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13 records – page 1 of 2.

Influence of inter-panel connections on vibration response of CLT floors due to pedestrian-induced loading

https://research.thinkwood.com/en/permalink/catalogue3340
Year of Publication
2023
Topic
Connections
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Milojevic, Marija
Racic, Vitomir
Marjanovic, Miroslav
Nefovska-Danilovic, Marija
Organization
University of Belgrade
Publisher
Elsevier
Year of Publication
2023
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Connections
Acoustics and Vibration
Keywords
Walking Forces
Human-induced Vibrations
Single Surface Spline
Half-lapped Joint
Research Status
Complete
Series
Engineering Structures
Summary
Long-span cross-laminated timber (CLT) floors are typically an assembly of prefabricated CLT panels connected together on the site. The actual connections are commonly neglected in design calculations. Hence, a CLT floor is modelled either as a monolith slab or more frequently as a set of CLT panels with no connections at all. This paper presents a numerical study designed to examine the influence of two most common inter-panel connections, i.e. single surface spline and half-lapped joint, on vibration modes and vibration responses of a range of different CLT floors due to pedestrian-induced loading. Although the inter-panel connections are relatively complex in reality, they are modelled here as an equivalent 2D elastic strip between the CLT panels. This relatively simple yet robust model can be used with ease in design practice, regardless finite element (FE) software used to extract vibration modes of a CLT floor. The corresponding monolith floors and floors without inter-panel connections are studied for the comparison of the results. Vertical vibration responses are simulated for low-frequency and high-frequency floors using the corresponding walking force models given in a popular design guideline for footfall induced vibrations of civil engineering structures. Vibration responses were calculated for single pedestrian occupants and their walking paths parallel and perpendicular to the line of connection. The results showed that including the inter-panel connections in a FE model resulted in up to 2.5 higher RMS acceleration levels. Hence, the common practice of modelling CLT floors as monolith slabs or as a set of panels without connections should be left behind.
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Cost Factor Analysis for Timber–Concrete Composite with a Lightweight Plywood Rib Floor Panel

https://research.thinkwood.com/en/permalink/catalogue3100
Year of Publication
2022
Topic
Cost
Material
Timber-Concrete Composite
Application
Floors
Author
Buka-Vaivade, Karina
Serdjuks, Dmitrijs
Pakrastins, Leonids
Organization
Riga Technical University
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Material
Timber-Concrete Composite
Application
Floors
Topic
Cost
Keywords
Adhesive Connection
Plywood Rib Panel
Floor Vibrations
Rigid Connection
Fibre Reinforced Concrete
Research Status
Complete
Series
Buildings
Summary
With the growing importance of the principle of sustainability, there is an increasing interest in the use of timber–concrete composite for floors, especially for medium and large span buildings. Timber–concrete composite combines the better properties of both materials and reduces their disadvantages. The most common choice is to use a cross-laminated timber panel as a base for a timber–concrete composite. But a timber–concrete composite solution with plywood rib panels with an adhesive connection between the timber base and fibre reinforced concrete layer is offered as the more cost-effective constructive solution. An algorithm for determining the rational parameters of the panel cross-section has been developed. The software was written based on the proposed algorithm to compare timber–concrete composite panels with cross-laminated timber and plywood rib panel bases. The developed algorithm includes recommendations of forthcoming Eurocode 5 for timber–concrete composite design and an innovative approach to vibration calculations. The obtained data conclude that the proposed structural solution has up to 73% lower cost and up to 71% smaller self-weight. Thus, the proposed timber–concrete composite construction can meet the needs of society for cost-effective and sustainable innovative floor solutions.
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A higher-order plate theory for the analysis of vibrations of thick orthotropic laminates

https://research.thinkwood.com/en/permalink/catalogue3204
Year of Publication
2022
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Furtmüller, Thomas
Adam, Christoph
Organization
University of Innsbruck
Publisher
Springer
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Plate Theory
Analytical Solution
Flexural Vibrations
Research Status
Complete
Series
Acta Mechanica
Summary
In this contribution, flexural vibrations of linear elastic laminates composed of thick orthotropic layers, such as cross-laminated timber, are addressed. For efficient computation, an equivalent single-layer plate theory with eight kinematic degrees of freedom is derived, both in terms of equations of motion at the continuum level and in terms of a finite element representation. The validity of the plate theory is demonstrated by comparing natural frequencies of a simply supported plate over a wide frequency range for which an analytical solution is available. Furthermore, the influence of individual material properties on the accuracy of the plate theory is investigated, demonstrating its broad applicability. The influence of material orientation on the accuracy of the plate theory is examined by comparative finite element simulations. It is shown that, for cross-ply laminates, the plate theory is valid for elements oriented at any angle to the material principal axes.
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Lateral stiffening systems for tall timber buildings – tube-in-tube systems

https://research.thinkwood.com/en/permalink/catalogue3268
Year of Publication
2022
Topic
Mechanical Properties
Application
Wood Building Systems
Author
Binck, Charles
Sixie, Alex
Frangi, Andrea
Organization
ETH Zurich
Publisher
Taylor&Francis Online
Year of Publication
2022
Format
Journal Article
Application
Wood Building Systems
Topic
Mechanical Properties
Keywords
Tall Timber Buildings
Tube-in-tube Systems
Wind-induced Vibrations
Moment-resisting Joints
Serviceability Limit State
Research Status
Complete
Series
Wood Material Science & Engineering
Summary
In this paper, an adaptable and architecturally flexible lateral stiffening system for tall timber buildings between 50 and 147 m is developed and investigated. The system is based on a tube-in-tube concept. The internal tube consists of a braced timber core, and the external tube consists of a frame structure with semi-rigid beam-column joints in the façade. Based on a finite element framework, more than 500 000 simulations with different configurations are carried out to assess the performance of the lateral stiffening system subjected to wind loading. The resulting data is used to assess the feasibility of the tube-in-tube system and stiffness requirements for the beam-column joints.
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A theoretical study of the dynamic response of planar timber frames with semi-rigid moment-resisting connections subjected to wind loads

https://research.thinkwood.com/en/permalink/catalogue2960
Year of Publication
2021
Topic
Wind
Application
Frames
Author
Cao, Alex Sixie
Stamatopoulos, Haris
Organization
Norwegian University of Science and Technology
ETH Zurich
Publisher
Elsevier
Year of Publication
2021
Format
Journal Article
Application
Frames
Topic
Wind
Keywords
Moment-resisting Timber Frames
Semi-rigid Connection
Wind-induced Vibrations
Time-domain Analysis
Frequency-domain Analysis
Serviceability
Tall Timber Buildings
Research Status
Complete
Series
Engineering Structures
Summary
The dynamic response of semi-rigid timber frames subjected to wind loads is investigated numerically in this paper. The dynamic response of more than one million unique frames with different parameters was assessed with the frequency-domain gust factor approach, which is currently adopted by Eurocode 1, and the time-domain generalized wind load method. In the generalized wind load method, the frames were simulated for three different wind velocities with five simulations per unique combination of parameters, resulting in more than twelve million simulations in total. Qualitative and quantitative observations of the dataset were made. Empirical expressions for the accelerations, displacements, and fundamental eigenfrequency were proposed by the use of nonlinear regression applied to the obtained numerical results and a frequency reduction factor was developed. The wind-induced accelerations obtained by the two methods were compared to the corresponding serviceability criteria according to ISO10137, providing insight about the feasibility of moment-resisting frames as a lateral load-carrying system for mid-rise timber buildings. Comparison between the theoretical gust factor approach and the generalized wind load method showed that the gust factor approach was nonconservative in most cases. Finally, the effect of uniform and non-uniform mass distributions was investigated, with a theoretical reduction in top-floor accelerations of 50% and 25% respectively.
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Designing Pedestrian Stress-Laminated Timber Bridges for Multiple Spans: Parameters Related to Dynamic Response

https://research.thinkwood.com/en/permalink/catalogue2576
Year of Publication
2019
Topic
Design and Systems
Application
Bridges and Spans
Author
Amundsson, Linnea
Fasth, Sabiha
Organization
Chalmers University of Technology
Year of Publication
2019
Format
Thesis
Application
Bridges and Spans
Topic
Design and Systems
Keywords
SLT
Brigade/PLUS
Eurocode
Vibrations
Eigenfrequency
Damping
Research Status
Complete
Summary
This thesis aims at providing a deeper understanding of the dynamic effects in stress laminated timber bridges. The goal was to develop the dynamic design process for SLT bridges by finding crucial, influencing parameters that affect the acceleration and dynamic behaviour. The studied parameters were, inter alia, span-to-span ratios, damping ratios and density changes. The results showed that the accelerations correlated with multiple parameters and that a lot of improvements can be made in the design process.
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Basis of Design Principles for Timber Structures

https://research.thinkwood.com/en/permalink/catalogue1939
Year of Publication
2018
Topic
Serviceability
Design and Systems
Material
CLT (Cross-Laminated Timber)
Author
Abeysekera, Ishan
Baravalle, Michele
Brandner, Reinhard
Colling, François
Fink, Gerhard
Hamm, Patricia
Hochreiner, Georg
Honfi, Dániel
Ilharco, Tiago
Jockwer, Robert
Kleinhenz, Miriam
Kohler, Jochen
Lawrence, Andrew
Marcroft, Julian
Mikoschek, Michael
Toratti, Tomi
Editor
Fink, Gerhard
Honfi, Dániel
Kohler, Jochen
Dietsch, Philipp
Publisher
COST (European Cooperation in Science and Technology)
Year of Publication
2018
Format
Book/Guide
Material
CLT (Cross-Laminated Timber)
Topic
Serviceability
Design and Systems
Keywords
Eurocode
Deflection
Vibrations
Serviceability Limit States
Eurocode 5
Dowel Type Fastener
Failure Behavior
Research Status
Complete
Summary
This report represents the results of the activities performed in working group 1, Basis of Design. The most important task of working group 1 was the defragmentation and harmonization of techniques and methods that are necessary to prove the reliable, safe and economic application of timber materials or products in the construction industry. This report is structured into five parts. At first general principles regarding the design formats are addressed (Part I). Afterwords timber specific aspects regarding code calibration (Part II) and serviceability (Part III) are summarized. In Part IV other demanding issues for the implementation into Eurocode 5 are addressed. Here also summaries of joint activities with other working groups on cross laminated timber and timber connections are presented. The report concludes with a guideline for data analysis (Part V).
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Guidelines Definition for In-Situ Vibration Measurements of Buildings

https://research.thinkwood.com/en/permalink/catalogue1980
Year of Publication
2018
Topic
Acoustics and Vibration
Material
Timber-Concrete Composite
Application
Floors
Author
Lanata, Francesca
Boudaud, Clément
Amouzou, Kodzo Vioto
Year of Publication
2018
Format
Conference Paper
Material
Timber-Concrete Composite
Application
Floors
Topic
Acoustics and Vibration
Keywords
Vibrations
TCC
Guidelines Definition
Users' Comfort
In-Situ Measurements
Conference
World Conference on Timber Engineering
Research Status
Complete
Summary
As an attempt to find a correlation between dynamic response of timber and timber-concrete composite floors and users’ comfort feeling, an in-situ measurements campaign will be carried out within the framework of a research project started at ESB, France. A large variability of buildings typology, as multi-unit housing, open-space offices and long-span offices with partition walls will be tested. The first experimental experience has shown that choices of means of excitation, type and positioning of sensors, data acquisition device, data analyses methods, depend on the floor configuration. Using in-situ test campaign as a database to compare different measurement protocols and assess the influence of different in-situ conditions, the paper will propose some guidelines for the measurement architecture, the equipment choice and the data analysis to be performed according to each building configuration.
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Vibration Serviceability Design Analysis of Cross-Laminated Timber Floor Systems

https://research.thinkwood.com/en/permalink/catalogue40
Year of Publication
2014
Topic
Acoustics and Vibration
Serviceability
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Ussher, Ebenezer
Sadeghi, Masoud
Weckendorf, Jan
Smith, Ian
Year of Publication
2014
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Acoustics and Vibration
Serviceability
Keywords
Finite Element Model
Floors
Vibrations
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Vibration serviceability of various types of timber floor systems has claimed much attention during past decades. Yet the definition of robustly reliable engineering design approaches has remained elusive, except in well-defined situations. Successful design depends on having appropriate vibration serviceability performance assessment criteria, and ability to predict floor response parameters used by those criteria. This paper addresses prediction of dynamic response characteristics of cross-laminated-timber (CLT) floor systems using finite element methods. Attention is focussed on systems that contain realistic construction features like intra-slab CLT panel to-panel joints, and variations in floor slab edge supports. Modelling assumptions are verified by comparing analytical predictions with test results.
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Efficient Measurement of Elastic Constants of Cross Laminated Timber using Modal Testing

https://research.thinkwood.com/en/permalink/catalogue117
Year of Publication
2014
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Author
Zhou, Jianhui
Chui, Ying Hei
Year of Publication
2014
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Acoustics and Vibration
Keywords
Elasticity
Modal Testing
Modulus of Elasticity
Natural Frequency
Testing
Vibrations
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
It has been shown that measurement of elastic constants of orthotropic wood-based panel products can be more efficiently measured by modal testing technique. Identification of vibration modes and corresponding natural frequencies is key to the application of modal testing technique. This process is generally tedious and requires a number of measurement locations for mode shape identification. In this study, a simplified method for frequency identification was developed which will facilitate the adoption of the vibration-based testing technique for laboratory and industrial application. In the method, the relationship between frequency order and mode order is first studied considering the boundary condition, elastic properties of the orthotropic panel. An algorithm is proposed to predict the frequency values and mode indices based on corresponding normalized sensitivity to elastic constants, initial estimates of orthotropic ratios and measured fundamental natural frequency. The output from the algorithm can be used for identification of sensitive natural frequencies from up to three frequency spectra. Then the algorithm is integrated with the elastic calculation algorithm to extract the elastic constants from the sensitive frequencies. The elastic constants of cross laminated timber panels were measured by the proposed method. The moduli of elasticity agree well with static testing results. The calculated in-plane shear modulus was found to be within the expected range.
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13 records – page 1 of 2.