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SS019abnSteel Bolts & Welding 1

Lecture 21

Architectural Structures

ARCH 331

ARCHITECTURAL STRUCTURES:

FORM, BEHAVIOR, AND DESIGN

ARCH 331

DR. ANNE NICHOLS

SPRING 2019

lecture

twenty one

steel construction:

bolted & welded connectionsnrmc.org


Lecture 21


ARCH 331

Connections

• needed to:

– support beams by columns

– connect truss members

– splice beams or columns

• transfer load

• subjected to

– tension or compression

– shear

– bending


Lecture 21


ARCH 331

Bolts

• bolted steel connections

(AISC - Steel Structures of the Everyday)

http://courses.civil.ualberta.ca


Lecture 21


ARCH 331

Welds

• welded steel connections



Lecture 21


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Bolts

• types

– materials

• high strength

• A307, A325, A490

– location of threads

• included - N

• excluded - X

– bearing or friction (SC)

• always tightened


Lecture 21


ARCH 331

Bolted Connection Design

• considerations

– bearing stress

• yielding

– shear stress

• single & double

– member

• rupture


Lecture 21


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Bolts

• rarely fail in bearing

• holes considered 1/8” larger

• shear & tension

– single shear or tension

– double shear

7 5.0v

bnn AFR

bnn AFR 2

nvu RR

na

RR

SS019abn

Bolts

Steel Bolts & Welding 8

Lecture 21


ARCH 331

http://www.fastenal.com


Lecture 21


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Bolts

• bearing

– deformation is concern

– deformation isn’t concern

– long slotted holes

Lc – clear length to edge or next hole (ex. 1¼”, 3”)

7 5.0

uucn d t F.t FL.R 4221

nu RR



n

a

RR

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Bolts


ARCH 331


Lecture 121


Lecture 21


ARCH 331

Welded Connection Design

• considerations

– shear stress

– yielding

– rupture


Lecture 21


ARCH 331


• weld terms

– butt weld

– fillet weld

– plug weld

– throat

• field welding

• shop welding



Lecture 21


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• weld process

– melting of material

– melted filler - electrode

– shielding gas / flux

– potential defects

• weld materials

– E60XX

– E70XX

FEXX = 70 ksi


Lecture 21


ARCH 331


• shear failure assumed

• throat

– T = 0.707 x weld size

• area

– A = T x length of weld

• weld metal generally stronger than base metal (ex. Fy = 50 ksi)


Lecture 21


ARCH 331


• minimum

– table

• maximum

– material thickness ( to ¼”)

– 1/16” less

• min. length

– 4 x size min.

– ≥ 1 ½”

16316

58

316

78

5

SS019abn

• shear

– table for S


Lecture 21


ARCH 331


area

n

a

RR

nu RR 7 5.0

S lT lF.R E X Xn 60


Lecture 21


ARCH 331

Framed Beam Connections

• angles

– bolted

– welded


Lecture 21


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• terms

– coping



Lecture 21


ARCH 331


• tables for standard bolt sizes & spacings

• # bolts

• bolt diameter,

angle leg thickness

• bearing on

beam web


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• welded example (shear)



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• welded moment example



Lecture 21


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• welded/bolted moment example



Lecture 21


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Beam Connections

• LRFD provisions

– shear yielding

– shear rupture

– block shear rupture

– tension yielding

– tension rupture

– local web buckling

– lateral torsional buckling


Lecture 21


ARCH 331

– where Ubs is 1 for uniform tensile stress

7 5.0

block shear rupture tension rupture

n tub sg vyn tub sn vun AFUAF.AFUAF.R 6060

Beam Connections


Lecture 21


ARCH 331

Other Connections

• seated beam

• continuous

– beam to column

– beam to beam


Lecture 21


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Other Connections

• splices

The Royal Ontario Museum Toronto . CanadaDaniel Libeskind




Lecture 21


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Other Connections

• rigid frame knees

• gussets & joints



Lecture 21


ARCH 331

Other Connections

• base plates

– anchor bolts

– bearing on steel

– bending of platehttp://courses.civil.ualberta.ca

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