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67 records – page 1 of 7.

Analytical Model to Evaluate the Equivalent Viscous Damping of Timber Structures with Dowel-Type Fastener Connections

https://research.thinkwood.com/en/permalink/catalogue1893
Year of Publication
2012
Topic
Connections
Application
Frames
Author
Loss, Cristiano
Piazza, Maurizio
Zonta, Daniele
Year of Publication
2012
Format
Conference Paper
Application
Frames
Topic
Connections
Keywords
Equivalent Viscous Damping
Moment Resisting Joints
Dowel-Type Connections
Non-linear Dynamic Analysis
Metal Fasteners
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
July 16-19, 2012, Auckland, New Zealand
Summary
The Equivalent Viscous Damping (EVD) parameter is used to simplify the dynamic problem, passing from a non-linear solution of the system to a simple linear-elastic one. In the case of Direct Displacement-Based seismic Design (DDBD) methods, the EVD value allows direct design of structures, without an iterative computational process. This paper proposes a rational analytical formula to evaluate the EVD value of timber structures with dowel-type metal fastener connections. The EVD model is developed at the ultimate limit state, as a solution of the equilibrium problem related to an inelastic configuration. For a specific joint configuration, the EVD predicted via an analytical model was compared to experimental results. The proposed EVD model was validated using non-linear dynamic analysis on a portal frame, built with dowel-type fasteners arranged in two concentric crowns.
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An integrated design tool for timber plate structures to generate joints geometry, fabrication toolpath, and robot trajectories

https://research.thinkwood.com/en/permalink/catalogue2959
Year of Publication
2021
Topic
Connections
Application
Wood Building Systems
Author
Rogeau, Nicolas
Latteur, Pierre
Weinand, Yves
Organization
École Polytechnique Fédérale de Lausanne
Swiss Federal Institute of Technology in Zurich
Louvain School of Engineering
Publisher
Elsevier
Year of Publication
2021
Format
Journal Article
Application
Wood Building Systems
Topic
Connections
Keywords
Integrated Design
Timber Plate Structures
Wood Joints
Digital Fabrication
CNC Machining
Robotic Assembly
Robotic Arm
Modular Assembly
Assembly Sequence
Insertion Vector
Research Status
Complete
Series
Automation in Construction
Summary
This paper presents an integrated design tool for structures composed of engineered timber panels that are connected by traditional wood joints. Recent advances in computational architecture have permitted to automate the fabrication and assembly of such structures using Computer Numerical Control (CNC) machines and industrial robotic arms. While several large-scale demonstrators have been realized, most developed algorithms are closed-source or project-oriented. The lack of a general framework makes it difficult for architects, engineers and designers to effectively manipulate this innovative construction system. Therefore, this research aims at developing a holistic design tool targeting a wide range of architectural applications. Main achievements include: (1) a new data structure to deal with modular assemblies, (2) an analytical parametrization of the geometry of five timber joints, (3) a method to generate CNC toolpath while integrating fabrication constraints, and (4) a method to automatically compute robot trajectories for a given stack of timber plates.
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Assessing the Fire Integrity Performance of Cross-Laminated Timber Floor Panel-To-Panel Joints

https://research.thinkwood.com/en/permalink/catalogue185
Year of Publication
2016
Topic
Connections
Fire
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Dagenais, Christian
Organization
Carleton University
Year of Publication
2016
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Connections
Fire
Keywords
Finite Element Model
Thickness
Codes
Panel-to-Panel
Joints
Canada
US
Fire Resistance
Research Status
Complete
Summary
During the past few years, a relatively new technology has emerged in North America and changed the way professionals design and build wood structures: Cross-laminated Timber (CLT). CLT panels are manufactured in width ranging from 600 mm to 3 m. As such, fastening them together along their major strength axis is required in order to form a singular structural assembly resisting to in-plane and out-of-plane loading. Typical panel-to-panel joint details of CLT assemblies may consist of internal spline(s), single or double surface splines or half-lapped joints. These tightly fitted joint profiles should provide sufficient fire-resistance, but have yet to be properly evaluated for fire-resistance in CLT assemblies. The experimental portion of the study consisted at conducting ten (10) intermediate-scale fire-resistance tests of CLT floor assemblies with four (4) types of panel-to-panel joints and three (3) CLT thicknesses. The data generated from the intermediate-scale fire tests were used to validate a finite element heat transfer model, a coupled thermal-structural model and a simplified design model. The latter is an easy-to-use design procedure for evaluating the fire integrity resistance of the four commonly-used CLT floor assemblies and could potentially be implemented into building codes and design standards. Based on the test data and models developed in this study, joint coefficient values were derived for the four (4) types of CLT panel-to-panel joint details. Joint coefficients are required when assessing the fire integrity of joints using simple design models, such as the one presented herein and inspired from Eurocode 5: Part 1-2. The contribution of this study is to increase the knowledge of CLT exposed to fire and to facilitate its use in Canada and US by complementing current fire-resistance design methodologies of CLT assemblies, namely with respect to the fire integrity criterion. Being used as floor and wall assemblies, designers should be capable to accurately verify both the load-bearing and separating functions of CLT assemblies in accordance with fire-related provisions of the building codes, which are now feasible based on the findings of this study.
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Bond Behavior Between Softwood Glulam and Epoxy Bonded-In Threaded Steel Rod

https://research.thinkwood.com/en/permalink/catalogue450
Year of Publication
2015
Topic
Design and Systems
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Ling, Zhibin
Liu, Weiqing
Lam, Frank
Yang, Huifeng
Lu, Weidong
Publisher
American Society of Civil Engineers
Year of Publication
2015
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Design and Systems
Mechanical Properties
Keywords
Bonding Behavior
Failure Modes
Joints
Load Capacity
Softwood
Threaded Steel Rod
Pull-Pull
Research Status
Complete
Series
Journal of Materials in Civil Engineering
Summary
This study aims to develop an improved understanding of the interfacial bond behavior of softwood glulam joints with bonded-in threaded steel rod. A total of 39 glulam joints with bonded-in single-threaded steel rods were tested to failure in the pull-pull configuration. The test results were presented in term of failure modes, load-relative movement response, pullout strength, and the corresponding slip. The distributions of bonded-in rod axial strain, interfacial bond stress, and relative movement were also analyzed to evaluate the local bond stress– relative movement response in the bond line. The results confirmed that the bond-relative movement response is dependent on the locations along the anchorage length, and the bond-relative movement responses located near both the loaded end and the anchorage end were observed to be stiffer than those at other locations. Finally, the predictions for the load capacity of the glulam joints with bonded-in threaded steel rod were carried out based on several existing empirical formulas.
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Buildings Made of Dowel-Laminated Timber: Joint and Shear Wall Properties

https://research.thinkwood.com/en/permalink/catalogue1718
Year of Publication
2016
Topic
Mechanical Properties
Seismic
Connections
Material
DLT (Dowel Laminated Timber)
Application
Shear Walls
Author
Sandhaas, Carmen
Year of Publication
2016
Format
Conference Paper
Material
DLT (Dowel Laminated Timber)
Application
Shear Walls
Topic
Mechanical Properties
Seismic
Connections
Keywords
Joints
Load Carrying Capacity
Cyclic Tests
Energy Dissipation
Behaviour Factors
Numerical Models
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4589-4596
Summary
Dowel-laminated timber (DLT) elements consist of lamellae arranged side-by-side that are connected with beech dowels. Due to the glue-free DLT element layup, joints and shear walls potentially suffer from considerable reduction of stiffness and load carrying capacity as metal fasteners inserted perpendicular to the element plane may be placed in gaps between the single lamellae. Tests on typical joints showed that, depending on the fastener diameter, the remaining load carrying capacity of joints in DLT in comparison to joints in solid wood may be only 25%. Tests on DLT shear walls with different sheeting proved that the use of DLT structures as shear walls is only possible if at least one-sided sheeting is used. Cyclic tests on DLT shear walls demonstrated that the DLT construction typology has energy dissipation properties similar to traditional timber frame construction. Analogously, preliminary behaviour factors for DLT buildings evaluated with numerical models were also similar to those for timber frame buildings.
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Compression Perpendicular to Grain Behavior for the Design of a Prefabricated CLT Facade Horizontal Joint

https://research.thinkwood.com/en/permalink/catalogue1540
Year of Publication
2016
Topic
Connections
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Hybrid Building Systems
Author
Gasparri, Eugenia
Lam, Frank
Liu, Yingyang
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Hybrid Building Systems
Topic
Connections
Design and Systems
Keywords
Envelope
Joints
Self-Tapping Screws
Finite Element Analysis
Prefabricated
Vertical Loads
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 1088-1098
Summary
The present work aims to define horizontal joint dimension tolerances for newly proposed prefabricated façade systems for applications in tall cross laminated timber (CLT) buildings based on the compression perpendicular to grain characteristics of the component. This requires a thorough understanding of structural settlement under vertical loads which can vary at each floor height. An experimental program has been carried out with reference to the case of a platform frame building construction, where major perpendicular to grain compression of the floor can occur under high loads. Five-layer CLT specimens have been tested under compression via the application of a line load with steel plate as well as actual CLT wall specimens. Strengthening contribution using full threaded self-tapping wood screws has also been investigated. Results of deformation characteristics have been validated through a non-linear finite element analysis and further elaborated in order to outline implications in the design of a prefabricated façade.
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Contact Joints in Engineered Wood Products

https://research.thinkwood.com/en/permalink/catalogue1558
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Schmidt, Tobias
Blaß, Hans Joachim
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Contact Joints
Joints
Stiffness
Load Carrying Capacity
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 1321-1328
Summary
Cross laminated timber (CLT) members are especially suited for in-plane loads due to their high shear strength and stiffness. However, available connection techniques show limited load-carrying capacities and stiffness values in comparison to the shear capacity of CLT. To use the potential of CLT under in-plane loading, new connection techniques, so called contact joints, with increased stiffness and load-carrying capacities were developed. 10 different types of these contact joints, varying geometry and connector material, were studied. The developed contact joints can substitute traditional connection techniques.
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Cyclic Load Behaviour of Beam-to-Column Glulam Joints Combining Glued-in Rods with Steel Brackets

https://research.thinkwood.com/en/permalink/catalogue2028
Year of Publication
2018
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Ling, Zhibin
Liu, Weiqing
Yang, Huifeng
Xiang, Zhe
Year of Publication
2018
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Beam-to-Column
Joints
Glued-In Rods
Steel Brackets
Cyclic Loading
Monotonic Loading
Failure Modes
Stiffness
Ductility
Energy Dissipation
Hysteresis Loop
Douglas-Fir
Conference
World Conference on Timber Engineering
Research Status
Complete
Summary
This paper presents an experimental campaign conducted on the beam-to-column glulam joints combing glued-in rods and steel brackets (BCGS glulam joints) aiming to investigate the mechanical behaviour of these glulam joints under low cyclic loading. Three types of steel brackets were designed for connecting the beam and column combing with glued-in rods and to work as energy dissipaters. In each group of specimens (except for group MJ4), two specimens were tested under monotonic loading and the others were subjected to low cyclic loading. The test results were summarized comprehensively in terms of failure modes, joint stiffness, hysteresis loops, ductility and energy dissipation ability. Generally, the difference of load capacity between BCGS glulam joints and the beam-to-column glulam joints only with glued-in rods (BCG glulam joints) was not significant. The joint stiffness of BCG glulam joints was higher than that of the BCGS glulam joints, while the stiffness degradation of the later is slower than the former. The hysteresis loops of the BCGS glulam joints exhibited less pinching effect obviously compared with the BCG glulam joints, which indicated that the energy dissipation ability of the glulam joints with glued-in rods could be improved significantly by using the steel brackets as energy dissipaters. Moreover, it should be noted that the hysteresis loops of groups CJ1 showed slipping effect obviously during testing. This might due to the insufficient shear resistance of these two groups, so that further investigations on BCG glulam joints with shear-resisting components are urgently needed.
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Development of a Spring Model for the Structural Analysis of a Double-Layered Timber Plate Structure with Through-Tenon Joints

https://research.thinkwood.com/en/permalink/catalogue2034
Year of Publication
2018
Topic
Design and Systems
Mechanical Properties
Connections
Material
LVL (Laminated Veneer Lumber)
Author
Chi Nguyen, Anh
Weinand, Yves
Year of Publication
2018
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Topic
Design and Systems
Mechanical Properties
Connections
Keywords
Beech
Joints
Finite Element Model
Double-Layered Timber Plate
Stiffness
Conference
World Conference on Timber Engineering
Research Status
Complete
Summary
Timber plate structures with integral mechanical attachments have been successfully built in the last decades. Previous research has highlighted the influence of these connections in the global behavior of the structures. Double-layered plate shells are one of the latest applications of integral joints. Their fabrication and assembly has been proven efficient. However, their structural behavior remains unknown. Simplified models are required to predict their behavior since an individual detailed modelling of the large amount of joints would be time-consuming and computationally expensive. Current simplifications involve either considering the connections as rigid or hinged and do not allow accurate prediction of their behavior. In this paper, a numerical finite element model in which the semi-rigid behavior of the joints is modeled by means of springs is presented for a double-layered timber plate structure made of 5 by 3 segments. The numerical model is automatically generated in the finite element software AbaqusTM from a simplified geometry. Numerical results are compared to a three-point bending test performed on two specimens. The developed spring model shows promising results for its application to a full double-layered timber plate shell. Only axial and shear stiffnesses were implemented in this model while the other degrees of freedom were considered rigid. This consideration might lead to an overly stiff model.
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Development of Assembling Large Cross-Section Timber Joint System by High Ductility Wood Frame Structure

https://research.thinkwood.com/en/permalink/catalogue1565
Year of Publication
2016
Topic
Connections
Seismic
Material
LVL (Laminated Veneer Lumber)
Application
Frames
Author
Matsumoto, Shinya
Okamoto, Hajime
Takemoto, Mitsuhiro
Sato, Masanori
Year of Publication
2016
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Application
Frames
Topic
Connections
Seismic
Keywords
Joints
Fiber Reinforced Plastics
Ductility
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 1580-1587
Summary
We propose the high productivity timber joint system based on combining the medium-sized wood lumber as assembly large cross-section member. In general, the wood frame structures are required high ductility performance. In this study, the surfaces of the member joints are covered with fiber reinforced plastics (FRP) to improve the mechanical properties to achieve high ductility wood joints. It will be construction of outstanding architectural space to earthquake resistance by these wood frame structure. The purpose of this study is to investigate the seismic performance of joint and to propose the assembling large cross-section timber joint system by high ductility wood frame structure
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67 records – page 1 of 7.