Skip header and navigation

Refine Results By

605 records – page 1 of 61.

Pinching Effect on Seismic Performance of a SDOF Lightframe Timber Structure

https://research.thinkwood.com/en/permalink/catalogue2542
Year of Publication
2021
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Shear Walls
Author
Eini, Ariya
Zhou, Lina
Ni, Chun
Year of Publication
2021
Country of Publication
Canada
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Shear Walls
Topic
Seismic
Keywords
Pinching Behavior
Energy Dissipation
Hysteresis Loop
Light-frame wood
IDA Analysis
SDOF System
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Summary
Although energy dissipation is one of the key factors in resisting seismic force, current design codes only take into account the ductility of the backbone properties of hysteresis curves, and the energy dissipation is usually not accounted for. This paper focuses on understanding and assessing the influence of energy dissipation due to different pinching levels on the seismic performance of a light-frame wood shear wall system. Timber structures with identical backbone curves but different pinching levels were analyzed. Incremental dynamic analyses were run on a single-degreeof-freedom system with varying pinching stiffness and residual strength. The seismic evaluation is presented by the spectral accelerations causing failure of the structure and the hysteresis energy dissipation under a suite of 22 ground motions (2 components per motion) over a wide range of fundamental periods of typical timber structures. Results show that the effect of pinching on the seismic performance of timber structures is period-dependent. Short period structures are more sensitive to the pinching of hysteresis loops compared to long period structures. The residual strength of pinching loops has a greater influence on the seismic performance than the stiffness of the pinching loops. Hysteretic energy dissipation derived from standard reversed-cyclic tests can provide a better understanding on the seismic resistance of timber structures. However, the hysteretic energy under a seismic event at near-collapse stage neither agrees with quasistatic cyclic test’s energy dissipation nor is well correlated to the maximum seismic capacity of the structure.
Online Access
Free
Less detail

Alternative Load Path Analyses for Mid-Rise Post and Beam Mass Timber Building

https://research.thinkwood.com/en/permalink/catalogue2448
Year of Publication
2020
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Columns
Beams

Combination of Steel Plate Shear Walls and Timber Moment Frames for Improved Seismic Performance

https://research.thinkwood.com/en/permalink/catalogue2735
Year of Publication
2020
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Frames
Author
Iqbal, Asif
Todorov, Borislav
Billah, Muntasir
Year of Publication
2020
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Frames
Topic
Seismic
Keywords
Timber Moment Frames
Steel Plate Shear Walls
Hybrid
Seismic Performance
Interstory Drifts
Language
English
Conference
World Conference on Earthquake Engineering
Research Status
Complete
Summary
Recent interests in adopting sustainable materials and developments in construction technology have created a trend of aiming for greater heights with timber buildings. With the increased height these buildings are subjected to higher level of lateral load demand. A common and efficient way to increase capacity is to use shearwalls, which can resist significant part of the load on the structures. Prefabricated mass timber panels such as those made of Cross-Laminated Timber (CLT) can be used to form the shearwalls. But due to relatively low stiffness value of timber it is often difficult to keep the maximum drifts within acceptable limit prescribed by building codes. It becomes necessary to either increase wall sizes to beyond available panel dimensions or use multiple or groups of walls spread over different locations over the floor plan. Both of the options are problematic from the economic and functional point of view. One possible alternative is to adopt a Hybrid system, using Steel Plate Shear Walls (SPSW) with timber moment frames. The SPSW has much higher stiffness and combined with timber frames it can reduce overall building drifts significantly. Frames with prefabricated timber members have considerable lateral load capacity. For structures located in seismic regions the system possesses excellent energy dissipation ability with combination of ductile SPSW and yielding elements within the frames. This paper investigates combination of SPSW with timber frames for seismic applications. Numerical model of the system has been developed to examine the interaction between the frames and shear walls under extreme lateral load conditions. Arrangements of different geometries of frames and shear walls are evaluated to determine their compatibility and efficiency in sharing lateral loads. Recommendations are presented for optimum solutions as well as practical limits of applications.
Online Access
Free
Resource Link
Less detail

Comparative Study on the Failure of TCC and BCC: A Review

https://research.thinkwood.com/en/permalink/catalogue2750
Year of Publication
2020
Topic
Mechanical Properties
Material
Timber-Concrete Composite
Application
Beams
Author
Deresa, ST
Xu, JJ
Year of Publication
2020
Format
Conference Paper
Material
Timber-Concrete Composite
Application
Beams
Topic
Mechanical Properties
Keywords
Four Point Bending Test
Failure Mode
Bamboo
Language
English
Conference
Structures Congress
Research Status
Complete
Summary
Sustainability is now becoming a major concern in the modern construction industry. Despite being a major economic sector, the construction industry is causing adverse environmental impact. To this end, special attention should be paid to the selection of more "green" construction materials for structural applications. Therefore, a reasonable choice of construction materials can be made on the bases of acceptable structural performance, economic benefits, and sustainability. For instance, the use of composite beams made with traditional concrete and bio-based materials (such as timber and bamboo) is a valuable solution. Timber-Concrete Composite (TCC) beams have been used for decades in various structural applications such as new buildings, refurbishment of old timber structures, and bridges with several environmental benefits. Recently, different researchers proposed composite beams similar to TCC ones but based on engineered bamboo commonly named Bamboo-Concrete Composite (BCC) beams. This study presents comparison of the failure mode of the TCC and BCC beams udder fourpoint bending test. In particular, TCCs beams are compared with BCC ones considering similar shear connectors.
Online Access
Free
Resource Link
Less detail

Deconstructable Timber-Concrete Composite Connectors

https://research.thinkwood.com/en/permalink/catalogue2740
Year of Publication
2020
Topic
Connections
Material
Timber-Concrete Composite
Glulam (Glue-Laminated Timber)
Application
Floors
Author
Derikvand, Mohammad
Fink, Gerhard
Publisher
Society of Wood Science & Technology
Year of Publication
2020
Format
Conference Paper
Material
Timber-Concrete Composite
Glulam (Glue-Laminated Timber)
Application
Floors
Topic
Connections
Keywords
Deconstructable Connections
Deconstructable Connector
TCC
Push-Out Tests
Shear Strength
Slip Modulus
Failure Mode
Self-Tapping Screws
Language
English
Conference
Society of Wood Science and Technology International Convention
Research Status
Complete
Summary
The application of deconstructable connectors in timber-concrete composite (TCC) floors enables the possibility of disassembly and reuse of timber materials at the end of building’s life. This paper introduces the initial concept of a deconstructable TCC connector comprised of a self-tapping screw embedded in a plug made of rigid polyvinyl chloride and a level adjuster made of silicone rubber. This connection system is versatile and can be applied for prefabrication and in-situ concrete casting of TCC floors in both wet-dry and dry-dry systems. The paper presents the results of preliminary tests on the shear performance of four different configurations of the connector system in T-section glulam-concrete composites. The shear performance is compared to that of a permanent connector made with the same type of self-tapping screw. The failure modes observed are also analyzed to provide technical information for further optimization of the connector in the future.
Online Access
Free
Resource Link
Less detail

Design and Performance of High-Rise Structure using Ultra-Lightweight Cross Laminated Timber Floor System

https://research.thinkwood.com/en/permalink/catalogue2698
Year of Publication
2020
Topic
Mechanical Properties
Serviceability
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Ahmed, Danish
Ayadat, Tahar
Asiz, Andi
Publisher
ISEC Press
Year of Publication
2020
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Mechanical Properties
Serviceability
Keywords
Tall Timber Buildings
Lateral Load
Lateral Deflections
Floor Diaphragm
Language
English
Conference
International Structural Engineering and Construction Conference
Research Status
Complete
Series
Proceedings of International Structural Engineering and Construction
Summary
The main objective of this paper is to study the structural performance of a high-rise structure when alternative lightweight material known as cross-laminated timber was used as a slab in floor system in lieu of conventional reinforced concrete slab. A numerical case study was conducted using a highly irregular RC frame building with its two 60-story towers joined at the top. Three major analyses were considered. First, modeling and analyzing the building with an RC slab was conducted to determine the design reference. Second, substituting the RC slab with the CLT slab was performed using the same building skeleton. Third, redesigning and optimizing the building skeleton with that CLT to observe skeleton material saving obtained using the same structural performance criteria. Major lateral loads applicable in the Eastern Province of Saudi Arabia were inputted. Strengths and serviceability requirements for floor diaphragm and lateral load resisting system were checked first before performing a comparative analysis between traditional RC and CLT slabs as floor diaphragm. The structural performance criteria to be used for comparative study between RC and CLT slabs included total drift, inter-story drift due to lateral loads, and base reactions. Structural periods and acceleration responses for each floor were investigated and contrasted with the existing building code. The foundation demand was also investigated based on the structural weight and reactions generated from the RC and CLT floor systems.
Online Access
Free
Resource Link
Less detail

Diagrams for Stress and Deflection Prediction in Cross-Laminated Timber (CLT) Panels with Non-Classical Boundary Conditions

https://research.thinkwood.com/en/permalink/catalogue2719
Year of Publication
2020
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Obradovic, Nikola
Todorovic, Marija
Marjanovic, Miroslav
Damnjanovic, Emilija
Year of Publication
2020
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Stress
Deflection
Eurocode 5
Layerwise Plate Theory
Panels
Language
English
Conference
International Conference on Contemporary Theory and Practice in Construction
Research Status
Complete
Summary
Invention of cross-laminated timber (CLT) was a big milestone for building with wood. Due to novelty of CLT and timber’s complex mechanical behavior, the existing design codes cover only rectangular CLT panels, simply supported along 2 parallel or all 4 edges, making numerical methods necessary in other cases. This paper presents a practical engineering tool for stress and deflection prediction of CLT panels with non-classical boundary conditions, based on the software for the computational analysis of laminar composites, previously developed by the authors. Diagrams applicable in engineering practice are developed for some common cases. The presented methodology could be a basis for more detailed design handbooks and guidelines for various layouts of CLT panels and different types of loadings.
Online Access
Free
Resource Link
Less detail

High Performance Connections to Mitigate Seismic Damage in Cross Laminated Timber (CLT) Structures

https://research.thinkwood.com/en/permalink/catalogue2707
Year of Publication
2020
Topic
Connections
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Author
Smiroldo, Francesco
Gaspari, Andrea
Viel, Davide
Piazza, Maurizio
Year of Publication
2020
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Topic
Connections
Seismic
Keywords
Finite Element Modelling
Non-linear Analysis
Seismic Engineering
Earthquake
Connection Systems
Language
English
Conference
World Conference on Earthquake Engineering
Research Status
Complete
Summary
The present study proposes a new connection system for Cross Laminated Timber (CLT) structures in earthquake prone areas. The system is suitable for creating wall-floor-wall and wall-foundation connections, where each connection device can transfer both shear and tension forces, thus replacing the role of traditional “hold downs” and “angle brackets”, and eliminating possible uncertainty on the load paths and on the force-transfer mechanism. For design earthquakes intensity, the proposed system is designed to remain elastic without accessing the inelastic resources, avoiding in this way permanent deformations in both structural and non-structural elements. However, in case of unforeseen events of exceptional intensity, the system exhibits a pseudo-ductile behaviour, with significant deformation capacity. Furthermore, in the proposed system the vertical forces are directly transferred through the contact between wall panels, avoiding compressions orthogonal to the grain of the floor panels. In this research, the connection system was analysed via finite element modelling based on numerical strategies with different levels of refinements. Nonlinear analyses were performed in order to investigate the response of the connection to shear, tension and a combination of such forces. The numerical responses were compared with those of full-scale experimental tests performed on the proposed connection subjected to different kind of loading configuration. The results appear as promising, suggesting that the proposed connection system could represent a viable solution to build medium-rise seismic-resistant CLT structures, that minimise damage to structural and non-structural elements and the cost of repair.
Online Access
Free
Resource Link
Less detail

Hygrothermal Conditions in Cross Laminated Timber (CLT) Dwellings

https://research.thinkwood.com/en/permalink/catalogue2705
Year of Publication
2020
Topic
Moisture
Energy Performance
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Tingstveit, Merethe
Nielsen, Henrik
Risholt, Birgit
Year of Publication
2020
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Moisture
Energy Performance
Keywords
Hygrothermal
Low-Rise
Residential
Moisture Content
Relative Humidity
Indoor Air Temperature
Language
English
Conference
Nordic Symposium on Building Physics
Research Status
Complete
Summary
The use of CLT has been increasing the last decade, and a subsequently focus on documentation of the accompanying indoor climate and exposed wooden surfaces on human well-being. This study presents the results of a measurement campaign conducted over one year of a CLT apartment building in Grimstad, Norway. The apartment building consists of three floors with 35 apartments and comply with the Norwegian passive house standard and energy grade A. Measurements of the relative humidity (RH), indoor air temperature and wood moisture content (MC) were performed in the exposed CLT spruce panels in three apartments in two different floors. The results from the three apartments show a relatively small variation in the MC values regardless the residents behavior measured as RH variation through a complete year. Selected periods from a cold period (winter) and a warm period (summer) show the variation in relative humidity (RH) and moisture content in the CLT element. However, results from control measurements showed higher MC values. The gap between the measurements and methods are discussed.
Online Access
Free
Resource Link
Less detail

Influence of Openings on the Shear Strength and Stiffness of Cross Laminated Timber (CLT) Panels

https://research.thinkwood.com/en/permalink/catalogue2710
Year of Publication
2020
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls
Shear Walls
Author
Aljuhmani, Ahmad
Ogasawawra, A.
Atsuzawa, E.
Alwashali, Hamood
Shegay, A. V.
Tafheem, Zasiah
Maeda, Masaki
Year of Publication
2020
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Shear Walls
Topic
Mechanical Properties
Keywords
Diagonal Compression Test
Openings
Lateral Strength
In-Plane Shear Stiffness
Panels
Language
English
Conference
World Conference on Earthquake Engineering
Research Status
Complete
Summary
In the last decade, cross laminated timber (CLT) has been receiving increasing attention as a promising construction material for multi-storey structures in areas of high seismicity. In Japan, application of CLT in building construction is still relatively new; however, there is increasing interest in CLT from researchers as well as construction companies. Furthermore, the Japanese government is providing construction cost subsidies for new CLT structures as it is a carbon neutral and sustainable material. The high shear and compressive strength of CLT makes it a good candidate for use as shear walls in mid-rise buildings. One important aspect of CLT walls, and one that is presently poorly understood, is the influence of openings on the shear carrying capacity. Openings are often necessary in CLT panels either in form of windows, doors, lift shaft openings or installation of building services. Concerning this aspect, the code regulations in Japan are relatively strict, such that if openings exceeded certain prescribed limits, the entire CLT panel is considered as a non-structural element, and its contribution to lateral strength is totally ignored. Furthermore, as the maximum opening size is usually governed by edge distance constraints, the size of openings that designers can use is inevitably limited by the standard sizes supplied by the manufacturers. As a result, designers are obligated to adopt very small opening size. This is thought to be a very conservative approach. The main purpose of this paper is to experimentally evaluate the influence of openings on seismic capacity; strength and stiffness reduction, as well as failure mode with changing opening size and opening aspect ratio. In addition, check the validity of the Japanese code regulations with regards to openings in CLT panels. In this study, six 5-layer CLT panels containing different openings were tested. The parameters considered include the size and layout of the opening. The panels were specifically designed with openings that would render them ineffective in resisting lateral loads according to the Japanese standard. However, in addition to the six panels, one panel without openings and one panel with openings that meet the Japanese standard was designed. All the CLT panels were tested in uniaxial diagonal compression in order to simulate pure shear loading. The CLT panels and the loading setup were designed such that the resulting failure mode will be governed by a shear mechanism. The main focus of the experiment was to relate the deterioration of the lateral strength and stiffness of the panels to the size and layout of the opening. The results showed that the panels with openings with the same area have relatively different failure direction and reduction factors for panel shear strength and stiffness, and that is due to the shear weak and strong direction that CLT panels have. Also, the effect of openings on the reduction of stiffness for CLT panels was found to be greater than their effect on the reduction of shear strength. The prescribed equation in the Japanese CLT Guidebook underpredicts stiffness reduction, and has discrepancies with regard to strength as the difference of panel strengths in weak and strong directions are not considered.
Online Access
Free
Resource Link
Less detail

605 records – page 1 of 61.