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28 records – page 1 of 3.

Airborne and impact sound performance of modern lightweight timber buildings in the Australian construction industry

https://research.thinkwood.com/en/permalink/catalogue2948
Year of Publication
2021
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Jayalath, Amitha
Navaratnam, Satheeskumar
Gunawardena, Tharaka
Mendis, Priyan
Aye, Lu
Organization
The University of Melbourne
RMIT University
Publisher
Elsevier
Year of Publication
2021
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Keywords
Impact Sound Transmission
Airborne Sound Transmission
Simulation
Research Status
Complete
Series
Case Studies in Construction Materials
Summary
Timber usage in the Australian construction industry has significantly increased due to its strength, aesthetic properties and extended allowances recently introduced in building codes. However, issues with acoustic performance of lightweight timber buildings were reported due to their inherit product variability and varying construction methods. This article reviews the recent literature on the transmissions of impact and airborne sounds, flanking transmission of timber buildings, and the state of computer prediction tools with reference to the Australian practice. An in-depth analysis of issues and an objective discussion related to acoustic performance of timber buildings are presented. Timber is a lightweight material and shows low airborne sound resistance in low frequency range. Attenuation of sound transmission with addition of mass, layer isolation, different products like cross-laminated timber and prefabrication are discussed. Challenges in measuring sound transmissions and reproducibility of results in low frequency ranges are discussed. Well-defined measurement protocols and refined computer simulation methods are required. The serviceability design criteria for modern lightweight timber applications in Australia need to be re-evaluated in the area of impact generated sound. Developing computer tools to predict airborne and impact sound transmission in lightweight timber buildings is quite challenging as several components such as timber members and complex connections with varying stiffnesses are non-homogeneous by nature. Further, there is a lack of experimentally validated and computationally efficient tools to predict the sound transmission in timber buildings. Computer prediction tools need to be developed with a focus on mid-frequency transmission over flanks and low-frequency transmission of timber and prefabricated buildings.
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A Comparison of the Energy Saving and Carbon Reduction Performance between Reinforced Concrete and Cross-Laminated Timber Structures in Residential Buildings in the Severe Cold Region of China

https://research.thinkwood.com/en/permalink/catalogue1207
Year of Publication
2017
Topic
Energy Performance
Environmental Impact
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Guo, Haibo
Liu, Ying
Meng, Yiping
Huang, Haoyu
Sun, Cheng
Shao, Yu
Publisher
MDPI
Year of Publication
2017
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Energy Performance
Environmental Impact
Keywords
Energy Consumption
Carbon Emissions
Residential
Severe Cold Regions
Simulation
Reinforced Concrete
Life-Cycle Assessment
Research Status
Complete
Series
Sustainability
Summary
This paper aims to investigate the energy saving and carbon reduction performance of cross-laminated timber residential buildings in the severe cold region of China through a computational simulation approach. The authors selected Harbin as the simulation environment, designed reference residential buildings with different storeys which were constructed using reinforced concrete (RC) and cross-laminated timber (CLT) systems, then simulated the energy performance using the commercial software IESTM and finally made comparisions between the RC and CLT buildings. The results show that the estimated energy consumption and carbon emissions for CLT buildings are 9.9% and 13.2% lower than those of RC buildings in view of life-cycle assessment. This indicates that the CLT construction system has good potential for energy saving when compared to RC in the severe cold region of China. The energy efficiency of residential buildings is closely related to the height for both RC and CLT buildings. In spite of the higher cost of materials for high-rise buildings, both RC and CLT tall residential buildings have better energy efficiency than low-rise and mid-rise buildings in the severe cold region of China.
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Decision-Making for Cross-Laminated Timber Modular Construction Logistics Using Discrete-Event Simulation

https://research.thinkwood.com/en/permalink/catalogue2722
Year of Publication
2020
Topic
Site Construction Management
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Abiri, Bahar
Publisher
Oregon State University
Year of Publication
2020
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Site Construction Management
Keywords
Modular Construction
Discrete-Event Simulation
Research Status
Complete
Summary
The two primary considerations for construction project management are budget and time management. Modular construction has the potential to improve construction productivity by minimizing time and costs while improving safety and quality. Cross-Laminated Timber (CLT) panels are beneficial for modular construction due to the high level of prefabrication, adequate dimensional stability, and good mechanical performance that they provide. Accordingly, CLT modular construction can be a feasible way to speed up the construction and provide affordable housing. However, an in-depth study is needed to streamline the logistics of CLT modular construction supply chain management. CLT modular construction can be performed by two primary means based on type of modules produced: panelized (2D) and volumetric (3D). This research aims to help the Architecture, Engineering, and Construction (AEC) industry by developing a tool to assess the impact of various logistical factors on both panelized and volumetric modular construction productivity. Discrete-Event Simulation (DES) models were developed for panelized and volumetric CLT modular construction based on a hypothetical case study and using data collected from superintendents and project managers. Sensitivity analysis is conducted using the developed models to explore the impact of selected manufacturing and logistical parameters on overall construction efficiency. Comparing volumetric and panelized simulations with the same number of off-site crews revealed that the volumetric model has lower on-site process duration while the off-site process is significantly longer. Accordingly, from manufacturing to the final module assembly, the total time for the volumetric model is longer than panelized model. Moreover, the simulations showed that volumetric modular construction is associated with less personnel cost since the main process is performed off-site, which has lower labor costs and a smaller number of crews required on-site. This framework could be used to identify the optimum construction process for reducing the time and cost of the project and aid in decision-making regarding the scale of modularity to be employed for project.
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Design and simulation of an automated robotic machining cell for cross-laminated timber panels

https://research.thinkwood.com/en/permalink/catalogue2966
Year of Publication
2021
Topic
Market and Adoption
Material
CLT (Cross-Laminated Timber)
Author
Villanueva, Emanuel Martinez
Mamledesai, Harshavardhan
Martinez, Pablo
Poostchi, Peyman
Ahmad, Rafiq
Organization
University of Alberta
University of Calgary
Publisher
Elsevier
Year of Publication
2021
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Market and Adoption
Keywords
Automation in Construction
Industrial Design
Offsite Construction
Robotic Simulation
Conference
31st CIRP Design Conference 2021
Research Status
Complete
Series
Procedia CIRP
Summary
Cross-laminated timber (CLT) is an innovative construction material that has brought advantages over traditional wood structures, reducing cost and lead time of buildings in recent years; yet CLT benefits primarily from offsite construction methods instead of automation or safety, while keeping the human onsite. The few advancements in automation for CLT panels have been in the implementation of dedicated CNC machines. Nevertheless, using CNC machines for machining CLT panels have disadvantages like clamping batches of massive panels with individual profiles, lacking the flexibility to access all acute machining angles, and struggling with the extraction of dust while the cutting spindle moves through large tight spaces. These disadvantages can be overcome with industrial robots’ help, which the construction industry has not been traditionally favorable on their application, giving then the research gap in this study. This paper explores the introduction of a robotic cell for the machining of cross-laminated timber panels. The robotic cell is designed using 3D modeling and validated through motion simulation in a virtual environment. The proposed cell design is based on a minimum viable product and compared against a minimum throughput benchmarked on the Canadian market. This study aims to research the feasibility of CLT’s automated machining by providing clear production characteristics of the designed robotic cell, such as material and tool utilization rates, lead time, or production efficiency.
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Design of Timber Members Subjected to Axial Compression or Combined Axial Compression and Bending Based on 2nd Order Theory

https://research.thinkwood.com/en/permalink/catalogue115
Year of Publication
2015
Topic
Design and Systems
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Columns
Author
Frangi, Andrea
Steiger, René
Theiler, Matthias
Organization
International Network on Timber Engineering Research (INTER)
Year of Publication
2015
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Columns
Topic
Design and Systems
Mechanical Properties
Keywords
Bending
Buckling
Codes
Compression
Deformation
Monte Carlo
Simulation
Structural
Testing
Conference
INTER 2015
Research Status
Complete
Notes
August 24-27, 2015, Sibenik, Croatia
Summary
The paper examines the behaviour of structural timber members subjected to axial compression or combined axial compression and bending. Based on experimental and numerical investigations, the accuracy of the existing approach in Eurocode 5 for the design of timber members subjected to axial compression or combined axial compression and bending is assessed and modifications are suggested. By means of extensive experimental investigations, a data base was created for the validation of calculation models and for the assessment of design concepts. In order to assess the behaviour of timber members subjected to axial compression or combined axial compression and bending, strain-based calculation models were developed. The investigations indicate that the existing approach of Eurocode 5 based on 2nd order analysis can lead to an overestimation of the load-bearing capacity. Hence, a modified design approach was developed which agrees with the results of the Monte Carlo simulations very well and thus ensures a safe and economical design of timber members subjected to compression or combined compression and bending.
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Development of a Vibroacoustic Stochastic Finite Element Prediction Tool for a CLT Floor

https://research.thinkwood.com/en/permalink/catalogue2008
Year of Publication
2019
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Floors

Direct Displacement Design of Tall CLT Building with Deformable Diaphragms

https://research.thinkwood.com/en/permalink/catalogue1650
Year of Publication
2016
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Bolvardi, Vahab
Pei, Shiling
van de Lindt, John
Dolan, James
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Seismic
Keywords
Inter-Story Isolation
Displacement-Based Design
Simulation
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3506-3514
Summary
In order to cope with the speed of urbanization around the world especially in areas of high seismicity, researchers and engineers have always been investigating cost-effective building systems with high seismic performance. Cross Laminated Timber (CLT) is a wood based material that is suitable for tall building construction. However, the current CLT system is prone to connection damage in strong earthquakes due to the vast majority of the system ductility resides in connections. One solution is the concept of inter-story isolation to develop a potentially resilient system that can remain damage free during strong earthquakes. A generalized displacement-based design method was developed to design an inter-story isolation system for a tall wood building based on articulated damage expectations. A12-story CLT building with one isolation layer was used to illustrate the proposed design method. The building performance was validated through numerical simulation under different seismic hazard levels.
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Ductile Cross Laminated Timber (CLT) Platform Structures with Passive Damping

https://research.thinkwood.com/en/permalink/catalogue1728
Year of Publication
2016
Topic
Seismic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Hashemi, Ashkan
Loo, Wei Yuen
Masoudnia, Reza
Zarnani, Pouyan
Quenneville, Pierre
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Mechanical Properties
Keywords
Low-Rise
Numerical Model
Reverse Cyclic Loading
Quasi-Static
Simulation
Strength
Slip
Platform Buildings
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4730-4737
Summary
Multi-storey platform cross laminated timber (CLT) structures are becoming progressively desirable for engineers and owners. This is because they offer many significant advantages such as speed of fabrication, ease of construction, and excellent strength to weight ratio. With platform construction, stories are fixed together in a way that each floor bears into load bearing walls, therewith creating a platform for the next level. The latest research findings have shown that CLT platform buildings constructed with traditional fasteners can experience a high level of damage especially in those cases where the walls have adopted hold-down brackets and shear connectors with nails, rivets or screws. Thus, the current construction method for platform CLT structures is less than ideal in terms of damage avoidance. The main objective of this study is to develop a low damage platform timber panelised structural system using a new configuration of slip friction devices in lieu of traditional connectors. A numerical model of such a system is developed for a low rise CLT building and then is subjected to reversed cyclic load simulations in order to investigate its seismic performance. The result of these quasi-static simulations demonstrated that the system maintained the strength through numerous cycles of loading and unloading. In addition to this, the system is capable of absorbing significant amount of energy. The findings of this study demonstrate the proposed concept has the potential to be developed as a low damage seismic solution for CLT platform buildings.
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Energy Saving and Carbon Reduction in the Operation Stage of Cross Laminated Timber Residential Buildings in China

https://research.thinkwood.com/en/permalink/catalogue1208
Year of Publication
2017
Topic
Energy Performance
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Guo, Haibo
Liu, Ying
Chang, Wen-Shao
Shao, Yu
Sun, Cheng
Publisher
MDPI
Year of Publication
2017
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Energy Performance
Keywords
Energy Consumption
Carbon Emissions
Reinforced Concrete
China
Climate Zones
Simulation
Research Status
Complete
Series
Sustainability
Summary
This paper focused on energy consumption and carbon emission for heating and cooling during a building’s operation stage, and examined the energy effects of using Cross Laminated Timber (CLT) as an alternative building material to reinforced concrete (RC) in China’s 31 key cities located in different climate zones. The authors designed two seven-story residential buildings, which were constructed with RC framed and CLT systems, separately. This was followed by simulating the energy consumption using commercialized software IESTM under the different climate zones and calculating the carbon emissions. Comparisons were made between RC and CLT systems buildings on the basis of simulation data. The results show that the estimated energy consumption and carbon emission in CLT buildings are much lower than that of RC buildings in all studied cities, which indicates that CLT systems have good potential in reducing carbon emission and saving energy consumption compared to RC. The energy consumptions and carbon emissions in both concrete and CLT buildings are closely related to the climate zones. Buildings in Severe Cold and Cold Regions consumed the most energy and released more carbon. At the national level, the estimated energy consumption at the operation stage, in the studied building with RC frames and CLT system was approximately 465.1 MJ/m2 and 332.6 MJ/m2 per annum, respectively. Despite vast differences in China’s climate zones, the effects of energy saving and carbon reduction potentials of CLT buildings show little relationship to the climate zone. CLT buildings may result in a weighted 29.4% energy saving, which equals 24.6% carbon reductions, compared with RC buildings at the operation stage at national level, although it may vary in different climate zones.
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Finite-Element-Based Prediction of Moisture-Induced Crack Patterns for Cross Sections of Solid Wood and Glued Laminated Timber Exposed to a Realistic Climate Condition

https://research.thinkwood.com/en/permalink/catalogue2764
Year of Publication
2021
Topic
Moisture
Serviceability
Material
Glulam (Glue-Laminated Timber)
Author
Autengruber, Maximilian
Lukacevic, Markus
Gröstlinger, Christof
Füssl, Josef
Publisher
ScienceDirect
Year of Publication
2021
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Moisture
Serviceability
Keywords
Eurocode 5
Finite Element Simulation
Finite Element Method (FEM)
Failure
Cracks
Load Bearing Capacity
Research Status
Complete
Series
Construction and Building Materials
Summary
Moisture may significantly influence the dimensions and behavior of wooden elements and, thus, it is important to consider within both serviceability as well as ultimate limit state designs. Dimensional changes, also called swelling (during wetting) and shrinkage (during drying), are non-uniform due to the direction-dependent expansion coefficients of wood and usually lead to eigenstresses. If these exceed certain strength values, cracking may occur, which reduces the resistance to external loads, especially to shear stresses. The current standard Eurocode 5 takes these circumstances very simplified into account, by so-called service classes, defined based on the surrounding climate and average moisture levels over the course of a year. Accordingly, reduction factors for strength values and cross section widths are assigned. For a better understanding of the climate-induced changes in wooden beams, we exposed 18 different beams with varying cross sections to a representative climate of Linz, Austria, within the framework of a finite element simulation and investigated the resulting moisture fields and crack patterns. For this purpose, expansions and linear-elastic stresses were simulated by using the thermal and moisture fields obtained in the first simulation step and expansion coefficients. Using a multisurface failure criterion, two critical points in time were determined for each cross section, at which advanced crack simulations were carried out using the extended finite element method. The resulting crack lengths showed that the Eurocode 5 assumption of a linear relationship between crack-free and total width could be verified for both drying and wetting cases. In future, the obtained crack patterns might also be used to investigate the actual reduction of load-bearing capacities of such cross sections, since the position of a crack and, for example, the maximum shear stress may not coincide. For the first time in this work, a consistent concept is presented to estimate the resulting crack formation in a wooden element from any moisture load based on a mechanical well-founded simulation concept. For this reason, this work is intended to lay a basis for a more accurate consideration of climate-related loads on wooden elements up to timber constructions.
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28 records – page 1 of 3.