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Developing Seismic Performance Factors for Cross Laminated Timber in the United States

https://research.thinkwood.com/en/permalink/catalogue124
Year of Publication
2015
Topic
Seismic
Mechanical Properties
Connections
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
van de Lindt, John
Amini, M. Omar
Rammer, Douglas
Line, Philip
Pei, Shiling
Popovski, Marjan
Organization
Canadian Association for Earthquake Engineering
Year of Publication
2015
Country of Publication
Canada
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Seismic
Mechanical Properties
Connections
Keywords
Angle Bracket
Shear Test
Strength
Stiffness
Uplift Test
US
Language
English
Conference
The 11th Canadian Conference on Earthquake Engineering
Research Status
Complete
Notes
July 21-24, 2015, Victoria, BC, Canada
Summary
This paper presents recent progress in the development of seismic performance factors for cross-laminated timber (CLT) systems in the United States. A brief overview of some of other systematic studies conducted in Europe, North America, and Japan is also provided. The FEMA P695 methodology is briefly described and selected results from connector testing and CLT wall testing are discussed. Shear and uplift tests were performed on generic angle brackets to quantify their behavior. CLT walls with these connectors were then tested investigate the influence of various parameters on wall component performance. The influential factors considered include boundary condition, gravity loading, CLT grade, panel thickness, and panel aspect ratio (height:length). Results indicate that boundary condition and gravity loading have beneficial effect on strength and stiffness of the CLT panels. CLT grade is an important parameter while CLT panel thickness only has a minimal influence on wall behavior. Higher aspect ratio (4:1) panels demonstrated less stiffness but considerably more ductility than the panels with lower aspect ratio (2:1). This paper also provides details on some ongoing efforts including additional tests planned, index buildings from which P-695 archetypes will be extracted, and nonlinear modeling for this project.
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Development of Steel-Wood Hybrid Systems for Buildings Under Dynamic Loads

https://research.thinkwood.com/en/permalink/catalogue845
Year of Publication
2012
Topic
Seismic
Design and Systems
Serviceability
Application
Hybrid Building Systems
Author
Stiemer, Siegfried
Tesfamariam, Solomon
Karacabeyli, Erol
Popovski, Marjan
Year of Publication
2012
Country of Publication
Chile
Format
Conference Paper
Application
Hybrid Building Systems
Topic
Seismic
Design and Systems
Serviceability
Keywords
Dynamic Loads
Timber-Steel Hybrid
Strength
Language
English
Conference
International Specialty Conference on Behaviour of Steel Structures in Seismic Areas
Research Status
Complete
Notes
January 9-11, 2012, Santiago, Chile
Summary
A steel-wood hybrid system furnishes not only aesthetically pleasing and sustainable hybrid structures but is superior in seismic applications due to the light weight, high resistance, and adjustable ductility. Such hybrid structural systems are not covered by any material and structural design standards that hinder the general implementation. For light structures, a builder’s guide to hybrid wood and steel connection details already exists in North America. Despite the obvious advantages, however, today’s applications of steel-wood hybrid structures have been limited. Rare hybrid buildings with a concentrically braced frame used for lateral load resistance with a glulam timber floor slab have been built as prototypes. The use of glulam floor slab led to a substantially reduced self-weight, compared with the reinforced concrete slab option. The lighter structure behaves superior in seismic events and has made wind loads the governing design case. The next generation steel-wood hybrid structures should optimally utilize each material. This paper describes a research program of the next generation wood-steel hybrid structures should optimally utilize each material. In detail the following development issues will be addressed: innovative hybrid steel-wood building systems, technical tools to predict structural responses of hybrid systems, design principles underpinning the definition of key code provisions related to strength and serviceability performance of hybrid buildings. It will be highlighted that potential structural problems at the design stage result from material incompatibilities. The constitutive properties of each material, hybrid-material, and joint properties reported in the literature will be used, or supplemented by findings from experimental work.
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Seismic Performance of Embedded Steel Beam Connection in Cross-Laminated Timber Panels for Tall-Wood Hybrid System

https://research.thinkwood.com/en/permalink/catalogue415
Year of Publication
2017
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Author
Zhang, Xiaoyue
Azim, Riasat
Bhat, Pooja
Popovski, Marjan
Tannert, Thomas
Publisher
Canadian Science Publishing
Year of Publication
2017
Country of Publication
Canada
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Topic
Seismic
Keywords
Timber-Steel Hybrid
Energy Dissipation
FFTT
Quasi-Static
Monotonic Test
Reverse Cyclic Test
Failure mechanism
Beam Profiles
Embedment
Language
English
Research Status
Complete
Series
Canadian Journal of Civil Engineering
Summary
Recent developments in novel engineered mass timber products and connection systems have created the possibility to design and construct tall timber-based buildings. This research presents the experiments conducted on the steel-wood connection as main energy dissipating part of a novel steel–timber hybrid system labelled Finding the Forest Through the Trees (FFTT). The performance was investigated using quasi-static monotonic and reversed cyclic tests. The influence of different steel beam profiles (wide flange I-sections and hollow rectangular sections), and the embedment approaches (partial and full embedment) was investigated. The test results demonstrated that appropriate connection layouts can lead to the desired failure mechanism while avoiding excessive crushing of the mass timber panels. The research can serve as a precursos for developing design guidelines for the FFTT systems as an option for tall wood-hybrid building systems in seismic regions.
Copyright
Courtesy of Canadian Science Publishing
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Free
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Post-Tensioned Mass Timber Systems

https://research.thinkwood.com/en/permalink/catalogue1256
Year of Publication
2017
Topic
Design and Systems
Seismic
Application
Frames
Shear Walls
Author
Iqbal, Asif
Popovski, Marjan
Organization
Structures Congress
Publisher
American Society of Civil Engineers
Year of Publication
2017
Country of Publication
United States
Format
Conference Paper
Application
Frames
Shear Walls
Topic
Design and Systems
Seismic
Keywords
North America
New Zealand
Post-Tensioning Cables
Post-Tensioned
Multi-Story
Lateral Load Resisting Systems
High Seismic Regions
Language
English
Conference
Structures Congress 2017
Research Status
Complete
Notes
April 6–8, 2017, Denver, Colorado
Summary
A new type of mass timber structural system has been developed in New Zealand over the last decade. Timber members made of engineered wood products are used in combination with post-tensioning cables to produce highly efficient structural components suitable for multi-story moment resisting frames or shear wall-based lateral load resisting systems. Both systems are particularly useful in structures designed in high seismic regions. The post-tensioning also ensures self-centering of the components and the structural systems after a seismic event. In addition to the post-tensioning, the systems can use energy dissipating devices within the connections that further enhance the ductility of the systems and make them good candidates for low damage structural applications. Extensive experimental and numerical studies have been conducted to determine the performance of these systems and design procedures have been developed for practical applications. In an effort to bring this system closer to the North American designers, this paper contains a summary of the evolution of the concept and the most important research projects and findings to date. In addition, a number of applications within and outside New Zealand are reviewed to demonstrate the applicability of the concept. Finally, potential and recent initiatives for adoption of the technology in North America are discussed.
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Solutions for Upper Mid-Rise and High-Rise Mass Timber Construction: Seismic Performance of Braced Mass Timber Frames, Year 1

https://research.thinkwood.com/en/permalink/catalogue2640
Year of Publication
2019
Topic
Seismic
Design and Systems
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Author
Chen, Zhiyong
Popovski, Marjan
Symons, Paul
Organization
FPInnovations
Year of Publication
2019
Format
Report
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Topic
Seismic
Design and Systems
Keywords
Lateral Load
Seismic Performance
Braced Frames
Language
English
Research Status
Complete
Summary
Braced mass timber (MT) frames are one of the most efficient structural systems to resist lateral loads induced by earthquakes or high winds. Although braced frames are presented as a system in the National Building Code of Canada (NBCC), no design guidelines currently exist in CSA O86. That not only leaves these efficient systems out of reach of designers, but also puts them in danger of being eliminated from NBCC. The main objective of this project was to develop the technical information needed for development of design guidelines for braced MT frames as a lateral load resisting system in CSA O86. In the first year of the project, the seismic performance of thirty (30) braced MT frames with riveted connections with various numbers of storeys, storey heights, and bay aspect ratios were studied by conducting non-linear pushover and dynamic time-history analyses. Also, fifteen (15) glulam brace specimens using bolted connections with different slenderness ratios were tested under monotonic and cyclic loading. Results from this multi-year project will form the basis for developing comprehensive design guidelines for braced frames in CSA O86.
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Seismic Behaviour of Cross-Laminated Timber Structures

https://research.thinkwood.com/en/permalink/catalogue2151
Year of Publication
2012
Topic
Seismic
Connections
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls

Capacity-Based Design for Cross-Laminated Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue1255
Year of Publication
2017
Topic
Mechanical Properties
Connections
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Shear Walls
Author
Shahnewaz, Md
Tannert, Thomas
Alam, Shahria
Popovski, Marjan
Organization
Structures Congress
Publisher
American Society of Civil Engineers
Year of Publication
2017
Country of Publication
United States
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Shear Walls
Topic
Mechanical Properties
Connections
Keywords
In-Plane Stiffness
Strength
Non-Linear Springs
Finite Element Analysis
Hysteretic Behaviour
Cyclic Loading
Language
English
Conference
Structures Congress 2017
Research Status
Complete
Notes
April 6–8, 2017, Denver, Colorado
Summary
The use of cross-laminated timber (CLT) in residential and non-residential buildings is becoming increasingly popular in North America. While the 2016 supplement to the 2014 edition of the Canadian Standard for Engineering Design in Wood, CSAO86, provides provisions for CLT structures used in platform type applications, it does not provide guidance for the in-plane stiffness and strength of CLT shearwalls. The research presented in this paper investigated the in-plane stiffness and strength of CLT shearwalls with different connections for platform-type construction. Finite element analyses were conducted where the CLT panels were modelled as an orthotropic elastic material, and non-linear springs were used for the connections. The hysteretic behaviour of the connections under cyclic loading was calibrated from quasi-static tests; the full model of wall assemblies was calibrated using experimental tests on CLT shearwalls. A parametric study was conducted that evaluated the change of strength and stiffness of walls with the change in a number of connectors. Finally, a capacity-based design procedure is proposed that provides engineers with guidance for designing platform-type CLT buildings. The philosophy of the procedure is to design the CLT buildings such that all non-linear deformations and energy dissipation occurs in designated connections, while all other connections and the CLT panels are designed with sufficient over-strength to remain linear elastic.
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High-Capacity Hold-Down for Tall Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue1529
Year of Publication
2016
Topic
Design and Systems
Seismic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Wood Building Systems
Author
Zhang, Xiaoyue
Popovski, Marjan
Tannert, Thomas
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Hybrid Building Systems
Wood Building Systems
Topic
Design and Systems
Seismic
Mechanical Properties
Keywords
Holz-Stahl-Komposit
Hold-Down
Seismic Load
Strength
Stiffness
Ductility
Failure Mechanisms
Quasi-Static
Monotonic Loading
Reverse Cyclic Loading
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 725-732
Summary
The structural use of wood in North America is dominated by light wood-frame construction used in low-rise and – more recently – mid-rise residential buildings. Mass timber engineered wood products such as laminatedveneer-lumber and cross-laminated timber (CLT) panels enable to use the material in tall and large wood and woodbased hybrid buildings. The prospect of constructing taller buildings creates challenges, one of them being the increasein lateral forces created by winds and earthquakes, thus requiring stronger hold-down devices. This paper summarises the experimental investigation on the performance a high-capacity hold-down for resisting seismic loads in tall timberbased structural systems. The connection consists of the Holz-Stahl-Komposit-System (HSK)™ glued into CLT with the modification that ductile steel yielding was allowed to occur inside the CLT panel. The strength, stiffness, ductility and failure mechanisms of this connection were evaluated under quasi-static monotonic and reversed cyclic loading. The results demonstrate that the modified hold-down-assembly provides a possible solution for use in tall timber-based structures in high seismic zones
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Force Modification Factors for Cross Laminated Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue363
Year of Publication
2012
Topic
Seismic
Market and Adoption
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Pei, Shiling
Popovski, Marjan
van de Lindt, John
Organization
FPInnovations
Year of Publication
2012
Country of Publication
Canada
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Market and Adoption
Keywords
Performance-Based Seismic Design
Canada
US
Force Modification Factors
Mid-Rise
Language
English
Research Status
Complete
Summary
European experience shows that Cross-Laminated Timber (CLT) can be competitive in mid-rise and high-rise buildings. Although this system has not been used to the same extent so far in North America, it can be viable wood structural solution for the shift towards sustainable densification of urban and suburban centers. For these reasons FPInnovations has undertaken a multi-disciplinary project on determining the performance of a typical CLT construction, including quantifying the seismic resistance and force modification factors for CLT buildings in Canada and the US. In this report, a performance-based seismic design (PBSD) of a CLT building was conducted and the seismic response of the CLT building was compared to that of a wood-frame structure tested during the NEESWood project. A suitable force modification factors (R-factors) for CLT mid-rise buildings with different fasteners were recommended for seismic design in Canada and the US. The six-storey NEESWood Capstone building was redesigned as a CLT building using the PBSD procedure developed during the NEESWood project. The results from the quasi-static tests on CLT walls performed at FPInnovations were used as input information for modeling of the main load resisting elements of the structure, the CLT walls. Once the satisfactory design of the CLT mid-rise structure was established through PBSD, a force-based design was developed with varying R-factors and that design was compared to the PBSD result. In this way, suitable R-factors were calibrated so that they can yield equivalent seismic performance of the CLT building when designed using the traditional force-based design methods. Based on the results of this study it is recommended that a value of Rd=2.5 and Ro=1.5 can be assigned for structures with symmetrical floor plans according to NBCC. In the US an R=4.5 can be used for symmetrical CLT structures designed according to ASCE7. These values can be assigned provided that the design values for CLT walls considered (and implemented in the material design standards) are similar to the values determined in this study using the kinematics model developed that includes the influence of the hold-downs in the CLT wall resistance. Design of the CLT building with those R-factors using the equivalent static procedures in the US and Canada will result in the CLT building having similar seismic performance to that of the tested wood-frame NEESWood building, which had only minor non-structural damage during a rare earthquake event.
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Experimental and Numerical Investigation of Novel Steel-Timber-Hybrid System

https://research.thinkwood.com/en/permalink/catalogue81
Year of Publication
2014
Topic
Design and Systems
Seismic
Connections
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Bhat, Pooja
Azim, Riasat
Popovski, Marjan
Tannert, Thomas
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Seismic
Connections
Keywords
Tall Wood
Timber-Steel Hybrid
FFTT
Quasi-Static
Monotonic Testing
Cyclic Testing
Strong-column Weak-beam Failure
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
This paper summarises the experimental and numerical investigation conducted on the main connection of a novel steel-timber hybrid system called FFTT. The component behaviour of the hybrid system was investigated using quasi-static monotonic and reversed cyclic tests. Different steel profiles (wide flange I-sections and hollow rectangular sections) and embedment approaches for the steel profiles (partial and full embedment) were tested. The results demonstrated that when using an appropriate connection layout, the desired strong-column weak-beam failure mechanism was initiated and excessive wood crushing was avoided. A numerical model was developed that reasonably reflected the real component behaviour and can subsequently be used for numerical sensitivity studies and parameter optimization. The research presented herein serves as a precursor for providing design guidance for the FFTT system as an option for tall wood-hybrid buildings in seismic regions.
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10 records – page 1 of 1.