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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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Behavior of Cross-Laminated Timber Diaphragm Connections with Self-Tapping Screws

https://research.thinkwood.com/en/permalink/catalogue1288
Year of Publication
2018
Topic
Connections
Mechanical Properties
Seismic
Material
CLT (Cross-Laminated Timber)
Author
Sullivan, Kyle
Miller, Thomas
Gupta, Rakesh
Publisher
ScienceDirect
Year of Publication
2018
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Connections
Mechanical Properties
Seismic
Keywords
Seismic Force Resisting System
Monotonic Tests
Cyclic Tests
Strength
Stiffness
Shear Connections
Self-Tapping Screws
Research Status
Complete
Series
Engineering Structures
Summary
Monotonic and cyclic tests were carried out to determine strength and stiffness characteristics of 2.44 m (8 ft) long shear connections with 8 mm and 10 mm diameter self-tapping screws. The goal of this research is tocompare test values of cross-laminated timber (CLT) diaphragm connections in seismic force-resisting systems tothe design values calculated from formulas in the National Design Specification for Wood Construction (USA)and the Eurocode. Understanding and quantifying the behavior of these shear connections will provide structural engineers with increased confidence in designing these components, especially with regard to the seismic forceresisting systems. Ratios of the experimental yield strength (from the yield point on the load-deflection curve) to factored design strength were in the range of 2.1–6.1. In the ASCE 41-13 acceptance criteria analysis, the mfactors for the Life Safety performance level in cyclic tests ranged from 1.6 to 1.8 for surface spline connections and from 0.9 to 1.7 for cyclic half-lap connections. The half-lap connections with a unique combination of angled and vertical screws performed exceptionally well with both high, linear elastic initial stiffness and ductile, postpeak behavior.
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CLT Infill Panels in Steel Moment Resisting Frames as a Hybrid Seismic Force Resisting System

https://research.thinkwood.com/en/permalink/catalogue107
Year of Publication
2013
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Dickof, Carla
Organization
University of British Columbia
Year of Publication
2013
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Keywords
National Building Code of Canada
Timber-Steel Hybrid
Seismic Force Resisting System
Research Status
Complete
Summary
This paper examines CLT-steel hybrid systems at three, six, and nine storey heights to increase seismic force resistance compared to a plain wood system. CLT panels are used as infill in a steel moment frame combining the ductility of a steel moment frame system with a stiffness and light weight of CLT panels. This system allows for the combination of high strength and ductility of steel with high stiffness and light weight of timber. This thesis examines the seismic response of this type of hybrid seismic force resisting system (SFRS) in regions with moderate to high seismic hazard indices. A detailed non-linear model of a 2D infilled frame system and compared to the behavior of a similar plain steel frame at each height. Parametric analysis was performed determining the effect of the panels and the connection configuration, steel frame design, and panel configuration in a multi-bay system. Static pushover loading was applied alongside semi-static cyclic loading to allow a basis of comparison to future experimental tests. Dynamic analysis using ten ground motions linearly scaled to the uniform hazard spectra for Vancouver, Canada with a return period of 2% in 50 years as, 10% in 50 years, and 50% in 50 years to examine the effect of infill panels on the interstorey drift of the three, six, and nine storey. The ultimate and yield strength and drift capacity are determined and used to determine the overstrength and ductility factors as described in the National Building Code of Canada 2010.
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Evaluation of Timber Seismic Force Resisting System in Tall Mass Timber Buildings - Phases 1 & 2

https://research.thinkwood.com/en/permalink/catalogue2191
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Organization
National Research Council Canada
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Keywords
Tall Wood
Seismic Force Resisting System
Research Status
In Progress
Notes
Project contact is Jasmine Wang at the National Research Council Canada
Summary
Currently, only light frame wood-based shearwall and braced and moment-resisting frames are given in the NBC 2015 as acceptable solutions, with the height limit for these SFRSs in high seismic zones being 20 m (6 storeys). There is no acceptable solution for using Timber SFRS in buildings more than 20 m high in high seismic zones. The Tall Wood building projects in Canada have been following the “Alternative Solution” path with supporting test data and analysis that could demonstrate equivalent or better performance than building and fire code or local condition requirements, and were approved on a case-by-case basis by the Authority Having Jurisdiction (AHJ). The Tall Wood projects have been and will be faced with different level of difficulties and challenges depending on the familiarity of AHJ with tall wood construction. Furthermore, there are no consistent procedure and performance criteria to analyze and evaluate the Timber SFRS in tall mass timber buildings that could be referenced by the AHJ. This project is to undertake the work related to: Phase I: development of a Technical Guide with a procedure for evaluation of the seismic performance of Timber SFRS in tall mass timber buildings. Phase II: evaluation of an example solution of Mass Timber SFRS in accordance with the developed Technical Guide as a “Demo” project.
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Experimental Seismic Behavior of a Two-Story CLT Platform Building: Shake Table Testing Results

https://research.thinkwood.com/en/permalink/catalogue2052
Year of Publication
2018
Topic
Seismic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
van de Lindt, John
Amini, Omar
Furley, Jace
Pei, Shiling
Tamagnone, Gabriele
Barbosa, André
Line, Philip
Rammer, Douglas
Fragiacomo, Massimo
Organization
Colorado State University
University of Trieste
Oregon State University
Amarican Wood Council
Forest Products Laboratory
University of L'Aquila
Year of Publication
2018
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Mechanical Properties
Keywords
Shake Table Tests
Full Scale
Service Level Earthquake
Design Base Earthquake
Maximum Considered Earthquake
Seismic Force Resisting System
Conference
World Conference on Timber Engineering
Research Status
Complete
Summary
With the increased usage of Cross Laminated Timber (CLT) in the United States, research efforts have been focused on demonstrating CLT as an effective Seismic Force Resisting System (SFRS). Presented in this paper are the findings of full-scale shake table tests of a two-story 223 m2 (2400 ft2) building with two sets of CLT shear walls on the first and second story. The testing consisted of three phases, each with a unique wall configuration, but only the first phase is presented herein, which consisted of a shear wall with 4:1 aspect ratio CLT panels. The structure was subjected to ground motions scaled to intensities that correspond to a Service Level Earthquake (SLE), Design Base Earthquake (DBE), and Maximum Considered Earthquake (MCE) respectively. In all phases and motions the structure performed well and was in accordance with FEMA collapse prevention requirements for each motion intensity.
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Free
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Large-Scale Dynamic Testing of Rocking Cross Laminated Timber Walls

https://research.thinkwood.com/en/permalink/catalogue2298
Year of Publication
2018
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Walls

Technical Guide for Evaluation of Seismic Force Resisting Systems and Their Force Modification Factors for Use in the National Building Code of Canada with Concepts Illustrated Using a Cantilevered Wood CLT Shear Wall Example

https://research.thinkwood.com/en/permalink/catalogue2804
Year of Publication
2021
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Author
DeVall, Ron
Popovski, Marjan
McFadden, Jasmine
Organization
National Research Council Canada, Canadian Construction Materials Centre
Publisher
National Research Council Canada
Year of Publication
2021
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Topic
Seismic
Keywords
Seismic Force Resisting System
Force Modification Factor
Ductility Factor
Overstrength
Non-linear Dynamic Analysis
National Building Code of Canada
Alternative Design Solution
Shear Walls
Research Status
Complete
Summary
The objective of this guideline is to provide a simple, systematic, and sufficient procedure for evaluating the performance of Seismic Force Resisting Systems (SFRSs) and to determine the appropriate ductilityrelated (Rd) and over-strength related (Ro) force modification factors for implementation in the National Building Code of Canada (NBC). The procedure relies on the application of non-linear dynamic analysis for quantification of the seismic performance of the SFRS. Note that the procedure is also suitable for assessing force modification factors (RdRo values) of systems already implemented in the NBC. The audience for this guideline are those (called the “project study team” in this document) who submit proposals for new SFRSs with defined RdRo values to the NBC for inclusion in Subsection 4.1.8., Earthquake Loads and Effects, of Division B of the NBC. This guideline can also be used by a team performing an alternative design solution for a specific project and seeking acceptance from authority having jurisdiction. In such cases, not all aspects of this guideline (e.g., having different archetypes) will be needed.
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Free
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Wood-Steel Hybrid Seismic Force Resisting Systems: Seismic Ductility

https://research.thinkwood.com/en/permalink/catalogue330
Year of Publication
2012
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Author
Dickof, Carla
Stiemer, Siegfried
Tesfamariam, Solomon
Organization
University of British Columbia
Year of Publication
2012
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Topic
Design and Systems
Keywords
Timber-Steel Hybrid
Overstrength
Ductility
Stiffness
Seismic Force Resisting System
Pushover Response
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
July 15-19, 2012, Auckland, New Zealand
Summary
North American building codes currently provide strict limits on height of wood structures, where for example, in Canada wood structures are limited to 4 or 5 storeys. This paper examines wood-steel hybrid system to increase seismic force resistance beyond current limits, up to 10 storeys. The use wood-steel hybrid systems allows for the combination of high strength and ductility of steel with high stiffness and light weight of timber. This paper examines one type o wood and steel hybrid system: a steel moment frame with infill crossed Laminated Timber (CLT) shear walls. A detailed non-linear model of a 2D wood-steel hybrid seismic force resisting system was completed for 6, and 9 storeys; with two different steel frame designs, and four different placements of the infill walls. The static pushover response of this type of hybrid seismic force resisting system (SFRS) has been completed and compared for all cases. The results indicate that preliminary values for ductility (Rd) and overstrength (Ro) for this type of system are 2.0 and 1.7, respectively, similar to a plain wood wall system. Low ductility frames benefit the most from the addition of CLT shear walls as they do not lose the ductility in the system.
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Free
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8 records – page 1 of 1.