Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Numerical investigation of braces and replaceable links for steel frames
Download
12626120.pdf
Date
2021-2-10
Author
Kazemzadeh Azad, Sina
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
314
views
761
downloads
Cite This
Concentrically braced frames (CBFs) and eccentrically braced frames (EBFs) are among popular lateral load resisting systems for steel structures. The present study investigates different aspects of these systems. The part devoted to EBFs begins with a comprehensive review of research where 22 future research needs are identified and presented. This is followed by an experimental study on the low-cycle fatigue behavior of links, which are the most important members of an EBF. Results of the experimental study are then combined with a comprehensive database of previous experiments available in the literature and synthesized to calibrate a cumulative damage law for estimating the exhausted as well as the remaining life of a link during an earthquake. A simple 8-step algorithm was outlined which utilizes the developed damage law for estimating the accumulation of damage as well as the instant of link fracture in nonlinear time history analysis under earthquake-induced loading histories. The algorithm can also contribute significantly to the decision-making process of the post-earthquake replacement of EBF links. In addition, in the EBF part of the thesis, a replaceable link detail with a mid-splice connection (referred to herein as the detachable replaceable link concept), recently developed at METU, is numerically investigated. After reviewing the previous experiments conducted on the concept, a comprehensive parametric study is carried out and a design equation is developed for estimating the axial force that the midsplice connection can experience due to large link deformations and end restraint effects. In order to further investigate the application of the proposed detail for larger (deeper) shear links than those previously tested, another set of sophisticated simulations is conducted. The analysis results further suggest the potential of the detachable concept for practical applications. For the CBF part of the thesis, first, the seismic design rules recommended by American and European provisions are thoroughly reviewed and compared. A series of CBF archetypes are then designed based on American and European provisions and subjected to a large set of earthquakes in order to investigate and compare their seismic performances. Results of more than 800 nonlinear time-history analyses reveal that the differences which exist between these provisions can lead to significant differences in the observed seismic performances. The most notable difference is the occurrence of soft-story behavior at the top stories of the CBF archetypes designed according to European provisions. Possible reasons for this phenomenon are investigated and recommendations are provided. In the last part of the thesis, the effect of rapid shortening of braces during earthquakes on the seismic behavior of CBFs is investigated. Axially loaded members might experience compressive forces above their static buckling capacity as a result of dynamic buckling under such rapid shortenings. A theoretical background on the topic is provided followed by a comprehensive parametric study considering several CBF configurations under a large set of earthquakes. Results of a total of 1600 nonlinear time-history analyses are utilized to demonstrate the frequency of occurrence and importance of this phenomenon particularly for the capacity design of columns, beams, and gusset plates of CBFs. The implications of these extra forces were discussed, and a simple formula was developed which can be used for the estimation of the ultimate brace force (considering the dynamic buckling effect) during the capacity design of CBF systems
Subject Keywords
Eccentrically braced frames
,
Concentrically braced frames
,
Replaceable links
,
Low-cycle fatigue
,
Dynamic buckling
URI
https://hdl.handle.net/11511/89594
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
An Experimental Study on Welded Overlap CoreSteel Encased Buckling-restrained Braces
Bozkurt, Mehmet Bakır; Topkaya, Cem (null; 2017-09-13)
Buckling restrained braced frames (BRBFs) can be used as a lateral load resisting system in seismic regions. A typical buckling restrained brace (BRB) is composed of a core segment, debonding material and a buckling restraining mechanism (BRM). The cross‐section of the core segment can be changed along the length to constrain yielding in a limited domain. Most of the BRBs utilize a rectangular core segment which is reduced in width throughout yielding length. The gradual reduction in the width of the core s...
Comparison of chevron and suspended-zipper braced steel frames
Ozcelik, Yigit; Sarıtaş, Afşin; Clayton, Patricia M. (2016-03-01)
Suspended-zipper braced frame is a modified configuration of chevron braced frame in which zipper columns are added between story beams and a hat truss is attached between top two stories in order to redistribute the unbalanced vertical forces emerging following the brace buckling to avoid the use of deep beams. In this study, three- and nine-story chevron and suspended-zipper braced frames are analyzed to compare their seismic performances. The beams, columns, braces and zipper columns are modeled using no...
Experimental and numerical studies on replaceable links for eccentrically braced frames
Özkılıç, Yasin Onuralp; Topkaya, Cem; Department of Civil Engineering (2020)
Eccentrically braced frames (EBFs) are extensively used as a steel lateral load resisting systems in high seismic regions since EBFs simulate ductility and high energy absorption capacity of moment resisting frames (MRFs) and high stiffness of concentrically braced frames (CBFs). High stiffness and high ductility of EBFs are obtained from diagonal braces and yielding of link element, respectively. This thesis reports findings of a three phase experimental and numerical research program on replaceable links ...
Comparative seismic behavior assessment of a new damper-equipped and conventional chevron-braced frames
Milani, Ali Salem; Dicleli, Murat (2023-02-01)
This paper presents the results of experimental studies performed on three 1/3-scale steel building frames for comparative assessment of the cyclic behavior of a Chevron frame equipped with a newly-developed damper, THDF (Torsional Hysteretic Damper for Frames) in relation to a Chevron special concentrically braced frame (SCBF) and an eccentrically braced frame with a vertical H-link. THDF is a damper with a displacement-dependent post-elastic stiffness, developed for Chevron frames. First, the SCBF was des...
Seismic response of a single story innovative steel frame system
Dicleli, Murat (2005-01-01)
The presented research studies the seismic response of a new braced steel frame type and a new design philosophy that will focus on minimizing damage to the essential structural members and ensuring satisfactory post-earthquake performance of steel buildings under service loads with minimal rehabilitation costs. The proposed frame type is composed of beams and columns with rigid connections, chevron braces and a conventional energy-dissipating member called the shear element connected between the braces and...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
S. Kazemzadeh Azad, “Numerical investigation of braces and replaceable links for steel frames,” Ph.D. - Doctoral Program, Middle East Technical University, 2021.