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7 records – page 1 of 1.

Assessing the Seismic Performance of Screws Used in Timber Structures by Means of Cyclic Bending Tests

https://research.thinkwood.com/en/permalink/catalogue1946
Year of Publication
2018
Topic
Connections
Seismic
Application
Walls
Floors

Behavior of Cross-Laminated Timber Diaphragm Connections with Self-Tapping Screws

https://research.thinkwood.com/en/permalink/catalogue1288
Year of Publication
2018
Topic
Connections
Mechanical Properties
Seismic
Material
CLT (Cross-Laminated Timber)
Author
Sullivan, Kyle
Miller, Thomas
Gupta, Rakesh
Publisher
ScienceDirect
Year of Publication
2018
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Mechanical Properties
Seismic
Keywords
Seismic Force Resisting System
Monotonic Tests
Cyclic Tests
Strength
Stiffness
Shear Connections
Self-Tapping Screws
Language
English
Research Status
Complete
Series
Engineering Structures
Summary
Monotonic and cyclic tests were carried out to determine strength and stiffness characteristics of 2.44 m (8 ft) long shear connections with 8 mm and 10 mm diameter self-tapping screws. The goal of this research is tocompare test values of cross-laminated timber (CLT) diaphragm connections in seismic force-resisting systems tothe design values calculated from formulas in the National Design Specification for Wood Construction (USA)and the Eurocode. Understanding and quantifying the behavior of these shear connections will provide structural engineers with increased confidence in designing these components, especially with regard to the seismic forceresisting systems. Ratios of the experimental yield strength (from the yield point on the load-deflection curve) to factored design strength were in the range of 2.1–6.1. In the ASCE 41-13 acceptance criteria analysis, the mfactors for the Life Safety performance level in cyclic tests ranged from 1.6 to 1.8 for surface spline connections and from 0.9 to 1.7 for cyclic half-lap connections. The half-lap connections with a unique combination of angled and vertical screws performed exceptionally well with both high, linear elastic initial stiffness and ductile, postpeak behavior.
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Behavior of Cross-Laminated Timber Diaphragm Panel-to-Panel Connections with Self-Tapping Screws

https://research.thinkwood.com/en/permalink/catalogue1422
Year of Publication
2017
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Sullivan, Kyle
Organization
Oregon State University
Year of Publication
2017
Country of Publication
United States
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Keywords
Lateral Load Resisting System
Monotonic Tests
Cyclic Tests
Strength
Stiffness
Self-Tapping Screws
International Building Code
Language
English
Research Status
Complete
Summary
The goal of this project is to contribute to the development of design values for cross-laminated timber (CLT) diaphragms in the seismic load-resisting system for buildings. Monotonic and cyclic tests to determine strength and stiffness characteristics of 2.44 m (8 ft) long shear connections with common self-tapping screws were performed. Understanding and quantifying the behavior of these shear connections will aid in developing design provisions in the National Design Specification for Wood Construction and the International Building Code so structural engineers can use CLT more confidently in lateral force-resisting systems and extend the heights of wood buildings. Experimental strength-to-design strength ratios were in the range of 2.1 to 8.7. In the ASCE 41 acceptance criteria analysis, the m-factors for the Life Safety performance level in cyclic tests ranged from 1.6 to 1.8 for surface spline connections and from 0.9 to 1.7 for cyclic half-lap connections. The half-lap connections, where screws were installed in withdrawal, shear, shear, and withdrawal, performed exceptionally well with both high, linear-elastic, initial stiffness, and ductile, post-peak behavior.
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Experimental Test of Cross Laminated Timber Connections Under Bi-Directional Loading

https://research.thinkwood.com/en/permalink/catalogue1551
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls
Shear Walls
Author
Liu, Jingjing
Lam, Frank
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Shear Walls
Topic
Mechanical Properties
Keywords
Shear
Tension
Angle Bracket
Hold-Down
Monotonic Tests
Cyclic Tests
Rocking Walls
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 1223-1232
Summary
This paper presents results of an experimental study of commonly used angle bracket and hold-down connections in Cross Laminated Timber (CLT) wall systems under bi-directional loading. Monotonic and cyclic tests of the connections were carried out in one direction, while different levels of constant force were simultaneously applied in a perpendicular direction. The experiment aims to consider the combined and coupling effect of loads for connections in a rocking CLT shear wall system. Key mechanical characteristics of those connections were calculated, evaluated and discussed. The results show that shear and tension actions for hold-downs are quite independent but strongly coupled for angle brackets. The study gives a better understanding of hysteretic behaviour of CLT connections, and provides reliable data for future numerical analysis of CLT structures.
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Mechanical Characterization of an Innovative Connection System for CLT Structures

https://research.thinkwood.com/en/permalink/catalogue1658
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Angeli, Albino
Polastri, Andrea
Callegari, Ernesto
Chiodega, Manuela
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Self-Tapping Screws
Monotonic Tests
X-RAD
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3581-3590
Summary
This paper presents the numerical-experimental analysis of an innovative connector for CLT structures. The connection system, named X-RAD, has generated a new approach to CLT constructions, characterized by precision and effectiveness. Thanks to the possibility of assembling the X-RAD connectors directly within the factory, the CLT panels can be lifted during the production phases, transported to the construction site and assembled by the use of a sole element represented by the steel elements placed at the corners of the different panels. The X-RAD components in fact are meant to be pre-assembled in the factory by using all-threaded self-tapping screws, so that the system could act as a lifting point for the positioning operations. Several experimental tests are presented and analysed: tests on screws and monotonic tests on different load configurations. The test outcome lead to the mechanical characterization of the connector. X-RAD has been studied also with an analytical approach: the different load configurations have been solved “at limit” condition by the use of equilibrium. The experimental and analytical approach permitted to define respectively the experimental and the analytical capacity domains. Finally a method to verify X-RAD loaded by a generic external load is proposed.
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Screwed Joints in Cross Laminated Timber Structures

https://research.thinkwood.com/en/permalink/catalogue508
Year of Publication
2014
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Flatscher, Georg
Bratulic, Katarina
Schickhofer, Gerhard
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Connections
Mechanical Properties
Keywords
Joints
Cyclic Tests
Monotonic Tests
Screws
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Approximately 60% of all joints in solid timber structures assembled with Cross Laminated Timber (CLT) are realised with screws. Although, the behaviour of axially loaded self-tapping single screws is already well known, only minor experiences are available regarding the behaviour of screwed wall joints. Furthermore, since seismic resistance of CLT structures depends to a great amount on the connections’ ability to dissipate energy, it is important to extend the knowledge on their behaviour more thoroughly. This paper gives a brief overview of the results obtained from experimental monotonic and cyclic tests that were carried out not only on screwed CLT single joints, but also on wall tests with screwed joints. Additionally, the question on modelling the behaviour of a screwed wall joint based on the behaviour of a single screw will be discussed within the present contribution as well. Aforementioned tests are part of an extensive ongoing study investigated at the Graz University of Technology, Institute of Timber Engineering and Wood Technology (TU Graz) and at the competence centre holz.bau forschungs gmbh (hbf).
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State-Of-The-Art Review on Cyclic Behaviour of Connections Used in CLT Multi-Storey Buildings: Test Results and Modelling

https://research.thinkwood.com/en/permalink/catalogue472
Year of Publication
2015
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Branco, Jorge
Sousa, Hélder
Lourenço, Paulo
Ahvenainen, Julia
Aranha, Chrysl
Publisher
Dolnoslaskie Wydawnictwo Edukacyjne (DWE)
Year of Publication
2015
Country of Publication
Poland
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Connections
Mechanical Properties
Keywords
Monotonic Tests
Cyclic Tests
Strength
Damping Ratios
Language
English
Conference
International Conference on Structural Health Assessment of Timber Structures
Research Status
Complete
Notes
September 9-11, 2015, Wroclaw, Poland
Summary
A timber building made of cross-laminated timber (CLT) panels is a modular system where all panels are pre-cut in factory. On site, the single components are then assembled connecting the panels with mechanical fasteners, mainly angle brackets with nails and/or screws, hold-downs, metal plates and self-tapping screws. CLT wall panels are very rigid in comparison to its connections. Thus, connections play an essential role in maintaining the integrity of the structure providing the necessary strength, stiffness and ductility, and consequently, they need close attention by designers. However, there is still a lack of proper design rules for these connections, in particular under cyclic loads, mainly due to a large variety of connectors and connection systems. In this paper, the different properties of connections for CLT buildings, on both monotonic and cyclic behaviour, are described using recent works from different authors. From the bibliography, it is clear that experimental data, regarding both monotonic and cyclic tests, is required for the assessment of the performance of the CLT structural system attending to the interaction between rigid panels and connections. This work evidences results from experimental campaigns and numerical analysis regarding definition and quantification of the cyclic response of CLT connections. Examples regarding monotonic and cyclic tests aimed to evaluate cyclic behaviour of connections through physical parameters, such as the impairment of strength and the damping ratio, are presented and discussed.
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7 records – page 1 of 1.