Skip header and navigation

Refine Results By

  • All Records

2395 records – page 2 of 240.

Acoustic Characteristics of Cross-Laminated Timber Systems

https://research.thinkwood.com/en/permalink/catalogue2618
Year of Publication
2020
Topic
Acoustics and Vibration
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Di Bella, Antonino
Mitrovic, Milica
Publisher
MDPI
Year of Publication
2020
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Design and Systems
Keywords
Wooden Building Technology
Building Acoustics
Noise Control
Flanking Transmission
Energy Efficiency
Sustainability
Research Status
Complete
Series
Sustainability
Summary
The growing diffusion of cross-laminated timber structures (CLT) has been accompanied by extensive research on the peculiar characteristics of this construction system, mainly concerning its economic and environmental benefits, lifecycle, structural design, resistance to seismic actions, fire protection, and energy efficiency. Nevertheless, some aspects have not yet been fully analysed. These include both the knowledge of noise protection that CLT systems are able to offer in relation to the possible applications and combinations of building elements, and the definition of calculation methods necessary to support the acoustic design. This review focuses on the main acoustic features of CLT systems and investigate on the results of the most relevant research aimed to provide key information on the application of acoustic modelling in CLT buildings. The vibro-acoustic behaviour of the basic component of this system and their interaction through the joints has been addressed, as well as the possible ways to manage acoustic information for calculation accuracy improvement by calibration with data from on-site measurements during the construction phase. This study further suggests the opportunity to improve measurement standards with specific reference curves for the bare CLT building elements, in order to compare different acoustic linings and assemblies on the same base. In addition, this study allows to identify some topics in the literature that are not yet fully clarified, providing some insights on possible future developments in research and for the optimization of these products.
Online Access
Free
Resource Link
Less detail

Acoustic emission monitoring of wood materials and timber structures: A critical review

https://research.thinkwood.com/en/permalink/catalogue3187
Year of Publication
2022
Topic
Acoustics and Vibration
Author
Nasir, Vahid
Ayanleye, Samuel
Kazemirad, Siavash
Sassani, Farrokh
Adamopoulos, Stergios
Organization
The University of British Columbia
Mississippi State University
Iran University of Science and Technology
Swedish University of Agricultural Sciences
Publisher
Elsevier
Year of Publication
2022
Format
Journal Article
Topic
Acoustics and Vibration
Keywords
Non-Destructive Evaluation
Acoustic Emission
Structural Health Monitoring
Wood Machining
Kiln Drying
Termite Detection
Thermally Modified Timber
Wood Fracture
Damage Detection
Research Status
Complete
Series
Construction and Building Materials
Summary
The growing interest in timber construction and using more wood for civil engineering applications has given highlighted importance of developing non-destructive evaluation (NDE) methods for structural health monitoring and quality control of wooden construction. This study, critically reviews the acoustic emission (AE) method and its applications in the wood and timber industry. Various other NDE methods for wood monitoring such as infrared spectroscopy, stress wave, guided wave propagation, X-ray computed tomography and thermography are also included. The concept and experimentation of AE are explained, and the impact of wood properties on AE signal velocity and energy attenuation is discussed. The state-of-the-art AE monitoring of wood and timber structures is organized into six applications: (1) wood machining monitoring; (2) wood drying; (3) wood fracture; (4) timber structural health monitoring; (5) termite infestation monitoring; and (6) quality control. For each application, the opportunities that the AE method offers for in-situ monitoring or smart assessment of wood-based materials are discussed, and the challenges and direction for future research are critically outlined. Overall, compared with structural health monitoring of other materials, less attention has been paid to data-driven methods and machine learning applied to AE monitoring of wood and timber. In addition, most studies have focused on extracting simple time-domain features, whereas there is a gap in using sophisticated signal processing and feature engineering techniques. Future research should explore the sensor fusion for monitoring full-scale timber buildings and structures and focus on applying AE to large-size structures containing defects. Moreover, the effectiveness of AE methods used for wood composites and mass timber structures should be further studied.
Online Access
Free
Resource Link
Less detail

Acoustic Emission of Bolt-Bearing Testing on Structural Composite Lumbers

https://research.thinkwood.com/en/permalink/catalogue1443
Year of Publication
2014
Topic
Acoustics and Vibration
Material
LVL (Laminated Veneer Lumber)
OSL (Oriented Strand Lumber)
Author
Du, Yicheng
Zhang, Jilei
Shi, Sheldon
Publisher
Society of Wood Science and Technology
Year of Publication
2014
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
OSL (Oriented Strand Lumber)
Topic
Acoustics and Vibration
Keywords
Acoustic Emission
Bolted Connection
Research Status
Complete
Series
Wood and Fiber Science
Summary
Acoustic emission (AE) characteristics of full-hole bolt-bearing testing on structural compositelumbers (SCL) including laminated veneer lumber (LVL) and oriented strand lumber (OSL) were investigated. The main conclusion is that AE cumulative counts vs time curves of the tested SCL in this study can be characterized with three distinct regions in terms of AE count rates: Region I with a lower constant count rate, Region II with varied and increased count rates, and Region III with a higher constant count rate. Differences in AE count rates of these three regions occurred between LVL and OSL. Also, within each tested SCL, differences in AE count rates were observed among the three regions. These differences in terms of AE count rates between two tested SCL indicate that different types of wood-based composites might have different AE characteristics in terms of the count rate changes when they are subjected to increased bolt compression load. In other words, these differences in AE characteristics between the two tested materials suggest AE “signatures” do exist for SCL bolt connections.
Online Access
Free
Resource Link
Less detail

Acoustic Impact Testing and Waveform Analysis for Damage Detection in Glued Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue771
Year of Publication
2017
Topic
Acoustics and Vibration
Serviceability
Material
Glulam (Glue-Laminated Timber)
Author
Xu, Feng
Wang, Xiping
Teder, Marko
Liu, Yunfei
Publisher
De Gruyter
Year of Publication
2017
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Acoustics and Vibration
Serviceability
Keywords
Decay
Delamination
Damage Detection
Moment Analysis
Wavelet Transform
Acoustic Signals
Research Status
Complete
Series
Holzforschung
Summary
Delamination and decay are common structural defects in old glued laminated timber (glulam) buildings, which, if left undetected, could cause severe structural damage. This paper presents a new damage detection method for glulam inspection based on moment analysis and wavelet transform (WT) of impact acoustic signals. Acoustic signals were collected from a glulam arch section removed from service through impact testing at various locations. The presence and positions of internal defects were preliminarily determined by applying time centroid and frequency centroid of the first moment. Acoustic signals were then decomposed by wavelet packet transform (WPT) and the energy of the sub-bands was calculated as characteristics of the response signals. The sub-bands of 0–375 Hz and 375–750 Hz were identified as the most discriminative features that are associated with decay and delamination and therefore are indicative of the presence of delamination or decay defects. A defect diagnosis algorithm was tested for its ability to identify internal decay and delamination in glulam. The results show that depth of delamination in a glulam member can be determined with reasonable accuracy.
Online Access
Free
Resource Link
Less detail

Acoustic performance of junctions in cross laminated timber constructions

https://research.thinkwood.com/en/permalink/catalogue3097
Year of Publication
2019
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Author
Hörnmark, Jesper
Organization
Chalmers University of Technology
Year of Publication
2019
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Topic
Acoustics and Vibration
Keywords
Mass Timber
Vibration Reduction Index
Flanking Transmission
Research Status
Complete
Summary
With the emergence of cross laminated timber (CLT) as a structural material on the global market, the need to understand the acoustical behavior of buildings constructed with the material grows. CLT faces a set of challenges that concrete or masonry do not; being low density, high in stiffness, sometimes isotropic and sometimes orthotropic depending on the composition. Flanking sound transmission often becomes an issue in the acoustic performance of mass timber buildings. While direct sound transmission can be treated with conventional methods e.g. additional layers, the flanking paths are more complicated to treat since they need to transfer loads over the length of the element. This master’s thesis aims to investigate the flanking paths in cross laminated timber buildings by measuring the structure-borne vibration reduction index (Kij) in realized buildings. The in-field measurements are compared to standardized estimation models and lab measurements published in past research. This thesis finds that standardized estimations underestimate the performance of the examined junctions in low frequencies. The lab measurements are closer to the in-field performance but exaggerate the influence of metal connections and mass-spring behavior of junctions with elastic interlayers. Additionally the theory and results indicates that external loads on the junction play a major role in the resulting performance. Elastic interlayers are not as effective in low levels as in the high levels of any given building, presenting a challenge as mass timber structures are increasingly being built taller.
Online Access
Free
Resource Link
Less detail

Acoustic Performance of Timber and Timber-Concrete Composite Floors

https://research.thinkwood.com/en/permalink/catalogue684
Year of Publication
2014
Topic
Acoustics and Vibration
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Author
Schluessel, Marc
Shrestha, Rijun
Crews, Keith
Year of Publication
2014
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Timber-Concrete Composite
Application
Floors
Topic
Acoustics and Vibration
Keywords
New Zealand
Australia
Building Code of Australia
Sound Insulation
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
A major problem in light-weight timber floors is their insufficient performance coping with impact noise in low frequencies. There are no prefabricated solutions available in Australia and New Zealand. To rectify this and enable the implementation of light-weight timber floors, a structural floor was designed and built in laminated veneer lumber (LVL). The floor was evaluated in a laboratory setting based on its behaviour and then modified with suspended ceilings and different floor toppings. Twenty-nine different floor compositions were tested. The bare floor could not reach the minimum requirement set by the Building Code of Australia (BCA) but with additional layers, a sufficient result of R'w+Ctr 53 dB and L’nT,w + CI 50 dB was reached. Doubling of the concrete mass added a marginal improvement. With concrete toppings and suspended ceiling it is possible to reach the goal in airborne and impact sound insulation. The best result was achieved by combining of additional mass and different construction layers.
Online Access
Free
Resource Link
Less detail

Acoustics and Mass Timber: Room-to-Room Noise Control

https://research.thinkwood.com/en/permalink/catalogue2925
Year of Publication
2018
Topic
Acoustics and Vibration
Application
Floors
Author
McLain, Richard
Organization
WoodWorks
Year of Publication
2018
Format
Report
Application
Floors
Topic
Acoustics and Vibration
Keywords
Mass
Noise Barriers
Decouplers
Floor Topping
Acoustic Mat
Research Status
Complete
Summary
The growing availability and code acceptance of mass timber—i.e., large solid wood panel products such as cross laminated timber (CLT) and nail-laminated timber (NLT)—for floor, wall and roof construction has given designers a low-carbon alternative to steel, concrete, and masonry for many applications. However, the use of mass timber in multi-family and commercial buildings presents unique acoustic challenges. While laboratory measurements of the impact and airborne sound isolation of traditional building assemblies such as light wood-frame, steel and concrete are widely available, fewer resources exist that quantify the acoustic performance of mass timber assemblies. Additionally, one of the most desired aspects of mass timber construction is the ability to leave a building’s structure exposed as finish, which createsthe need for asymmetric assemblies. With careful design and detailing, mass timber buildings can meet the acoustic performance expectations of most building types.
Online Access
Free
Resource Link
Less detail

Acoustics: Sound Insulation in Mid-Rise Wood Buildings

https://research.thinkwood.com/en/permalink/catalogue37
Year of Publication
2014
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Floors
Walls
Author
Schoenwald, Stefan
Zeitler, Berndt
King, Frances
Sabourin, Ivan
Organization
National Research Council of Canada
Year of Publication
2014
Format
Report
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Floors
Walls
Topic
Acoustics and Vibration
Keywords
Acoustics
Mid-Rise
Sound Insulation
Research Status
Complete
Summary
This client report on the acoustics research component regarding sound insulation of elements and systems for mid-rise wood buildings is structured into a main part and four appendices. The main part outlines the background, main research considerations and summarizes conducted research and major outcomes briefly. It is structured like the Acoustics tasks in the Statement of Work of the Mid-rise Wood research project to identify accomplishments. For details on the research, testing and results, the main part references to four appendices that contain more details including test plans, test methods, specimen descriptions and all test data that is vetted so far.
Online Access
Free
Resource Link
Less detail

Acoustics Summary: Sound Insulation in Mid-Rise Wood Building

https://research.thinkwood.com/en/permalink/catalogue750
Year of Publication
2014
Topic
Acoustics and Vibration
Design and Systems
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Wood Building Systems
Author
Schoenwald, Stefan
Zeitler, Berndt
King, Frances
Sabourin, Ivan
Organization
National Research Council of Canada
Year of Publication
2014
Format
Report
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Design and Systems
Keywords
Mid-Rise
Sound Insulation
Impact Sound Transmission
Airborne Sound Transmission
Research Status
Complete
Summary
This report summarizes the acoustics research component regarding sound insulation of elements and systems for the research project on mid-rise and larger wood buildings. The summary outlines the background, main research considerations, research conducted and major outcomes. Further details of the design and the results can found in the appendix of Client Report A1-100035-02.1. The goal of the acoustics research components was to develop design solutions for mid-rise wood and wood-hybrid buildings that comply both with the current National Building Code of Canada (NBCC) 2010 [2] requirements for direct sound insulation and with the anticipated requirements for flanking sound transmission in the proposed, 2015 version of the NBCC. In addition, the design solutions were to provide better impact sound insulation while still achieving code compliance for all other disciplines (interdependencies) as identified in the final report of the scoping study conducted in FY 2010/2011.
Online Access
Free
Resource Link
Less detail

Acoustic Testing and Wood Supply for Framework Office Building in Portland, OR

https://research.thinkwood.com/en/permalink/catalogue1830
Year of Publication
2017
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Floors
Ceilings
Walls
Roofs
Wood Building Systems
Organization
ARUP
StructureCraft
InterTek
Year of Publication
2017
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Floors
Ceilings
Walls
Roofs
Wood Building Systems
Topic
Acoustics and Vibration
Keywords
Sound Transmission
Impact Noise Transmission
Concrete Topping
Research Status
Complete
Series
Framework: An Urban + Rural Design
Summary
Architectural Testing, Inc., an Intertek company (Intertek-ATI), was contracted to conduct airborne sound transmission loss and impact sound transmission tests. The complete test data is included as attachments to this report. The full test specimen was assembled on the day of testing by Intertek-ATI. All materials provided by the client were installed on an existing Intertek-ATI assembly (Cross Laminated Timber - 175 mm) utilizing Intertek-ATI-supplied.
Online Access
Free
Resource Link
Less detail

2395 records – page 2 of 240.