Skip header and navigation

12 records – page 1 of 2.

Dynamic Performance of Timber and Timber-Concrete Composite Flooring Systems

https://research.thinkwood.com/en/permalink/catalogue229
Year of Publication
2013
Topic
Connections
Serviceability
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Author
Rijal, Rajendra
Organization
University of Technology Sydney
Year of Publication
2013
Format
Thesis
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Topic
Connections
Serviceability
Keywords
Connections
Costs
Fasteners
Finite Element Model
Long Span
Multi-Storey
Sustainability
Vibrations
Small Scale
Static Load Tests
Damage Index (DI) Method
Loss of Composite Action Index (LCAI)
Research Status
Complete
Summary
In recent years, there has been an increasing trend in Australia and New Zealand towards the use of long-span timber and timber-concrete composite (TCC) flooring systems for the construction of multi-storey timber buildings. The popularity of these flooring systems is because of their low cost, easy construction and the use of environmentally sustainable materials. Due to their light-weight, such long-span floors are however highly susceptible to vibrations induced by service loads. Although longspan timber and TCC flooring systems can easily be designed to resist the static loads using currently available design guidelines, it is crucial to also investigate the dynamic behaviour of these floors as the occupant discomfort due to excessive vibration may govern the design. Moreover, many structural failures are caused by dynamic interactions due to resonances, which highlight the importance of investigating the dynamic behaviour of flooring systems. To date, there are very limited design guidelines to address the vibration in long-span floors, especially composite floors, due to a lack of sufficient investigation. In 2009, a research consortium named Structural Timber Innovation Company (STIC) was founded, with the aim to address various issues encountered with structural timber buildings including timber and TCC flooring systems. STIC is conducting Research and Development (R & D) work in a number of key areas to provide a new competitive edge for commercial and industrial structural timber buildings. The R & D work is undertaken with three parallel objectives at three universities, namely, the University of Technology Sydney (UTS), the University of Canterbury (UC) and the University of Auckland (UA). The focus of UTS is the assessment of various performance issues of long-span timber only and TCC flooring systems for multi-storey timber buildings. The work presented in this thesis deals with the investigation of the dynamic performance of timber only and TCC flooring systems, which is one of the sub-objectives of the research focus at UTS. In particular, the presented research assesses the dynamic performance of long-span timber and TCC flooring systems using different experimental und numerical test structures. For the experimental investigations, experimental modal testing and analysis is executed to determine the modal parameters (natural frequencies, damping ratios and mode shapes) of various flooring systems. For the numerical investigations, finite element models are calibrated against experimental results, and are utilised for parametric studies for flooring systems of different sizes. Span tables are generated for both timber and TCC flooring systems that can be used in the design of long-span flooring systems to satisfy the serviceability fundamental frequency requirement of 8 Hz or above. For floors where vibration is deemed to be critical, the dynamic assessment using the 8 Hz frequency requirement alone may not be sufficient and additional dynamic criteria such as response factor, peak acceleration and unit load deflection need to be satisfied. To predict the fundamental frequency of various TCC beams and timber floor modules (beams), five different analytical models are utilised and investigated. To predict the cross-sectional characteristics of TCC systems and to identify the effective flexural stiffness of partially composite beams, the “Gamma method” is utilised. Essential input parameters for the “Gamma method” are the shear connection properties (strength, serviceability stiffness and ultimate stiffness) that must be identified. Therefore, a number of experimental tests are carried out using small scale specimens to identify strength and serviceability characteristics of four different types of shear connection systems and three of them were adopted in the TCC beams. The connections included two types of mechanical fasteners (normal wood screw and SFS screw) and two types of notched connectors (bird-mouth and trapezoidal shape) with coach screw. Traditionally, the composite action of a system is determined from static load testing using deflection measurements. However, static load testing is expensive, time consuming and difficult to perform on existing flooring systems. Therefore, two novel methods are developed in this thesis that determines the degree of composite action of timber composite flooring systems using only measurements from non-destructive dynamic testing. The core of both methods is the use of an existing mode-shape-based damage detection technique, namely, the Damage Index (DI) method to derive the loss of composite action indices (LCAIs) named as LCAI1 and LCAI2. The DI method utilises modal strain energies derived from mode shape measurements of a flooring system before and after failure of shear connectors. The proposed methods are tested and validated on a numerical and experimental timber composite beam structure consisting of two LVL components (flange and web). To create different degrees of composite action, the beam is tested with different numbers of shear connectors to simulate the failure of connection screws. The results acquired from the proposed dynamic-based method are calibrated to make them comparable to traditional static-based composite action results. It is shown that the two proposed methods can successfully be used for timber composite structures to determine the composite action using only mode shapes measurements from dynamic testing.
Online Access
Free
Resource Link
Less detail

Evaluation of Timber-Concrete Floor Performance under Occupant-Induced Vibrations using Continuous Monitoring

https://research.thinkwood.com/en/permalink/catalogue131
Year of Publication
2013
Topic
Acoustics and Vibration
Serviceability
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Author
Omenzetter, Piotr
Kohli, Varun
Desgeorges, Yohann
Publisher
Scientific.net
Year of Publication
2013
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Topic
Acoustics and Vibration
Serviceability
Keywords
Damping
Frequencies
Lightweight
Long Span
Office Buildings
Research Status
Complete
Series
Key Engineering Materials
Summary
This paper describes the design of a system to monitor floor vibrations in an office building and an analysis of several months worth of collected data. Floors of modern office buildings are prone to occupant-induced vibrations. The contributing factors include long spans, slender and flexible designs, use of lightweight materials and low damping. As a result, resonant frequencies often fall in the range easily excited by normal footfall loading, creating potential serviceability problems due to undesirable levels of vibrations. This study investigates in-situ performance of a non-composite timber-concrete floor located in a recently constructed innovative multi-storey office building. The floor monitoring system consists of several displacement transducers to measure long-term deformations due to timber and concrete creep and three accelerometers to measure responses to walking forces, the latter being the focus of this paper. Floor response is typically complex and multimodal and the optimal accelerometer locations were decided with the help of the effective independence-driving point residue (EfI-DPR) technique. A novel approach to the EfI-DPR method proposed here uses a combinatorial search algorithm that increases the chances of obtaining the globally optimal solution. Several months worth of data collected by the monitoring system were analyzed using available industry guidelines, including ISO2631-1:1997(E), ISO10137:2007(E) and SCI Publication P354. This enabled the evaluation of the floor performance under real operating conditions.
Online Access
Free
Resource Link
Less detail

Fire Resistance of Long Span Composite Wood Concrete Floor Systems

https://research.thinkwood.com/en/permalink/catalogue17
Year of Publication
2015
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Timber-Concrete Composite
Application
Floors
Author
Ranger, Lindsay
Organization
FPInnovations
Year of Publication
2015
Format
Report
Material
CLT (Cross-Laminated Timber)
Timber-Concrete Composite
Application
Floors
Topic
Fire
Keywords
Long Span
Testing
Full Scale
shear connectors
Research Status
Complete
Summary
There is a need to evaluate timber-concrete composite (TCC) systems under fire conditions to understand how shear connectors will perform and might affect the fire performance and the composite action of the assmebly. This project evaluates the fire performance of TCC assemblies based on their structural resistance, integrity and insulation when exposed to a standard fire, as well as how mass timber and concrete interact. This study involves full-scale fire resistance tests on wood-concrete composite floors using two types of shear connectors.
Online Access
Free
Resource Link
Less detail

Hollow Massive Timber Panels: A High-Performance, Long-Span Alternative to Cross Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue701
Year of Publication
2014
Topic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Floors
Author
Montgomery, William
Organization
Clemson University
Year of Publication
2014
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Floors
Topic
Connections
Mechanical Properties
Keywords
Hollow Massive Timber
Pine
Shear Tests
Screws
Emulsion Polymer Isocyanate
Long Span
Research Status
Complete
Summary
Since the development of Cross Laminated Timber (CLT), there has been a surge in interest in massive timber buildings. Furthermore, recent conceptual and feasibility designs of massive timber towers of 30 or more stories indicate that performance of mass timber structural elements can compete with other building materials in the commercial industry (MGB Architecture and Design et al.). However, in order for massive timber to penetrate the commercial market even further, a solution is needed for long-span massive timber floor systems. Unfortunately, CLT falls short in this area and is unable to span long distances. The hollow massive timber (HMT) panel presented in this thesis offers one potential long-span solution.
Online Access
Free
Resource Link
Less detail

Idaho Central Credit Union Arena – Soaring Roof Demonstrates Mass Timber’s Long-Span Possibilities

https://research.thinkwood.com/en/permalink/catalogue2994
Year of Publication
2022
Topic
General Information
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Publisher
WoodWorks
Year of Publication
2022
Format
Report
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
General Information
Keywords
Case Study
Long Span
Soaring Roof
Life Cycle Assessment
Fire Modeling
Research Status
Complete
Summary
While taller mass timber buildings continue to capture worldwide attention, the University of Idaho chose to pursue a different type of innovation with the Idaho Central Credit Union Arena by showcasing wood’s impressive long-span capabilities. Inspired by the rolling hills of the nearby Palouse, the undulating wood roof of this sports and events facility soars over the open space below, creating a visually stunning structure not typically associated with large arenas. This project is also unique in that it was built through a collaboration of Idaho stakeholders, using wood harvested from the University of Idaho’s Experimental Forest, made into glue-laminated timber (glulam) beams by Idaho manufacturers. “The complex structure makes a strong statement, not only for what mass timber can do, but also for what Idaho’s timber industry can do,” said Lucas Epp, Vice President and Head of Engineering for StructureCraft.
Online Access
Free
Resource Link
Less detail

Innovation in the Design of Cross Laminated Timber for Long Span Floors

https://research.thinkwood.com/en/permalink/catalogue2311
Year of Publication
2015
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Floors

Investigation of a Proposed Long Span Timber Floor for Non-Residential Applications

https://research.thinkwood.com/en/permalink/catalogue197
Year of Publication
2014
Topic
Design and Systems
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Application
Floors
Author
Zabihi, Zhinus
Organization
University of Technology Sydney
Year of Publication
2014
Format
Thesis
Material
LVL (Laminated Veneer Lumber)
Application
Floors
Topic
Design and Systems
Mechanical Properties
Keywords
Commercial
Failure
Long Span
Large Span
Industrial
Short-term
Static Behaviour
Finite element (FE) model
Stress-Strain
Full Scale
Composites
Research Status
Complete
Summary
This PhD research provides a detailed procedure for designing and investigating the short term static behaviour of a proposed long span timber floor system for non-residential applications that meets serviceability and ultimate limit design criteria, with the use of timber as the only structural load bearing part of the system. In this study the behaviour of two types of LVL are investigated through a number of experimental and analytical tests. As a result of the tension and compression tests, a suitable constitutive law is developed which can accurately capture the stress-strain relationship and the failure behaviour of LVL, and it can also be incorporated into FE analysis of any LVL beam with similar structural features to the tested specimens. Further, the results of the full scale four point bending tests on LVL sections are used to identify the behaviour of LVL up to the failure point and to develop a finite element model to capture the behaviour and failure of LVL. Moreover, after investigating the long span timber floors, one system is proposed to be fabricated for the extensive experimental and numerical investigation. The results of the full scale experimental tests together with the numerical investigation provide a robust model for predicting the performance of any timber beams with similar structural features to the proposed system while the dimensions and spans can be varied according to special requirements such as dynamic performance or fire resistance requirements.
Online Access
Free
Resource Link
Less detail

Long-span Timber Roof Structure for the New Feyenoord Stadium

https://research.thinkwood.com/en/permalink/catalogue2575
Year of Publication
2019
Topic
Design and Systems
Material
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
Application
Roofs

Northeastern Species in Hybrid Cross Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue2393
Year of Publication
2019
Topic
Mechanical Properties
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Shear Walls

Timber-Steel-Composite – A Possibility for Hybrid Structures of Long Span Timber Floors

https://research.thinkwood.com/en/permalink/catalogue1697
Year of Publication
2016
Topic
Mechanical Properties
Material
Steel-Timber Composite
Application
Floors
Author
Zimmer, Severin
Augustin, Manfred
Year of Publication
2016
Format
Conference Paper
Material
Steel-Timber Composite
Application
Floors
Topic
Mechanical Properties
Keywords
Four Point Bending Test
Long Span
Bending Stiffness
Full Scale
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4341-4351
Summary
The present contribution deals with the theoretical analysis of a selected geometry of CLT-elements combined with steel trapezoidal cross sections with a subsequent description of test specimens and the results of the conducted four-point-bending test. Used for long span floors this hybrid construction can be adjusted in its bending stiffness as needed. By placing the steel part into the tension zone a ductile failure mode can be achieved as well as notching the trapezoidal cross section is applicable easily. By performing full scale four-point-bending-tests of several test specimens it was possible to confirm the theoretical findings.
Online Access
Free
Resource Link
Less detail

12 records – page 1 of 2.