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44 records – page 2 of 5.

Effect of construction features on the dynamic performance of mid-rise CLT platform-type buildings

https://research.thinkwood.com/en/permalink/catalogue3271
Year of Publication
2022
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Author
Ussher, Ebenezer
Gurholt, Carl-Ulrik Dahle
Misalsen, Jonas Næss
Aloisio, Angelo
Tomasi, Roberto
Organization
Università degli Studi dell’Aquila
Publisher
Taylor&Francis Online
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Acoustics and Vibration
Keywords
Buildings
Natural Frequencies
Numerical Model
Research Status
Complete
Series
Wood Material Science & Engineering
Summary
Engineered Wood Products like Cross-Laminated-Timber (CLT) are transforming capabilities of wood as a construction material, enabling architects and engineers to create innovative buildings. Using CLT can have many advantages compared with using traditional materials, not least of which is reducing total superstructure gravitational weights. Reducing gravitational weight can simplify and speed up construction processes and reduce foundation costs. Plus, being made from wood, CLT has desirable ‘green’ credentials like renewability of forest resources and carbon sequestration for the lifespans of buildings. However, like other lightweight structural systems, CLT buildings can be susceptible to high-amplitude motions during ambient or other dynamic force and displacement disturbances. Studies reported here address the dynamic behaviour of mid-rise multi-storey buildings constructed from massive CLT elements, with a focus on predicting lateral modal response characteristics of such buildings. The vehicle for this is detailed Finite Element (FE) models verified as accurate replicators of ambient dynamic motions of completed CLT buildings. Here applications of FE models relate to performances of buildings during seismic events. However, the intent is to also use them to predict motions of buildings during windstorms.
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European Yield Model Exponential Decay Constant Modification for Glulam after Fire Exposure

https://research.thinkwood.com/en/permalink/catalogue3294
Year of Publication
2022
Topic
Fire
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Shakimon, Mohd Nizam
Hassan, Rohana
Malek, Nor Jihan Abd
Zainal, Azman
Awaludin, Ali
Hamid, Nor Hayati Abdul
Lum, Wei Chen
Salit, Mohd Sapuan
Organization
Infrastructure University Kuala Lumpur (IUKL)
University Teknologi MARA
Gadjah Mada University
Universiti Putra Malaysia (UPM)
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Fire
Keywords
Tropical Timber
Glulam Beam
Decay Constant
Finite Element Model
Post-fire
Numerical Model
EYM Modification
Research Status
Complete
Series
Forests
Summary
Many real-scale fire tests have been performed on timber connections to analyze the mechanical behavior of timber connections in previous years. However, little research focused on the bending performance of glued laminated (glulam) timber beam bolted connections after fire exposure. In this paper, the three-dimensional numerical model of the glulam timber beam bolted connections was developed and validated by experimental results. The model can simulate temperature evolution in the connections and their mechanical behavior. In the real-scale test, three (3) samples were prepared for a four-point bending test at normal temperature, while another three (3) samples were tested after exposure to a 30-min standard fire and cooled down to normal temperature. The results show the reduction of the load-carrying capacity before and after exposure to the standard fire by 23.9 kN (71.8%), 8.3 kN (26.1%), and 20.2 kN (47.6%) for bolt diameters of 12 mm, 16 mm, and 20 mm, respectively. The numerical model aims to conduct a parametric study and propose the modification of the exponential decay constant, k, for tropical glulam timber to predict the load-carrying capacity of the glulam timber beam bolted connections after exposure to standard fire.
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Experimental and Numerical Analyses of New Massive Wooden Shear-Wall Systems

https://research.thinkwood.com/en/permalink/catalogue93
Year of Publication
2014
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Author
Pozza, Luca
Scotta, Roberto
Trutalli, Davide
Pinna, Mario
Polastri, Andrea
Bertoni, Paolo
Publisher
MDPI
Year of Publication
2014
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Topic
Seismic
Keywords
Quasi-Static
Cyclic Loading Tests
Numerical model
Ductility
Eurocode 8
Behaviour Factor
Dissipative Capacity
Research Status
Complete
Series
Buildings
Summary
Three innovative massive wooden shear-wall systems (Cross-Laminated-Glued Wall, Cross-Laminated-Stapled Wall, Layered Wall with dovetail inserts) were tested and their structural behaviour under seismic action was assessed with numerical simulations. The wall specimens differ mainly in the method used to assemble the layers of timber boards composing them. Quasi-static cyclic loading tests were carried out and then reproduced with a non-linear numerical model calibrated on the test results to estimate the most appropriate behaviour factor for each system. Non-linear dynamic simulations of 15 artificially generated seismic shocks showed that these systems have good dissipative capacity when correctly designed and that they can be assigned to the medium ductility class of Eurocode 8. This work also shows the influence of deformations in wooden panels and base connectors on the behaviour factor and dissipative capacity of the system.
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FE Analysis of CLT Panel Subjected to Torsion and Verified by DIC

https://research.thinkwood.com/en/permalink/catalogue485
Year of Publication
2013
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Sebera, Václav
Muszynski, Lech
Tippner, Jan
Noyel, Melanie
Pisaneschi, Thomas
Sundberg, Benjamin
Publisher
Springer Netherlands
Year of Publication
2013
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Finite Element Model
Torsion
Numerical model
Digital Image Correlation
Research Status
Complete
Series
Materials and Structures
Summary
The goal of this study was to analyze behavior of the cross-laminated timber (CLT) panel subjected to torsion and develop an efficient procedure for quick verification of numerical model of CLT that subsequently may be used for virtual prototyping of non-standard CLT products. Study used both experiments based on optical measurement using digital image correlation (DIC) and numerical modeling by means of finite element method (FEM). A physical torsion test of the CLT panel was first analyzed in terms of a displacement field that was computed on its surface. The FE simulation of the torsion test followed real boundary conditions and was carried out with use of 2 geometrically different FE models of the CLT. The first FE model did not take into account edgebonding of the lamellas, the second one demonstrated alternative manufacturing option by considering the lamellas’ edge-bonding. The experiment and FE simulations were mutually compared based on displacement paths created on the panel surface. Results showed that the presented procedure offers relatively easy way of verification of FE analyses of CLT. FE model with edge-bonding of lamellas exhibited higher stiffness and higher relative error to DIC measurement than FE model without edge-bonding. Edge-bonding of lamellas introduces influential factor in FE modeling of CLT and should be omitted for accurate and realistic FE analyses of their behavior. Study also showed that lack of orthotropic properties of Oregon hybrid poplar can be in FEA sufficiently substituted by using cottonwood properties. Combining the DIC measurement and FEM in the analysis of the CLT is favorable since it offers an full-field validation of numerical models, which can be subsequently used for virtual prototyping.
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FE Modelling of Notched Connections for Timber-Concrete Composite Structures

https://research.thinkwood.com/en/permalink/catalogue1693
Year of Publication
2016
Topic
Connections
Mechanical Properties
Material
Timber-Concrete Composite
Application
Beams
Floors
Author
Bedon, Chiara
Fragiacomo, Massimo
Year of Publication
2016
Format
Conference Paper
Material
Timber-Concrete Composite
Application
Beams
Floors
Topic
Connections
Mechanical Properties
Keywords
Finite Element Model
Numerical Model
Failure Mechanisms
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4272-4280
Summary
Notched connections are extensively used in timber-concrete (TC) composite beams and floors. Their main advantage is a significantly higher shear strength and stiffness compared to mechanical fasteners. Several mechanical and geometrical aspects, however, should be properly taken into account for design optimization of notched connections, as they strongly affect their structural performance and the corresponding failure mechanisms. In this paper, a preliminary Finite-Element (FE) numerical investigation is carried out by means of full 3D numerical models. The mechanical behaviour of each connection component (e.g. the reinforced concrete topping, the steel coach screw, the timber beam) is properly implemented. Shear or crushing failure mechanisms in the concrete, possible plasticization of the coach screw, as well as longitudinal shear or tension perpendicular to the grain failure mechanisms in the timber beam are taken into account using cohesive elements, damage material constitutive laws and appropriate surface-tosurface interactions. The results of parametric FE studies are compared to experimental data derived from literature, as well as to the results of simplified analytical models, demonstrating that the FE model is capable to capture the experimental behaviour of the connection including the failure mechanisms.
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Finite Element Modeling for Vibration Transmission in a Cross Laminated Timber Structure

https://research.thinkwood.com/en/permalink/catalogue1633
Year of Publication
2016
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Vardaxis, Nikolaos-Georgios
Hagberg, Klas
Bard, Delphine
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Keywords
Sweden
Numerical Model
Finite Element Model
Impact Noise Transmission
Impact Sound
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2953-2962
Summary
This paper deals with a certain type of C.L.T. (Cross Laminated Timber) construction, in a residential building in Fristad, Sweden. The objective is to study impact noise transmission, at the lower frequency range (10-200 Hz), where wooden dwellings perform inefficiently, in terms of acoustic quality. The vibrational behavior of lightweight structures and specifically a multilayered floor separating two vertically adjacent bedrooms are investigated. A numerical model of the multilayered test plate, which includes sound insulation and vibration isolation layers, is developed using the Finite Element Method (F.E.M.) in commercial software. The design process, the analysis and improvement of the calculated outcome concerning accuracy and complexity are of interest. In situ vibration measurements were also performed so as to evaluate the structures dynamic behavior in reality and consequently the validity of the modelled results. The whole process from design to evaluation is discussed thoroughly, where uncertainties of the complex F.E.M. model and the approximations of the real structure are analyzed. Numerical comparisons are presented including mechanical mobility and impact noise transmission results. The overall aim is to set up a template of calculations that can be used as a prediction tool in the future by the industry and researchers.
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Finite Element Modelling of the Cyclic Behaviour of CLT Connectors and Walls

https://research.thinkwood.com/en/permalink/catalogue1653
Year of Publication
2016
Topic
Mechanical Properties
Seismic
Connections
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Aranha, Chrysl
Branco, Jorge
Lourenço, Paulo
Flatscher, Georg
Schickhofer, Gerhard
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Mechanical Properties
Seismic
Connections
Keywords
Shear Tests
Axial Tests
Cyclic Loads
Force-Displacement Curves
Numerical Model
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3533-3540
Summary
The characterization of the behaviour of connectors used in Cross-laminated Timber (CLT) structures is an important aspect that needs to be considered in their seismic design. In this paper, the data from shear and axial tests conducted on connectors have been used to define their force-displacement curves under cyclic loads using the SAWS model in OpenSees. The component curves were then incorporated into the corresponding wall models and the results were compared with their experimental counterparts, in order to determine the validity of the finite element model. Thereby, the non-linear behaviour was restricted to the connectors while the walls themselves were composed of linear orthotropic shell elements. The models were found to provide a good estimate of the initial stiffness and maximum load capacity of the wall specimens. The effects of vertical loading and the presence of openings were determined based on analyses run on the calibrated model.
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Fireproof Tests and Heat Conduction Analyses for Development of 2-Hour Fire Resistant Structures

https://research.thinkwood.com/en/permalink/catalogue1778
Year of Publication
2016
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Kamikawa, Daisuke
Harada, Toshiro
Inada, Tatsuo
Kuratomi, Yoh
Shiozaki, Ikuo
Murata, Tadashi
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Fire
Keywords
Furnace Fire Tests
Calcium Silicate Boards
Gypsum
Fire Resistance
Thickness
Heat Conduction Analysis
Numerical Model
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 5437-5444
Summary
Small furnace fire tests were conducted on CLT cladded with calcium silicate boards, gypsum boards, and combinations of the two. The difference in fire resistance when using different board types, combinations, and thicknesses was demonstrated. Some cross-sectional configurations had enough 2-hour fire resistance performance...
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Fully Reversible Reinforcement of Softwood Beams with Unbonded Composite Plates

https://research.thinkwood.com/en/permalink/catalogue210
Year of Publication
2016
Topic
Design and Systems
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Borri, Antonio
Speranzini, Emanuela
Castori, Giulio
Corradi, Marco
Publisher
ScienceDirect
Year of Publication
2016
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Design and Systems
Mechanical Properties
Keywords
Failure
Flexural Tests
Glass Fiber Reinforced Polymer
Modulus of Rupture
Reinforcement
Softwood
finite element method
Numerical model
Research Status
Complete
Series
Composite Structures
Summary
In this paper, results of flexure tests aimed at improving the structural behavior of softwood beams reinforced with unglued composite plates and at developing an effective alternative to the use of organic resins are presented. The addition of modest ratios of GFRP (Glass Fiber Reinforced Polymer) composite strengthening can prevent tension failure in timber beams. However the application of organic matrices presents problems of reversibility, compatibility and durability with timber and poor performance at high temperatures. The increment in capacity and stiffness and the analysis of the failure modes is the central focus of this paper. The experimental campaign is dealing with a significant number of un-reinforced and reinforced beams strengthened with unbonded GFRP plates. A 3-dimensional finite element model is also presented for simulating the non-linear behavior of GFRP-reinforced softwood beams. The ability of the numerical model to reproduce experimental results for the load–deflection curves is validated.
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Glulam Beams with Holes

https://research.thinkwood.com/en/permalink/catalogue211
Year of Publication
2014
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Jelec, Mario
Varevac, Damir
Zovkic, Jurko
Organization
University of Osijek
Year of Publication
2014
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Mechanical Properties
Keywords
Finite Element Model
Openings
Numerical model
Stress Distribution
Research Status
Complete
Series
e-GFOS
Summary
This paper provides a systematic review of research on glued laminated timber beams with circular and rectangular openings. Experiments on girders with unreinforced openings varied several parameters, including the girder span and shape, opening position and shape, and the relationship between the stress state near the opening and the ratio of opening size to girder size. We compare experimental results with recommendations given by DIN 1052:2004-08, DIN EN 1995-1-1/NA: 2010, prEN 1995-1-1: Final Draft, analytical expressions, and other relevant standards, as well as with the results of numerical models using the finite element method. Because of its myriad complexities and uncertainties, this area remains open for further research and for implementation of that research into practical design guidelines and rules.
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44 records – page 2 of 5.