October 2012 and tensile strength perpendicular to grain and fracture energy at SP in Stockholm in June 2013.
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Mechanical Performance of Glue Joints in Structural Hardwood Elements

https://research.thinkwood.com/en/permalink/catalogue1517
Year of Publication
2016
Topic
Mechanical Properties
Connections
Material
Glulam (Glue-Laminated Timber)
Author
Niemz, Peter
Ammann, Samuel
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Connections
Keywords
Beech
Joints
Crack Propagation
PRF
Delamination Test
Shear Strength
Fracture Energy
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 526-533
Summary
Mechanical Performance of Glue Joints in Structural Hardwood Elements as those for solid beech wood, wherein also the crack propagation takes place. It can be concluded that such joints have the necessary strength to be used in timber constructions. Joints of phenol resorcinol formaldehyde (PRF) showed constantly good results, the determined characteristics generally lay in the same range as for beech wood.
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Predicting Failure of Notched Cross-Laminated Timber Plates Including the Effect of Environmental Stresses

https://research.thinkwood.com/en/permalink/catalogue2354
Year of Publication
2020
Topic
Mechanical Properties
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Nairn, John
Year of Publication
2020
Country of Publication
United States
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Mechanical Properties
Design and Systems
Keywords
Delamination
Fracture Mechanisms
Residual Stresses
Language
English
Research Status
Complete
Series
Wood Material Science & Engineering
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Free
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Study on Seismic Performance of Building Construction with Cross Laminated Timber: Part 14: Deformation of Joints and Fracture Behavior on Three Story Full-Scale Static Load Test

https://research.thinkwood.com/en/permalink/catalogue981
Year of Publication
2013
Topic
Seismic
Connections
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Nasu, Hideyuki
Yahaura, Sota
Gosei, Murakami
Goto, Hiroshi
Hamamoto, Takashi
Miyake, Tatsuya
Yasumura, Motoi
Organization
Architectural Institute of Japan
Year of Publication
2013
Country of Publication
Japan
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Connections
Keywords
Static Load Tests
Mid-Rise
Fracture Behavior
Full Scale
Seismic Performance
Language
Japanese
Research Status
Complete
Summary
This paper gives a bibliographical review of the finite element methods (FEMs) applied in the analysis of wood. The added bibliography at the end of this article contains 300 references to papers and conference proceedings on the subject that were published between 1995 and 2004. The following topics are included: Wood as a construction material—material and mechanical properties; wood joining and fastening; fracture mechanics problems; drying process, thermal properties; other topics. Wood products and structures—lumber; glulam, panels, wood composites; trusses and frames; floors, roofs; bridges; other products/structures.
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Study on Shear Performance of CLT Joints Using Long Vise Part 1 Summary of Experiments and Test Pieces

https://research.thinkwood.com/en/permalink/catalogue1009
Year of Publication
2014
Topic
Connections
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Author
Nasu, Hideyuki
Township, Onishi
Karibe, Yuki
Organization
Architectural Institute of Japan
Year of Publication
2014
Country of Publication
Japan
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Topic
Connections
Keywords
Floor-Wall Connection
Mid-Rise
Shear Test
Fracture Behavior
Long Vise
Joints
Language
Japanese
Research Status
Complete
Summary
Innovative steel - Cross Laminated Timber (CLT) connections are key elements in developing hybrid steeltimber composite floors with desirable strength and serviceability performance. The performance of floors mainly relies on the load-slip behavior of connections for composite action. The long-term behavior of timber is mainly affected by elastic and mechano-sorptive creep, resulting in a different total slip than the initially observed one. In this study, the long-term load-slip behavior of two different types of connections with pre-tensioned high-strength bolts and dog screws are experimentally assessed at two different stress levels. Furthermore, the effect of grain orientation on the results is studied by considering specimens with parallel and perpendicular grain orientations under sustained loads. Load-slip curves show a stable performance of a composite action over time. Furthermore, an analytical model is fitted to the loadslip vs time data which can be used to predict long-term behavior of floors in future.
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Study on Shear Performance of CLT Joints Using Long Vise Part 2 Result of Experiments, Consideration and Conclusion

https://research.thinkwood.com/en/permalink/catalogue1008
Year of Publication
2014
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Author
Township, Onishi
Nasu, Hideyuki
Karibe, Yuki
Organization
Architectural Institute of Japan
Year of Publication
2014
Country of Publication
Japan
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Topic
Connections
Mechanical Properties
Keywords
Floor-Wall Connection
Joints
Mid-Rise
Shear Test
Fracture Behavior
Long Vise
Language
Japanese
Research Status
Complete
Summary
Innovative steel - Cross Laminated Timber (CLT) connections are key elements in developing hybrid steeltimber composite floors with desirable strength and serviceability performance. The performance of floors mainly relies on the load-slip behavior of connections for composite action. The long-term behavior of timber is mainly affected by elastic and mechano-sorptive creep, resulting in a different total slip than the initially observed one. In this study, the long-term load-slip behavior of two different types of connections with pre-tensioned high-strength bolts and dog screws are experimentally assessed at two different stress levels. Furthermore, the effect of grain orientation on the results is studied by considering specimens with parallel and perpendicular grain orientations under sustained loads. Load-slip curves show a stable performance of a composite action over time. Furthermore, an analytical model is fitted to the loadslip vs time data which can be used to predict long-term behavior of floors in future.
Online Access
Free
Resource Link
Less detail

11 records – page 1 of 2.