twenty one

(1)

A

RCHITECTURAL

S

TRUCTURES

:

F

ORM,

B

EHAVIOR, AND

D

ESIGN

ARCH 331

HÜDAVERDİ TOZAN

S

PRING 2013

lecture

twenty one

steel construction:

(2)

S2013abn Steel Bolts & Welding 2

Lecture 21

Architectural Structures ARCH 331

Connections

• needed to:

– support beams by columns

– connect truss members

– splice beams or columns

• transfer load

• subjected to

– tension or compression

– shear

(3)

Bolts

• bolted steel connections

(4)

Lecture 21

Welds

• welded steel connections

(5)

Bolts

• types

– materials

• high strength

• A307, A325, A490

– location of threads

• included - N

• excluded - X

– friction or bearing (SC)

(6)

Lecture 21

Bolted Connection Design

• considerations

– bearing stress

• yielding

– shear stress

• single & double

– member

(7)

Bolts

• rarely fail in bearing

• holes considered 1/8” larger

• shear & tension

– single shear or tension

– double shear

7 5

.

0 

v



b

n

F

A

R



b

n

F

A

R



2 n

v

u

R









n

a

R

(8)

S2013abn

Bolts

Steel Bolts & Welding 8 Lecture 21

(9)

Bolts

• bearing

– deformation is concern

– deformation isn’t concern

– long slotted holes

L

_c

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

7 5

.

0 



u

c

n

.

L

t F

.

d t F

R



1

2 

2

4 n

u

R





u

c

n

.

L

t F

.

d t F

R



1

5 

3

0 u

u

c

n

.

L

t F

.

d t F

R



1

0 

2

0 



n

a

R

(10)

S2013abn

Bolts

Architectural Structures ARCH 331 Steel Bolts & Welding 10

(11)

Welded Connection Design

• considerations

– shear stress

– yielding

(12)

Lecture 21

Welded Connection Design

• weld terms

– butt weld

– fillet weld

– plug weld

– throat

• field welding

• shop welding

(13)

Welded Connection Design

• weld process

– melting of material

– melted filler - electrode

– shielding gas / flux

– potential defects

• weld materials

– E60XX

– E70XX

(14)

Lecture 21

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

(15)

Welded Connection Design

• minimum

– table

• maximum

– material thickness ( to ¼”)

– 1/16” less

• min. length

– 4 x size min.

– ≥ 1 ½”

16 3 16 5 8 3 16 7 8 5

(16)

S2013abn

• shear

– table for



S

Steel Bolts & Welding 16 Lecture 21

Welded Connection Design

area





n

a

R

n

u

R





7 5

.

0 



S l

T l

F

.

R

_n



0

6 _{E X X}



(17)

Framed Beam Connections

• angles

– bolted

– welded

(18)

Lecture 21

Framed Beam Connections

• terms

– coping

(19)

Framed Beam Connections

• tables for standard

bolt sizes & spacings

• # bolts

• bolt diameter, angle

leg thickness

• bearing on

(20)

Lecture 21

Framed Beam Connections

• welded example (shear)

(21)

Framed Beam Connections

• welded moment example

(22)

Lecture 21

Framed Beam Connections

• welded/bolted moment example

(23)

Framed Beam Connections

• welded/bolted moment example

(24)

Lecture 21 Architectural Structures ARCH 331

Beam Connections

• LRFD provisions

– shear yielding

– shear rupture

– block shear rupture

– tension yielding

– tension rupture

– local web buckling

(25)

– where U

_bs

is 1 for uniform tensile stress

7 5

.

0 



block shear rupture

_{tension rupture}

n t

u

b s

g v

y

n t

u

b s

n v

u

n

.

F

A

U

F

A

.

F

A

U

F

A

R



0

6 



0

6 

Beam Connections

(26)

Lecture 21 Architectural Structures ARCH 331

Other Connections

• seated beam

• continuous

– beam to column

– beam to beam

(27)

Other Connections

• splices

The Royal Ontario Museum Toronto . Canada Daniel Libeskind

(AISC - Steel Structures of the Everyday)

(28)

Lecture 21

Other Connections

• rigid frame knees

• gussets & joints

(29)

Other Connections

• base plates

– anchor bolts

– bearing on steel