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21 records – page 1 of 3.

Bucking Performance of CLT Composed of 3 Layer-3 Ply

https://research.thinkwood.com/en/permalink/catalogue944
Year of Publication
2015
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Tanaka, Kei
Hiroishi, Taro
Mohri, Takumi
Yuheiri, Mouri
Nakahata, Takumi
Harada, Hiroshi
Inoue, Masafumi
Organization
Architectural Institute of Japan
Year of Publication
2015
Country of Publication
Japan
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Bucking
Compression
Bending Stiffness
Language
Japanese
Research Status
Complete
Summary
The present paper evaluate slaminatedcarbonbi-wove fibers Reinforced with vinyl ester composites. Vinyl ester was used as a matrix to prepare composites by in situ polymerization technique. Four planar layers were made simultaneously by keeping one over the other and each layer made sure to be weighed off by 15% which was maintained in all layers with different orientations. Pre-assumed Layer-1 is (50/50)50%,0º; Layer-2 is (35/35/30) 35% 0º, 35% +45º,30%,0;Layer-3is (25/50/25) 25% 0º, 50%+45º,25-45º; and Layer-4is (25/25/25/25) (25% 0º, 25% +45º,25% -45º,25% 90º.The composite was prepared with the help of hand layup technique. Test ready specimens were tested with the help of shearing machine in accordance with ASTM Standards .It was observed that vinyl ester made good interface with parent fiber material. Flexural strength and Tensile strength have improved up to 3rd layer and decreased afterwards whereas Flexural modulus and Tensile modulus have linearly increased up to 4th layer. Thermal stability and Glass transition temperature have also been found to be satisfactory for all the laminated layers. Chemical resistance was good for the entire chemicals except sodium hydroxide.
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Effect of Opening on Seismic Performance of CLT Panel: Part. 1 Shear Test of H-Shape Specimen Panel

https://research.thinkwood.com/en/permalink/catalogue943
Year of Publication
2015
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Ishiro, Taro
Mohri, Takumi
Yuheiri, Mouri
Nakahata, Takumi
Suzuki, Kei
Harada, Hiroshi
Mori, Takuro
Tanaka, Kei
Kaiko, Naoto
Inoue, Masafumi
Organization
Architectural Institute of Japan
Year of Publication
2015
Country of Publication
Japan
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Keywords
Shear Test
Opening
Language
Japanese
Research Status
Complete
Summary
A concrete-filled steel tube (CFT) column system has many advantages compared with ordinary sttel or reinforced concrete system. One of the main advantages is the interaction between steel tube and concrete: occurrence of the local buckling of steel tube is delayed by the restraint of concrete, and the strength of concrete is increased by the confining effect provided from the steel tube. Extensive research work has been done in Japan over the last 15 years, including "New Urban Housing Project" and "US-Japan Cooperative Earthquake Research Program", in addition to the work done by individual universities and industries, which has been presented at the annual meeting of Architectural Institute of Japan (AIJ). This paper introduces the merits, design provisions and recent construction trends of CFT column systems in Japan, and discusses the results of trial designs of CFT theme structures which have been carried out to look for the advantages in the performance and construction cost compared with other constructional system.
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Effect of Opening on Seismic Performance of CLT Panel: Part. 2 Bending Shear Test of L-Shape Specimen Panel

https://research.thinkwood.com/en/permalink/catalogue942
Year of Publication
2015
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Mohri, Takumi
Ishiro, Taro
Yuheiri, Mouri
Nakahata, Takumi
Suzuki, Kei
Harada, Hiroshi
Mori, Takuro
Tanaka, Kei
Kaiko, Naoto
Inoue, Masafumi
Organization
Architectural Institute of Japan
Year of Publication
2015
Country of Publication
Japan
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Keywords
Bending Test
Shear
Opening
Language
Japanese
Research Status
Complete
Summary
The paper presents some experimental data and phenomenon on bracket anchor connections for Cross-Laminated-Timber. The goal of this research is to provide a better understanding of the seismic performance of bracket connections subjected to seismic actions and how to choose and design bracket connections for Cross-Laminated-Timber structures. Test configuration and experimental setups are illustrated in details; cyclic displacement schedules of the connections in two directions are presented considering that CLT wall has horizontal sliding in the plane and uplift at the end in quasi-state tests. Different failure modes and force transmission mechanisms of different connections under the loading protocol were analysed. And important quantities for seismic design such as strength, and stiffness, equivalent yield load, peak load and ductility of the connections are evaluated and compared among different kinds of connections; an excellent connector is revealed in ductility and load capacity by test data analysis. In addition, some suggestions to choose and design bracket anchor connections are given.
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Development of Steel Frame and Timber Floor System: Part 2. An Experimental Study on Flexural Performance of CLT Floor Encased Reinforcement Bars

https://research.thinkwood.com/en/permalink/catalogue949
Year of Publication
2014
Topic
Design and Systems
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Kuratomi, Kohitaka
Inada, Tatsuo
Fujii, Hideyuki
Organization
Architectural Institute of Japan
Year of Publication
2014
Country of Publication
Japan
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Design and Systems
Mechanical Properties
Keywords
Bending Test
Reinforcement
Language
Japanese
Research Status
Complete
Summary
Low-damage seismic-resistant post-tensioning technologies were first developed during the PREcast Seismic Structural Systems program, coordinated by the University of California San Diego. Different connections were developed and tested as part of the research program, and the most stable solution was the hybrid connection, which provides a combination of re-centering and dissipative contributions. The hybrid connection was later extended to Laminated Veneer Lumber Elements (LVL) and referred to as Pres-Lam (Prestressed Laminated) system. As part of a broader experimental campaign on frame and walls systems, several experimental tests were carried out on small-scale specimens of post-tensioned single walls and on coupled walls systems. More recently 2/3 scale quasistatic tests were performed on different wall configurations. The paper shows the evaulation of the seismic performance factors of post-tensioned timber wall systems, carried out according to the FEMA P695 procedure. The latter utilizes nonlinear analysis techniques, and explicitly considers uncertainties in ground motion, modelling, design, and test data. The technical approach is a combination of traditional code concepts, advanced nonlinear dynamic analyses, and risk-based assessment techniques. A set of archetype buildings were developed to characterize the behaviour of the system. Several parameters were accounted for, such as the building height, lateral load resisting system, magnitude of the gravity loads and seismic design category. The system archetypes were represented by numerical models developed to simulate the full range of behavioural aspects of the system. Nonlinear quasi-static and dynamic analyses were carried out to determine the system over-strength factors and median collapse capacity of the buildings. The system performance was then assessed by computing the Collapse Margin Ratio (CMR) defined as the ratio of the median collapse (SCT) and MCE (SMT) spectral accelerations.Once the non-linear analysis results confirmed the CMR values were within acceptable values, the trial value of the seismic response modification, R, was confirmed, and the system seismic performance factors were evaluated.
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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.
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Tensile Performance of CLT Screw Joint with Steel Plate

https://research.thinkwood.com/en/permalink/catalogue1010
Year of Publication
2014
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Nakajima, Shoichi
Araki, Yasuhiro
Goto, Hiroshi
Nakajima, Shiro
Yamaguchi, Yoshinobu
Yasumura, Motoi
Organization
Architectural Institute of Japan
Year of Publication
2014
Country of Publication
Japan
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Screws
Joints
Steel Plate
Tensile Performance
Laminar Boundary
Cyclic Loading
Language
Japanese
Research Status
Complete
Summary
The wood engineering community has dedicated a significant amount of effort over the last decades to establish a reliable predictive model for the load-carrying capacity of timber connections under wood failure mechanisms. Test results from various sources (Foschi and Longworth 1975; Johnsson 2003; Quenneville and Mohammad 2000; Stahl et al. 2004; Zarnani and Quenneville 2012a) demonstrate that for multi-fastener connections, failure of wood can be the dominant mode. In existing wood strength prediction models for parallel to grain failure in timber connections using dowel-type fasteners, different methods consider the minimum, maximum or the summation of the tensile and shear capacities of the failed wood block planes. This results in disagreements between the experimental values and the predictions. It is postulated that these methods are not appropriate since the stiffness in the wood blocks adjacent to the tensile and shear planes differs and this leads to uneven load distribution amongst the resisting planes (Johnsson 2004; Zarnani and Quenneville 2012a). The present study focuses on the nailed connections. A closed-form analytical method to determine the load-carrying capacity of wood under parallel-to-grain loading in small dowel-type connections in timber products is thus proposed. The proposed stiffness-based model has already been verified in brittle and mixed failure modes of timber rivet connections (Zarnani and Quenneville 2013b).
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Dynamic Analysis of Large-Scale Wooden Structures with a Core of Reinforced Concrete and Considering Wooden Diaphragm Stiffness : Part1. Background and Analysis Models

https://research.thinkwood.com/en/permalink/catalogue876
Year of Publication
2013
Topic
Design and Systems
Application
Hybrid Building Systems
Author
Asakawa, Takeshi
Kano, Daisuke
Organization
Architectural Institute of Japan
Year of Publication
2013
Country of Publication
Japan
Format
Journal Article
Application
Hybrid Building Systems
Topic
Design and Systems
Keywords
Mid-Rise
Timber-Concrete Hybrid
Language
Japanese
Research Status
Complete
Summary
The purpose of this paper is to outline the foundation for the research by presenting the underlying design philosophy and resulting design framework that will serve as the basis for the emerging design methodology. In this way, context will be provided for the technical papers to follow and the eventual design methodology at the project’s conclusion. A companion paper, “Seismic Design Methodology for Precast Concrete Diaphragms—Part 2: Research Program,” describes the specific analytical and experimental activities taking place in the research.
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Dynamic Analysis of Large-Scale Wooden Structures with a Core of Reinforced Concrete and Considering Wooden Diaphragm Stiffness : Part2 Results of Response Analysis and Studies

https://research.thinkwood.com/en/permalink/catalogue875
Year of Publication
2013
Topic
Design and Systems
Application
Hybrid Building Systems
Author
Kano, Daisuke
Asakawa, Takeshi
Organization
Architectural Institute of Japan
Year of Publication
2013
Country of Publication
Japan
Format
Journal Article
Application
Hybrid Building Systems
Topic
Design and Systems
Keywords
Mid-Rise
Timber-Concrete Hybrid
Language
Japanese
Research Status
Complete
Summary
The purpose of this paper is to outline the foundation for the research by presenting the underlying design philosophy and resulting design framework that will serve as the basis for the emerging design methodology. In this way, context will be provided for the technical papers to follow and the eventual design methodology at the project’s conclusion. A companion paper, “Seismic Design Methodology for Precast Concrete Diaphragms—Part 2: Research Program,” describes the specific analytical and experimental activities taking place in the research.
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Impedance Characteristics in Wooden Frames Structure Using Large Dimension Glued Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue994
Year of Publication
2013
Topic
Acoustics and Vibration
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Author
Yoda, Takuya
Inoue, Katsuo
Tomita, Ryuta
Okura, Yasuhiko
Organization
Architectural Institute of Japan
Year of Publication
2013
Country of Publication
Japan
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Topic
Acoustics and Vibration
Keywords
Impact Sound
Language
Japanese
Research Status
Complete
Summary
Recent years have witnessed an increased use of glued timber products in construction, due to their highlights in versatility and sustainability. It is therefore a demanding necessity to develop non-destructive integrity assessment methods for structural health monitoring of timber constructions, both during production and utilization. Particularly, the integrity and load bearing capacity of the glue line need to be tested. Air coupled ultrasound (ACU) is a novel non-destructive method which is well suited for this purpose. The advantages with respect to traditional ultrasonic contact techniques are phenomenal reproducibility and unlimited scanning capabilities, together with full preservation of the properties of the inspected object. As part of an on-going project in the Swiss Federal Laboratories for Materials Testing and Research (Empa) together with the Laboratory for Wood Physics and Non-Destructive Testing Methods of ETH Zuerich, experiments were performed in samples consisting of two layers of glued laminated timber with artificially introduced delaminations. First, the main ultrasound propagation phenomena were modelled with dedicated analytical calculations and numerical simulations. Next the samples were scanned with a precise mechanical system and a Normal Transmission Mode setup and the ACU waveforms were digitized for each scanned position. A specific amplitude tracking algorithm together with a self-calibration procedure applied to the ultrasonic images were used to compensate for ultrasonic amplitude variations induced by wood heterogeneity. The mean amplitude variations in the orthotropic R-T plane and in the L axis were of 10 and 5 dB respectively. After an appropriate wood heterogeneity correction the uncertainty in the R-T plane was reduced down to 4 dB. Adhesion defects were reliably assessed for the investigated samples, as well in situations where adhesive was present in the glue line but no bonding existed between timber lamellas (dry glue), or where the adhesive spread during the pressing in an uncontrolled way to the desired non-glued regions. The ACU results were validated with an also novel Micro Focus Computed Tomography glue line assessment method. Specific wave propagation phenomena depending on the year ring orientation with respect to the insonification direction were also discussed.
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21 records – page 1 of 3.