Development of cold-formed steel moment-resisting connections with bolting friction-slip mechanism for seismic applications

Marzie Farnaz Shahini, Alireza Bagheri Sabbagh (Corresponding Author), Paul Cameron Davidson, Rasoul Mirghaderi

Research output: Contribution to journalArticle

Abstract

This paper presents an investigation into a friction-slip mechanism in bolted joints in cold-formed steel (CFS) moment-resisting connections suitable for seismic areas. The aim is to achieve higher ductility and energy dissipation capacity through an appropriately designed bolted connection, enabling activation of bolt slip, acting as a fuse mechanism, postponing the initiation of non-ductile local buckling in the CFS beams. By means of validated finite element analysis (FEA), both monotonic and cyclic performance of CFS connections comprising two types of square (SB) and circular (CB) bolt group arrangements, with four types of beam sections, are studied comparatively without and with slip at various levels. It is shown that the connections with slip provide higher energy dissipation capacity by up to 75% compared with that of the connections without slip. A design approach to predict an appropriate level for the connection slip moments to be initiated before the beam buckling moment is introduced using the direct strength method (DSM). On comparing the bolt forces obtained for the SB and CB groups, the CB connections produce a more uniform bolt-group force distribution which is closer to the idealised method; while the SB connection encounter a significant delay of up to 30% in activation of bolt group slip which could lead to unfavourable beam local buckling. Furthermore, to avoid an unfavourable hardening effect due to the bolts bearing action, slotted holes are used with a recommended length obtained for the cyclic movements of the bolts in the range of the designed connections. The instantaneous centre of rotation results show that the connections with slip have less deviation from the idealised centre of rotation than the connections without slip.
Original languageEnglish
Pages (from-to)217-231
Number of pages15
JournalThin-walled Structures
Volume141
Early online date22 Apr 2019
DOIs
Publication statusPublished - Aug 2019

Fingerprint

Bolts
Friction
Steel
Buckling
Energy dissipation
Bearings (structural)
Chemical activation
Bolted joints
Electric fuses
Ductility
Hardening
Finite element method

Keywords

  • cold-formed steel
  • friction –slip mechanism
  • seismic energy dissipation
  • moment-resisting bolted connections
  • bolt-group force distribution
  • Cold-formed steel
  • Moment-resisting bolted connections
  • Bolt-group force distribution
  • Seismic energy dissipation
  • Friction –slip mechanism

Cite this

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title = "Development of cold-formed steel moment-resisting connections with bolting friction-slip mechanism for seismic applications",
abstract = "This paper presents an investigation into a friction-slip mechanism in bolted joints in cold-formed steel (CFS) moment-resisting connections suitable for seismic areas. The aim is to achieve higher ductility and energy dissipation capacity through an appropriately designed bolted connection, enabling activation of bolt slip, acting as a fuse mechanism, postponing the initiation of non-ductile local buckling in the CFS beams. By means of validated finite element analysis (FEA), both monotonic and cyclic performance of CFS connections comprising two types of square (SB) and circular (CB) bolt group arrangements, with four types of beam sections, are studied comparatively without and with slip at various levels. It is shown that the connections with slip provide higher energy dissipation capacity by up to 75{\%} compared with that of the connections without slip. A design approach to predict an appropriate level for the connection slip moments to be initiated before the beam buckling moment is introduced using the direct strength method (DSM). On comparing the bolt forces obtained for the SB and CB groups, the CB connections produce a more uniform bolt-group force distribution which is closer to the idealised method; while the SB connection encounter a significant delay of up to 30{\%} in activation of bolt group slip which could lead to unfavourable beam local buckling. Furthermore, to avoid an unfavourable hardening effect due to the bolts bearing action, slotted holes are used with a recommended length obtained for the cyclic movements of the bolts in the range of the designed connections. The instantaneous centre of rotation results show that the connections with slip have less deviation from the idealised centre of rotation than the connections without slip.",
keywords = "cold-formed steel, friction –slip mechanism, seismic energy dissipation, moment-resisting bolted connections, bolt-group force distribution, Cold-formed steel, Moment-resisting bolted connections, Bolt-group force distribution, Seismic energy dissipation, Friction –slip mechanism",
author = "Shahini, {Marzie Farnaz} and {Bagheri Sabbagh}, Alireza and Davidson, {Paul Cameron} and Rasoul Mirghaderi",
year = "2019",
month = "8",
doi = "10.1016/j.tws.2019.04.011",
language = "English",
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pages = "217--231",
journal = "Thin-walled Structures",
issn = "0263-8231",
publisher = "Elsevier Limited",

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T1 - Development of cold-formed steel moment-resisting connections with bolting friction-slip mechanism for seismic applications

AU - Shahini, Marzie Farnaz

AU - Bagheri Sabbagh, Alireza

AU - Davidson, Paul Cameron

AU - Mirghaderi, Rasoul

PY - 2019/8

Y1 - 2019/8

N2 - This paper presents an investigation into a friction-slip mechanism in bolted joints in cold-formed steel (CFS) moment-resisting connections suitable for seismic areas. The aim is to achieve higher ductility and energy dissipation capacity through an appropriately designed bolted connection, enabling activation of bolt slip, acting as a fuse mechanism, postponing the initiation of non-ductile local buckling in the CFS beams. By means of validated finite element analysis (FEA), both monotonic and cyclic performance of CFS connections comprising two types of square (SB) and circular (CB) bolt group arrangements, with four types of beam sections, are studied comparatively without and with slip at various levels. It is shown that the connections with slip provide higher energy dissipation capacity by up to 75% compared with that of the connections without slip. A design approach to predict an appropriate level for the connection slip moments to be initiated before the beam buckling moment is introduced using the direct strength method (DSM). On comparing the bolt forces obtained for the SB and CB groups, the CB connections produce a more uniform bolt-group force distribution which is closer to the idealised method; while the SB connection encounter a significant delay of up to 30% in activation of bolt group slip which could lead to unfavourable beam local buckling. Furthermore, to avoid an unfavourable hardening effect due to the bolts bearing action, slotted holes are used with a recommended length obtained for the cyclic movements of the bolts in the range of the designed connections. The instantaneous centre of rotation results show that the connections with slip have less deviation from the idealised centre of rotation than the connections without slip.

AB - This paper presents an investigation into a friction-slip mechanism in bolted joints in cold-formed steel (CFS) moment-resisting connections suitable for seismic areas. The aim is to achieve higher ductility and energy dissipation capacity through an appropriately designed bolted connection, enabling activation of bolt slip, acting as a fuse mechanism, postponing the initiation of non-ductile local buckling in the CFS beams. By means of validated finite element analysis (FEA), both monotonic and cyclic performance of CFS connections comprising two types of square (SB) and circular (CB) bolt group arrangements, with four types of beam sections, are studied comparatively without and with slip at various levels. It is shown that the connections with slip provide higher energy dissipation capacity by up to 75% compared with that of the connections without slip. A design approach to predict an appropriate level for the connection slip moments to be initiated before the beam buckling moment is introduced using the direct strength method (DSM). On comparing the bolt forces obtained for the SB and CB groups, the CB connections produce a more uniform bolt-group force distribution which is closer to the idealised method; while the SB connection encounter a significant delay of up to 30% in activation of bolt group slip which could lead to unfavourable beam local buckling. Furthermore, to avoid an unfavourable hardening effect due to the bolts bearing action, slotted holes are used with a recommended length obtained for the cyclic movements of the bolts in the range of the designed connections. The instantaneous centre of rotation results show that the connections with slip have less deviation from the idealised centre of rotation than the connections without slip.

KW - cold-formed steel

KW - friction –slip mechanism

KW - seismic energy dissipation

KW - moment-resisting bolted connections

KW - bolt-group force distribution

KW - Cold-formed steel

KW - Moment-resisting bolted connections

KW - Bolt-group force distribution

KW - Seismic energy dissipation

KW - Friction –slip mechanism

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U2 - 10.1016/j.tws.2019.04.011

DO - 10.1016/j.tws.2019.04.011

M3 - Article

VL - 141

SP - 217

EP - 231

JO - Thin-walled Structures

JF - Thin-walled Structures

SN - 0263-8231

ER -