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Development and Testing of an Alternative Dissipative Posttensioned Rocking Timber Wall with Boundary Columns

https://research.thinkwood.com/en/permalink/catalogue1884
Year of Publication
2016
Topic
Seismic
Design and Systems
Application
Frames
Walls
Author
Sarti, Francesco
Palermo, Alessandro
Pampanin, Stefano
Publisher
American Society of Civil Engineers
Year of Publication
2016
Format
Journal Article
Application
Frames
Walls
Topic
Seismic
Design and Systems
Keywords
Pres-Lam
Prestress
Post-Tensioning
Displacement
Seismic Performance
Column-Wall-Column
Research Status
Complete
Series
Journal of Structural Engineering
Summary
The unbonded post-tensioned rocking and dissipative technology was first developed as the main outcome of the PRESSS (PREcast Seismic Structural Systems) Program in US. After the first developments and significant refinement, the technology was extended to steel and, more recently, timber structures. The timber version, referred to as Pres-Lam (Prestressed laminated) system can be either implemented for timber walls (single or coupled) or frames or combination of the above, with unbonded post-tensioning and supplemental dissipation devices. In unbonded post-tensioned dissipative wall systems a combination of re-centering capacity and energy dissipation leads to a “controlled rocking” mechanism which develops a gap opening at the wall base. This generates an uplift displacement which is transferred to the floor diaphragm. This vertical displacement incompatibility can represent a potential issue if the connection detailing between floor and lateral resisting system is not designed properly. The same issue can be mitigated by adopting an alternative configuration of the rocking/dissipative wall system, based on the use of a column-wall-column post-tensioned connection. This concept, originally proposed for precast concrete walls and referred to as PreWEC (Prestressed Wall with End Column), has been extended and adapted to posttensioned timber structures and validated through experimental testing. The paper presents the design, detailing and experimental testing of a two-thirds scale wall specimen of this alternative configuration. Different wall configurations are considered in terms of post-tensioning initial force as well as dissipation devices layout. The experimental results confirm the excellent seismic performance of the system with the possibility to adopt multiple alternative configurations.
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Development of a Heavy Timber Moment-Resisting Frame with Ductile Steel Links

https://research.thinkwood.com/en/permalink/catalogue1657
Year of Publication
2016
Topic
Connections
Mechanical Properties
Seismic
Material
Solid-sawn Heavy Timber
Application
Frames
Author
Gohlich, Ryan
Erochko, Jeffrey
Year of Publication
2016
Format
Conference Paper
Material
Solid-sawn Heavy Timber
Application
Frames
Topic
Connections
Mechanical Properties
Seismic
Keywords
Mid-Rise
Self-Tapping Screws
Moment-Resisting
Strength
Stiffness
Ductility
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3571-3580
Summary
To improve the seismic performance of mid-rise heavy timber moment-resisting frames, a hybrid timbersteel moment-resisting connection was developed that incorporates specially detailed replaceable steel yielding link elements fastened to timber beams and columns using self-tapping screws (STS). Performance of the connection was verified using four 2/3 scale experimental tests. The connection reached a moment of 142 kN m at the column face while reaching a storey drift angle of 0.05 rad. Two specimens utilizing a dogbone detail in the steel link avoided fracture of the link, while two specimens absent of the dogbone detail underwent brittle failure at 0.05 rad drift. All four test specimens met the acceptance criteria in the AISC 341-10 provisions for steel moment frames. The STS connections exhibited high strength and stiffness, and all timber members and self-tapping screw connections remained elastic. The results of the experimental program indicated that this hybrid connection is capable of achieving a ductility factor similar to that of a steel-only moment-resisting connection. This research suggests that the use of high ductility factors in the design of timber systems that use the proposed hybrid connection would be appropriate, thus lowering seismic design base shears and increasing structure economy.
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Development of Assembling Large Cross-Section Timber Joint System by High Ductility Wood Frame Structure

https://research.thinkwood.com/en/permalink/catalogue1565
Year of Publication
2016
Topic
Connections
Seismic
Material
LVL (Laminated Veneer Lumber)
Application
Frames
Author
Matsumoto, Shinya
Okamoto, Hajime
Takemoto, Mitsuhiro
Sato, Masanori
Year of Publication
2016
Format
Conference Paper
Material
LVL (Laminated Veneer Lumber)
Application
Frames
Topic
Connections
Seismic
Keywords
Joints
Fiber Reinforced Plastics
Ductility
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 1580-1587
Summary
We propose the high productivity timber joint system based on combining the medium-sized wood lumber as assembly large cross-section member. In general, the wood frame structures are required high ductility performance. In this study, the surfaces of the member joints are covered with fiber reinforced plastics (FRP) to improve the mechanical properties to achieve high ductility wood joints. It will be construction of outstanding architectural space to earthquake resistance by these wood frame structure. The purpose of this study is to investigate the seismic performance of joint and to propose the assembling large cross-section timber joint system by high ductility wood frame structure.
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Development of CLT Panels Bond-in Method for Seismic Retrofitting of RC Frame Structure

https://research.thinkwood.com/en/permalink/catalogue1860
Year of Publication
2016
Topic
Seismic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Walls
Frames
Author
Haba, Ryota
Kitamori, Akihisa
Mori, Takuro
Fukuhara, Takeshi
Kurihara, Takaaki
Isoda, Hiroshi
Publisher
J-STAGE
Year of Publication
2016
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Walls
Frames
Topic
Seismic
Design and Systems
Keywords
Retrofit
Earthquake
Panels
Adhesive
Bonding
Research Status
Complete
Series
Journal of Structural and Construction Engineering: Transactions of AIJ
Summary
In this paper, the new type of seismic retrofit method using CLT panels as shear walls is proposed. In this method, setting small CLT panels in RC frame and bonding each panel and panel to RC frame with epoxy resin, panels compose shear walls. The advantages of this technique are: There are less dust, noise, and vibration during construction; Light weight panels enable easy construction and short construction period; Light weight panels also cause small seismic force. In this research, cyclic loading tests for 5 types of reinforced specimens and 2 types of plain RC frames as control were conducted. The stress analysis showed that the bond strength between CLT and RC and shear modulus of CLT in these specimens match the result of element tests. So the specimen strength could be divided into the RC frame strength and the CLT strength until the initial deformation. As the bond strength between CLT and RC was smaller than the shear strength of CLT, the specimens can be stronger by increasing the adhesive area.
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Development of Timber Buckling Restrained Brace for Mass Timber-Braced Frames

https://research.thinkwood.com/en/permalink/catalogue3242
Year of Publication
2021
Topic
Mechanical Properties
Application
Frames
Author
Murphy, Colton
Pantelides, Chris P.
Blomgren, Hans-Erik
Rammer, Douglas
Organization
University of Utah
Katerra
Forest Products Laboratory
Publisher
ASCE
Year of Publication
2021
Format
Journal Article
Application
Frames
Topic
Mechanical Properties
Keywords
Brace
Buckling
Buckling Restrained Braced Frame
Damping
Fuse
Research Status
Complete
Series
Journal of Structural Engineering
Summary
This research presents the development of a mass timber buckling restrained brace (T-BRB) that combines a low yield strength steel core with a mass timber casing to create a new ductile fuse. The T-BRB is an essential element of a mass timber buckling restrained braced frame (BRBF), which is a promising mass timber wood lateral force–resisting system. Critical elements of T-BRB design that are important for good performance include casing stiffness, casing material, number and spacing of bolts, timber spacer and casing gap, steel core yield strength, and friction between steel core and casing interface. Compressive tests on engineered wood blocks using glued laminated timber, laminated veneer lumber, parallel strand lumber, and mass plywood panel (MPP) were conducted to determine elastic stiffness, maximum load, and ultimate displacement. MPP loaded parallel to the wide face of laminations (X-direction) outperformed other materials with respect to high elastic stiffness, which is an important property of the casing because it controls buckling of the steel core. Six 3.66 m (12 ft)–long T-BRBs with a targeted yield strength of 274 kN (61.5 kip) were tested utilizing three T-BRB casing designs with varying MPP lamination layups. A 3.9% strain was achieved under a strain-based loading protocol. For a fatigue-based loading protocol, after two cycles at 2.0% strain, more than 26 additional cycles at 1.5% strain were attained. The hysteresis curves for all six T-BRBs remained stable throughout the tests and the cumulative inelastic deformation exceeded two times the value required by the standard.
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Development of Timber Buckling Restrained Braces for Mass Timber Braced Frames

https://research.thinkwood.com/en/permalink/catalogue2544
Year of Publication
2019
Topic
Seismic
Design and Systems
Application
Frames
Author
Murphy, Colton
Pantelides, Chris
Blomgren, Hans-Erik
Rammer, Douglas
Organization
Forest Products Laboratory
Year of Publication
2019
Format
Conference Paper
Application
Frames
Topic
Seismic
Design and Systems
Keywords
Brace
Buckling
Damping
Fuse
Seismic
Structure
Timber
Conference
International Network on Timber Engineering Research
Research Status
Complete
Summary
Buckling Restrained Brace Frames (BRBF) are a proven and reliable method to provide an efficient lateral force resisting system for new and existing structures in earthquake prone regions. The fuse-type elements in this system facilitate stable energy dissipation at large load deformation levels. Currently, the new trend towards mass timber vertical structures creates a need for a lightweight compatible lateral force resisting system. A Buckling Restrained Brace (BRB) component is possible to construct and feasible to implement when combining a steel core with a mass timber casing herein named the Timber-Buckling Restrained Brace (T-BRB). T-BRBs when combined with mass timber beam and column elements can create a system that will have advantages over the current steel framed BRBF system when considering recyclability, sustainability, framing compatibility, and performance. This paper presents findings on small scale testing of candidate engineered wood products for the T-BRB casing and testing of six full scale 12 ft long 60 kip braces according to code prescribed loading protocols and acceptance criteria.
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Direct Displacement-based Seismic Design of Glulam Frames with Buckling Restrained Braces

https://research.thinkwood.com/en/permalink/catalogue3265
Year of Publication
2022
Topic
Seismic
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Author
Dong, Wenchen
Li, Minghao
Sullivan, Timothy
MacRae, Gregory
Lee, Chin-Long
Chang, Theodore
Organization
University of Canterbury
University College London
Publisher
Taylor&Francis Online
Year of Publication
2022
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Frames
Topic
Seismic
Keywords
Glulam Frame
Buckling Restrained Braces
Direct Displacement-Based Design
BRB-Timber Connections
Nonlinear Time-history Analyses
Research Status
Complete
Series
Journal of Earthquake Engineering
Summary
This paper presents a direct displacement-based design (DDBD) approach for the buckling restrained braces (BRBs) braced glue-laminated timber (glulam) frame (BRBGF) structures. First, the critical design parameters of the DDBD approach were derived for BRBGFs. Then, using experimentally verified numerical models, pushover analyses and nonlinear time-history analyses (NLTHAs) were conducted on a series of one-storey BRBGFs to calibrate the stiffness adjustment factor for BRB-timber connections and the spectral displacement reduction factor . Finally, the DDBD approach was verified as a prospective approach for the seismic design of multi-storey BRBGF buildings by NLTHAs of the case study buildings.
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Direct Displacement-Based Seismic Design of Timber Structures with Dowel-Type Fastener Connections

https://research.thinkwood.com/en/permalink/catalogue1899
Year of Publication
2012
Topic
Seismic
Connections
Application
Frames
Walls
Wood Building Systems
Author
Loss, Cristiano
Piazza, Maurizio
Zonta, Daniele
Publisher
Sociedade Portuguesa de Engenharia Sismica (SPES)
Year of Publication
2012
Format
Conference Paper
Application
Frames
Walls
Wood Building Systems
Topic
Seismic
Connections
Keywords
Direct Displacement-Based Design
Equivalent Viscous Damping
Dowel Type Fastener
Conference
15WCEE
Research Status
Complete
Notes
September 24-28, 2012, Lisbon, Portugal
Summary
The applicability of the Direct Displacement-Based Design (DBD) procedure is strictly related to a priori evaluation of the design displacement and the matching Equivalent Viscous Damping (EVD) of the structure. In this paper we propose analytical models of these design parameters, at the ultimate limit state, for wooden structures built with engineered joints. Experimental results show that the plastic resources and dissipative capabilities of timber structures under earthquake conditions are ensured by the connections between the members. Therefore, the formulation of the design DBD parameters is based on the mechanical model of the single connector and assumes the inelastic deformation of the structure to be concentrated at the joints. The expected non-linear response of the connections can be either ductile or brittle. However, through an appropriate choice of the geometry and strength characteristics of the materials, in the design process we can control the expected ductile behavior of joints.
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Displacement-Based Seismic Design of Timber Structures

https://research.thinkwood.com/en/permalink/catalogue1891
Year of Publication
2011
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
Other Materials
Application
Wood Building Systems
Walls
Floors
Beams
Columns
Frames
Author
Loss, Cristiano
Publisher
University of Trento
Year of Publication
2011
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
LVL (Laminated Veneer Lumber)
Other Materials
Application
Wood Building Systems
Walls
Floors
Beams
Columns
Frames
Topic
Design and Systems
Seismic
Keywords
Direct Displacement-Based Design
Direct-DBD
Full-Scale
Single Family Houses
Multi-Storey
Connections
Research Status
Complete
Notes
Doctoral Thesis (PhD)
Summary
The research is aimed at developing seismic methods for the design and evaluation of the seismic vulnerability of wooden structures, using a displacement-based approach. After a brief introduction on the seismic behaviour of timber structures, the general Direct Displacement-Based Design (Direct-DBD) procedure and the state-of-the-art are presented, with clear reference to the application of the Direct-DBD method to wooden buildings. The strength of the Direct-DBD method is its ability to design structures in a manner consistent with the level of damage expected, by directly relating the response and the expected performance of the structure. The research begins with a description of the procedural aspects of the Direct-DBD method and the parameters required for its application. The research presented focuses on the formulation of a displacement-based seismic design procedure, applicable to one-storey wooden structures made with a portal system. This typology is very common in Europe and particularly in Italy. A series of analytical expressions have been developed to calculate design parameters. The required analytical Direct-DBD parameters are implemented based on the mechanical behaviour of the connections, made with metal dowel-type fasteners. The calibration and subsequent validation of design parameters use a Monte Carlo numerical simulation and outcomes obtained by tests in full-scale. After the description of the Displacement-Based method for one-storey wooden structures, a series of guidelines to extend the Direct-DBD methodology to other types and categories of timber systems are proposed. The thesis presents the case of a multi-storey wood frame construction, which is a simple extension of the glulam portal frame system. Part of this work has been done within the RELUIS Project, (REte dei Laboratori Universitari di Ingegneria Sismica), Research Line IV, which in the years between 2005 and 2008 involved several Italian universities and Italian institutes of research in the development of new seismic design methods. The Project produced the first draft of model code for the seismic design of structures based on displacement (Direct-DBD). This thesis is the background to the section of the model code developed for timber structures.
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Dynamic Analysis and Comparison of High-Rise Building Frames Made of Mass-Timber and Traditional Materials Using Finite Element Analysis

https://research.thinkwood.com/en/permalink/catalogue2284
Year of Publication
2019
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Frames
Author
Kalathas, Paris
Publisher
Oregon State University
Year of Publication
2019
Format
Thesis
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Frames
Topic
Seismic
Keywords
Finite Element Analysis
Steel
Concrete
Vibration
Damping
Research Status
Complete
Summary
The increased demand for building materials that are friendly to the environment, along with the latest advances in wood science and technology, which exploit the fiber orientation of wood, resulted in composite wood materials known as mass-timber products. To understand the effects the wood fiber orientation has on the dynamic behavior of buildings and on vibration comfort, we examine twenty four high-rise building frames made from four different structural materials: conventional wood (Douglas-Fir), glued laminated timber (GluLam), cross laminated timber (CLT), steel and concrete. Utilizing the well-established Finite Elements Analysis (FEA), we study the building frames using a modal, a modal dynamics, an impulse response and an earthquake response analyses. These experiments revealed information about the frames such as natural frequencies (modes), resonance displacement, damping ratio, load propagation and dynamic response due to earthquake excitation. The results show that mass timber products, GluLam and CLT, when combined together demonstrate exceptional dynamic behavior, resulting in higher damping coefficients and reduced floor displacements compared to the other materials. However, they exhibited vibrations at a high frequency range, a behavior that needs further investigation in order to evaluate how it affects the integrity and longevity of the building frames.
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73 records – page 2 of 8.