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49 records – page 1 of 5.

Advanced Wood-Based Solutions for Mid-Rise and High-Rise Construction: Structural Performance of Post-Tensioned CLT Shear Walls with Energy Dissipators

https://research.thinkwood.com/en/permalink/catalogue1472
Year of Publication
2018
Topic
Design and Systems
Mechanical Properties
Seismic
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
LSL (Laminated Strand Lumber)
Application
Shear Walls
Author
Chen, Zhiyong
Popovski, Marjan
Symons, Paul
Organization
FPInnovations
Year of Publication
2018
Format
Report
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
LSL (Laminated Strand Lumber)
Application
Shear Walls
Topic
Design and Systems
Mechanical Properties
Seismic
Keywords
Compression Tests
Compression Strength
Energy Dissipation
Post-Tensioned
Pres-Lam
Monotonic Loading
Reverse Cyclic Loading
Research Status
Complete
Summary
The latest developments in seismic design philosophy have been geared towards developing of so called "resilient" or "low damage" innovative structural systems that can reduce damage to the structure while offering the same or higher levels of safety to occupants. One such innovative structural system is the Pres-Lam system that is a wood-hybrid system that utilizes post-tensioned (PT) mass timber components in both rigid-frame and wall-based buildings along with various types of energy disspators. To help implement the Pres-Lam system in Canada and the US, information about the system performance made with North American engineered wood products is needed. That information can later be used to develop design guidelines for the designers for wider acceptance of the system by the design community.Several components influence the performance of the Pres-Lam systems: the load-deformation properties of the engineered wood products under compression, load-deformation and energy dissipation properties of the dissipators used, placement of the dissipators in the system, and the level of post-tensioning force. The influence of all these components on the performance of Pres-Lam wall systems under gravity and lateral loads was investigated in this research project. The research project consisted of two main parts: material tests and system tests.
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An Uplift Friction Damper for Seismically Resilient Mass-Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue2799
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Hybrid Building Systems
Organization
Michigan Technological University
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Hybrid Building Systems
Topic
Design and Systems
Seismic
Keywords
Seismic Force Resisting System
Uplift Friction Damper
Energy Dissipation
Self-Centering
Numerical Model
Tall Wood Buildings
National Earthquake Hazards Reduction Program
Research Status
In Progress
Notes
Project contact is Daniel Dowden at Michigan Technological University
Summary
This award will investigate a low-damage solution for cross-laminated timber (CLT) seismic force-resisting systems (SFRSs) using a novel uplift friction damper (UFD) device for seismically resilient mass-timber buildings. The UFD device will embrace the natural rocking wall behavior that is expected in tall CLT buildings, provide stable energy dissipation, and exhibit self-centering characteristics. Structural repair of buildings with these devices is expected to be minimal after a design level earthquake. Although CLT has emerged as a construction material that has revitalized the timber industry, there exists a lack of CLT-specific seismic energy dissipation devices that can integrate holistically with the natural kinematics of CLT-based SFRSs. CLT wall panels themselves do not provide any measurable seismic energy dissipation. As a payload to the large-scale, ten-story CLT building specimen to be tested on the Natural Hazards Engineering Research Infrastructure (NHERI) shake table at the University of California, San Diego, as part of NSF award 1636164, “Collaborative Research: A Resilience-based Seismic Design Methodology for Tall Wood Buildings,” this project will conduct a series of tests with the UFD devices installed on the CLT building specimen. These tests will bridge analytical and numerical models with the high fidelity test data collected with realistic boundary and earthquake loading conditions. The calibrated models will be incorporated in a probabilistic numerical framework to establish a design methodology for seismically resilient tall wood buildings, leading to a more diverse and eco-sustainable urban landscape. This project will provide local elementary school outreach activities, integrate participation of undergraduate minorities and underrepresented groups into the research activities, and foster graduate level curriculum innovations. Project data will be archived and made available publicly in the NSF-supported NHERI Data Depot (https://www.DesignSafe-CI.org). This award contributes to NSF's role in the National Earthquake Hazards Reduction Program (NEHRP). The research objectives of this payload project are to: 1) bridge the fundamental mechanistic UFD models linking analytical and numerical models necessary for seismic response prediction of seismically resilient CLT-based SFRSs, 2) characterize the fundamental dynamic UFD behavior with validation and calibration through large-scale tests with realistic boundary conditions and earthquake loadings, and 3) integrate low-damage, friction-based damping system alternatives within a resilience-based seismic design methodology for tall wood buildings. To achieve these objectives, the test data collected will provide a critical pathway to reliably establish numerical and analytical models that extend the shake table test results to a broad range of archetype buildings. The seismic performance of mass-timber archetype building systems will be established through collapse risk assessment using incremental dynamic analyses. This will provide a first step in the longer term goal of establishing code-based seismic performance factors for CLT-based SFRSs.
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Buckling-restrained Braced Frames for Seismically Resilient Mass Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue2571
Topic
Seismic
Wind
Application
Frames
Organization
University of Utah
Application
Frames
Topic
Seismic
Wind
Keywords
Buckling Restrained Brace Frames
Resilient Building Design
Mass Timber
Energy Dissipation
Monitoring
Research Status
In Progress
Notes
Project contact is Chris Pantelides at the University of Utah
Summary
A mass timber buckling-restrained braced frame is proposed to enhance the seismic resilience of mass timber buildings. Constructed using wood generated from the national forest system, the mass timber buckling-restrained brace will be integrated with a mass timber frame for structural energy dissipation under seismic or wind loads. The team will improve and optimize the design of structural components based on feedback from a real-time health monitoring system. Outcomes include guidelines for a lateral force resisting system of mass timber buildings in high seismic or wind regions.
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Buildings Made of Dowel-Laminated Timber: Joint and Shear Wall Properties

https://research.thinkwood.com/en/permalink/catalogue1718
Year of Publication
2016
Topic
Mechanical Properties
Seismic
Connections
Material
DLT (Dowel Laminated Timber)
Application
Shear Walls
Author
Sandhaas, Carmen
Year of Publication
2016
Format
Conference Paper
Material
DLT (Dowel Laminated Timber)
Application
Shear Walls
Topic
Mechanical Properties
Seismic
Connections
Keywords
Joints
Load Carrying Capacity
Cyclic Tests
Energy Dissipation
Behaviour Factors
Numerical Models
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4589-4596
Summary
Dowel-laminated timber (DLT) elements consist of lamellae arranged side-by-side that are connected with beech dowels. Due to the glue-free DLT element layup, joints and shear walls potentially suffer from considerable reduction of stiffness and load carrying capacity as metal fasteners inserted perpendicular to the element plane may be placed in gaps between the single lamellae. Tests on typical joints showed that, depending on the fastener diameter, the remaining load carrying capacity of joints in DLT in comparison to joints in solid wood may be only 25%. Tests on DLT shear walls with different sheeting proved that the use of DLT structures as shear walls is only possible if at least one-sided sheeting is used. Cyclic tests on DLT shear walls demonstrated that the DLT construction typology has energy dissipation properties similar to traditional timber frame construction. Analogously, preliminary behaviour factors for DLT buildings evaluated with numerical models were also similar to those for timber frame buildings.
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Comparing Numerical Results for Seismic Performance of Portal Steel Frames Braced with Steel: HSS Brace, Glulam Timber Brace, and Timber-Steel-BRB

https://research.thinkwood.com/en/permalink/catalogue3163
Year of Publication
2022
Topic
Seismic
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Author
Sabbagh-Yazdi, Saeed-Reza
Mirzazadah, Ainullah
Organization
Toosi University of Technology
Editor
Branco, Jorge
Publisher
Hindawi
Year of Publication
2022
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Topic
Seismic
Keywords
Portal Steel Frames
Seismic Analyses
Buckling Restrained Brace
Energy Dissipation
Research Status
Complete
Series
Advances in Civil Engineering
Summary
This study involves the application of timber-based bracings elements. For this purpose, seismic analyses are performed on special portal steel frames without the brace and diagonally braced with Glued Laminated Timber (glulam) and Timber-Steel Buckling Restrained Brace (TS-BRB), and the results are compared with the same configuration using steel Hollow Structural Sections (HSS) bracing, using OpenSees structural analyzer. First, to verify the accuracy of the modeling, the numerical results are compared with experimental measurements on several types of elements: (a) diagonally braced frame with steel Hollow Structural Sections with a concentrically steel braced frame which was tested by the quasi-static method under cyclic loading protocol by previous researchers, (b) diagonally glulam braced frame with results of shake table tests on single-story timber braced frames, and (c) Timber-Steel Buckling Restrained Brace (TS-BRB) frame with experimental results of Heavy Timber Buckling-Restrained Braced Frame (HT-BRB). In the second step, the aforementioned timber base bracing alternatives (glulam, TS-BRB) are applied in the special portal steel frame, then the seismic performance of the frame is investigated under pushover, cyclic, time history, and incremental dynamic analysis (IDA), and then the results are compared with the behavior of similar portal frame in two conditions without the brace and diagonally braced with the steel-HSS brace. Results showed that steel-HSS, glulam, and timber-steel buckling restrained braces have significant roles in energy dissipation, increasing shear capacity, decreasing interstory drift, and decreasing weight and cost of estimation of the structure.
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Controlled Rocking Cross-Laminated Timber Walls for Regions of Low-to-Moderate Seismicity

https://research.thinkwood.com/en/permalink/catalogue1726
Year of Publication
2016
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Kovacs, Mike
Wiebe, Lydell
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Design and Systems
Seismic
Keywords
North America
Canada
Nonlinear Time History Analysis
Prototype
Controlled Rocking Heavy Timber Walls
Drifts
Energy Dissipation
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4671-4680
Summary
Controlled rocking heavy timber walls (CRHTW) were originally developed in New Zealand as a lowdamage seismic force resisting system using Laminated Veneer Lumber (LVL). This paper examines one way of adapting them to regions of low-to-moderate seismicity in North America, using Cross-Laminated Timber (CLT) composed of Canadian timber species. In particular, the adaptation simplifies the CRHTW by omitting supplemental energy dissipation and minimizing the potential for long-term damage to the timber from the post-tensioning. Key assumptions that are used in the design and analysis stages are evaluated with regard to the difference between timber products, and the structural performance of a prototype CRHTW design is confirmed by nonlinear time history analysis. Despite the lack of supplemental energy dissipation, the prototype design performs well with negligible residual drifts and a median peak roof drift of 0.63%. Future research is identified for the continued development of the adapted CRHTW.
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Cross-Laminated Timber Engineering: Improvement and Application

https://research.thinkwood.com/en/permalink/catalogue1366
Year of Publication
2014
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Kramer, Anthonie
Organization
Oregon State University
Year of Publication
2014
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Seismic
Keywords
Poplar
Energy Dissipation
Rocking Walls
Research Status
Complete
Summary
The development of cross-laminated timber (CLT) panel technology has opened up new opportunities for wood in tall buildings. Several characteristics including seismic performance and speed of construction have raised interest among designers. As CLT gains acceptance in the industry, alternative structural solutions need to be investigated to improve performance of CLT as a building material. The first study presented is an assessment of the viability of hybrid poplar for use in CLT panels. Hybrid poplar is a low density species, which is not typically considered for structural applications. Low density species have the potential to improve the structural efficiency of CLT panels. The tests conducted are based on the qualification of panels outlined in the ANSI/APA PRG-320: Standard for Performance-Rated Cross-Laminated Timber to determine the structural viability of the CLT panels. The second study presented is an investigation of a new alternative energy dissipation solution to be used with cross-laminated timber rocking walls for seismic design. The energy dissipators are designed as a structural fuse which can be easily replaced after failure following a large seismic event. The results of this study give insight to alternative solutions for CLT to improve upon current applications.
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Cyclic Load Behaviour of Beam-to-Column Glulam Joints Combining Glued-in Rods with Steel Brackets

https://research.thinkwood.com/en/permalink/catalogue2028
Year of Publication
2018
Topic
Connections
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Ling, Zhibin
Liu, Weiqing
Yang, Huifeng
Xiang, Zhe
Year of Publication
2018
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Connections
Mechanical Properties
Keywords
Beam-to-Column
Joints
Glued-In Rods
Steel Brackets
Cyclic Loading
Monotonic Loading
Failure Modes
Stiffness
Ductility
Energy Dissipation
Hysteresis Loop
Douglas-Fir
Conference
World Conference on Timber Engineering
Research Status
Complete
Summary
This paper presents an experimental campaign conducted on the beam-to-column glulam joints combing glued-in rods and steel brackets (BCGS glulam joints) aiming to investigate the mechanical behaviour of these glulam joints under low cyclic loading. Three types of steel brackets were designed for connecting the beam and column combing with glued-in rods and to work as energy dissipaters. In each group of specimens (except for group MJ4), two specimens were tested under monotonic loading and the others were subjected to low cyclic loading. The test results were summarized comprehensively in terms of failure modes, joint stiffness, hysteresis loops, ductility and energy dissipation ability. Generally, the difference of load capacity between BCGS glulam joints and the beam-to-column glulam joints only with glued-in rods (BCG glulam joints) was not significant. The joint stiffness of BCG glulam joints was higher than that of the BCGS glulam joints, while the stiffness degradation of the later is slower than the former. The hysteresis loops of the BCGS glulam joints exhibited less pinching effect obviously compared with the BCG glulam joints, which indicated that the energy dissipation ability of the glulam joints with glued-in rods could be improved significantly by using the steel brackets as energy dissipaters. Moreover, it should be noted that the hysteresis loops of groups CJ1 showed slipping effect obviously during testing. This might due to the insufficient shear resistance of these two groups, so that further investigations on BCG glulam joints with shear-resisting components are urgently needed.
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Design and Testing of Post-Tensioned Timber Wall Systems

https://research.thinkwood.com/en/permalink/catalogue696
Year of Publication
2014
Topic
Design and Systems
Seismic
Material
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
Application
Walls
Author
Sarti, Francesco
Palermo, Alessandro
Pampanin, Stefano
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
Application
Walls
Topic
Design and Systems
Seismic
Keywords
Multi-Storey
Pres-Lam
Energy Dissipation
Quasi-Static Test
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
The paper presents the design and detailing, and the experimental quasi-static 2/3 scale tests of two post-tensioned wall systems: a single (more traditional) wall system and a new configuration comprising of a column-wall-column coupled system. The latter allows avoiding displacement incompatibilities issues between the wall and the diaphragm by using the boundary columns as supports.
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Displacement Design Procedure for Cross Laminated Timber (CLT) Rocking Walls with Sacrificial Dampers

https://research.thinkwood.com/en/permalink/catalogue395
Year of Publication
2015
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Gu, Mengzhe
Pang, Weichiang
Schiff, Scott
Organization
Structures Congress
Publisher
American Society of Civil Engineers
Year of Publication
2015
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Design and Systems
Seismic
Keywords
Energy Dissipation
Ductile Behavior
U-Shaped Flexural Plates
Self-centering Mechanism
Conference
Structures Congress 2015
Research Status
Complete
Notes
April 23–25, 2015, Portland, Oregon, USA
Summary
This paper presents the preliminary design of a rocking Cross-laminated Timber (CLT) wall using a displacement-based design procedure. The CLT wall was designed to meet three performance expectations: immediate occupancy (IO), life safety (LS), and collapse prevention (CP). Each performance expectation is defined in terms of an inter-story drift limit with a predefined non-exceedance probability at a given hazard level. U-shape flexural plates were used to connect the vertical joint between the CLT panels to obtain a ductile behavior and adequate energy dissipation during seismic motion. A design method for ensuring self-centering mechanism is also presented.
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49 records – page 1 of 5.