twenty one transfer load subjected to tension or compression - - PowerPoint PPT Presentation

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ARCHITECTURAL STRUCTURES: FORM, BEHAVIOR, AND DESIGN

ARCH 331

• DR. ANNE NICHOLS

SPRING 2018

Steel Bolts & Welding 1 Lecture 21 Architectural Structures ARCH 331

lecture

nrmc.org

twenty one

steel construction: bolts, welds & light gages

Steel Bolts & Welding 2 Lecture 21 Foundations Structures ARCH 331 F2008abn

Connections

• needed to:

– support beams by columns – connect truss members – splice beams or columns

• transfer load
• subjected to

– tension or compression – shear – bending

F2008abn Steel Bolts & Welding 3 Lecture 21 Foundations Structures ARCH 331

Bolts

• bolted steel connections

(AISC - Steel Structures of the Everyday) http://courses.civil.ualberta.ca F2008abn Steel Bolts & Welding 4 Lecture 21 Foundations Structures ARCH 331

Welds

• welded steel connections

http://courses.civil.ualberta.ca

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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

Steel Bolts & Welding 5 Lecture 18 Foundations Structures ARCH 331 Steel Bolts & Welding 6 Lecture 21 Foundations Structures ARCH 331 F2008abn

Bolted Connection Design

• considerations

– bearing stress

• yielding

– shear stress

• single & double

– member

• rupture

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Bolts

• rarely fail in bearing
• holes considered 1/8” larger
• shear & tension

– single shear or tension – double shear

Steel Bolts & Welding 7 Lecture 18 Foundations Structures ARCH 331

75 0.

v 



b n n

A F R 

b n n

A F R 2 

n v u

R R    

n a

R R

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Bolts

Steel Bolts & Welding 8 Lecture 18 Foundations Structures ARCH 331 http://www.fastenal.com

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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”)

Steel Bolts & Welding 9 Lecture 18 Foundations Structures ARCH 331

75 0.  

u u c n

dtF . tF L . R 4 2 2 1  

n u

R R  

u u c n

dtF . tF L . R 3 5 1  

u u c n

dtF . tF L . R 2 1  

 

n a

R R

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Bolts

Steel Bolts & Welding 10 Lecture 18 Foundations Structures ARCH 331 Steel Bolts & Welding 11 Lecture 21 Foundations Structures ARCH 331 F2008abn

Welded Connection Design

• considerations

– shear stress – yielding – rupture

Steel Bolts & Welding 12 Lecture 21 Foundations Structures ARCH 331 F2008abn

Welded Connection Design

• weld terms

– butt weld – fillet weld – plug weld – throat

• field welding
• shop welding

(AISC - Steel Structures of the Everyday)

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Steel Bolts & Welding 13 Lecture 21 Foundations Structures ARCH 331 F2008abn

Welded Connection Design

• weld process

– melting of material – melted filler - electrode – shielding gas / flux – potential defects

• weld materials

– E60XX – E70XX FEXX = 70 ksi

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Welded Connection Design

• 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)

Steel Bolts & Welding 14 Lecture 18 Foundations Structures ARCH 331 Su2011abn

Welded Connection Design

• minimum

– table

• maximum

– material thickness ( to ¼”) – 1/16” less

• min. length

– 4 x size min. – ≥ 1 ½”

Steel Bolts & Welding 15 Lecture 18 Foundations Structures ARCH 331 Su2011abn

Welded Connection Design

• shear

– table for S

Steel Bolts & Welding 16 Lecture 18 Foundations Structures ARCH 331

area

 

n a

R R

n u

R R  

75 0.  

Sl Tl F . R

EXX n

  6

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Framed Beam Connections

• angles

– bolted – welded

Steel Bolts & Welding 18 Lecture 21 Foundations Structures ARCH 331 F2008abn

Framed Beam Connections

• terms

– coping

(AISC - Steel Structures of the Everyday) Su2011abn

Framed Beam Connections

• tables for standard

bolt sizes & spacings

• # bolts
• bolt diameter, angle

leg thickness

• bearing on

beam web

Steel Bolts & Welding 19 Lecture 18 Foundations Structures ARCH 331 Steel Bolts & Welding 20 Lecture 21 Foundations Structures ARCH 331 F2008abn

Framed Beam Connections

• welded example (shear)

(AISC - Steel Structures of the Everyday)

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Steel Bolts & Welding 21 Lecture 21 Foundations Structures ARCH 331 F2008abn

Framed Beam Connections

• welded moment example

(AISC - Steel Structures of the Everyday)

Steel Bolts & Welding 22 Lecture 21 Foundations Structures ARCH 331 F2008abn

Framed Beam Connections

• welded/bolted moment example

(AISC - Steel Structures of the Everyday)

Steel Bolts & Welding 23 Lecture 21 Foundations Structures ARCH 331 F2008abn

Framed Beam Connections

• welded/bolted moment example

(AISC - Steel Structures of the Everyday)

Steel Bolts & Welding 24 Lecture 21 Foundations Structures ARCH 331 F2008abn

Beam Connections

• LRFD provisions

– shear yielding – shear rupture – block shear rupture – tension yielding – tension rupture – local web buckling – lateral torsional buckling

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Beam Connections

– where Ubs is 1 for uniform tensile stress

Steel Bolts & Welding 25 Lecture 18 Foundations Structures ARCH 331

75 0.  

block shear rupture tension rupture

nt u bs gv y nt u bs nv u n

A F U A F . A F U A F . R     6 6

Steel Bolts & Welding 26 Lecture 21 Foundations Structures ARCH 331 F2008abn

Other Connections

• seated beam
• continuous

– beam to column – beam to beam

F2008abn Steel Bolts & Welding 27 Lecture 21 Foundations Structures ARCH 331

Other Connections

• splices

The Royal Ontario Museum Toronto . Canada Daniel Libeskind (AISC - Steel Structures of the Everyday) http://courses.civil.ualberta.ca Steel Bolts & Welding 28 Lecture 21 Foundations Structures ARCH 331 F2008abn

Other Connections

• rigid frame knees
• gussets & joints

(AISC - Steel Structures of the Everyday)

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Other Connections

• base plates

– anchor bolts – bearing on steel – bending of plate

http://courses.civil.ualberta.ca