CE591shearstuds_F13

8/13/2019 CE591shearstuds_F13

1/54

CE591 Lecture 10: Composite Beams;

Shear Connectors; Metal Decking

Metal Deck, Shear Connectors

Shear Studs and Metal Deck

Capacity, Qn

Limits on Spacing, etc.

Calculation of Positive Design Flexural

Strength


2/54


3/54

Metal Deck


4/54

Thickness16 to 22 gage (~0.064 to ~0.034)


5/54


6/54

Puddle welds


7/54Wang Hall, Purdue University


8/54

AISC I3.2csteel deck shall be anchored to all

supporting members at a spacing not to exceed 18 (can

be from combination of shear studs and puddle welds)

Deck

manufacturersmay specify

placement


9/54

Button-punching deck

http://www.vercodeck.com/index.php?option=com_content&view=article&id=267&Itemid=875


10/54


11/54


12/54

Shear Connectors

From Geschwindner, Unified Design of Steel Structures, 2nded.


13/54

Shear studs (steel headed stud

anchor) and ferrules


14/54

Typically

3/4 or 7/8diameter

(3/4 required with

metal deck)

Height ~ 2 8


15/54

Placing shear studs


16/54


17/54


18/54


19/54

Welded wire fabric (WWF)


20/54

Welded wire fabric

W1.4 x 1.4

6 x 6

Spacing (inches)

diameter of

wire, 10 gage,

d ~ 1/8


21/54


22/54

May add reinforcement across girders

AISC C-I3.2where longitudinal cracking detrimental

to serviceability is likely to occur, slab should be

reinforced transverse to the supporting steel section ...

cr AA 002.0


23/54


24/54

Shear Studs and Metal Deck

Ribs parallel to axis of beam Ribs perpendicular toaxis of beam


25/54

Composite Floor System Design Techniques, 2013 NASCC

Will Jacobs, Sam Easterling

media.aisc.org/NASCC2013/N14a.mp4
http://media.aisc.org/NASCC2013/N14a.mp4http://media.aisc.org/NASCC2013/N14a.mp4


26/54

Ideallyrigid, no slip

Realitystud can

deform, concrete

crushes, get some slip

Q

d


27/54

Strength of stud connectors for

composite beams

usapgccsan FARREfAQ '5.0

75.0

0.1

p

g

R

RNo metal deck?

Eq. (I8-1)


28/54

(Easterling, 2007)


29/54


30/54

wr

Hs hr

Hs=length of stud after welding

Hs

hr

+ 1-1/2

AISC I3.2c and I8.2

Hs 4ds


31/54

From AISC-LRFD 3rdedition


32/54

AISC Predicted Strength, QN

Exp

erimentalStu

dStrength,Q

e


33/54


34/54

(Easterling, 2007)


35/54

(Easterling, 2007)


36/54


37/54

(Easterling, 2007)


38/54

5.1r

r

h

w*0.85 if thru deck and ; 1.0 if 5.1

r

r

h

w


39/54

Rp= 0.75


40/54

ine htmid 2 ine htmid 2

Rp= 0.75 Rp= 0.6

emid-ht= distance from edge of stud shank to steel deck

web, measured at mid-height of the deck rib, and in the

load bearing direction (i.e. direction of max moment for

simply supported beam


41/54


42/54

AISC

[16.1-98]


43/54

(Easterling, 2007)


44/54

(Easterling, 2007)


45/54





46/54

Limits

wr 2

Hs32 1-1/2

AISC I3.2cds (based on test results)


47/54

wr 2 For one stud,

+ 4dsfor eachadditional stud

When nominal

hr 1-1/2

(AISC I3.2c)

Deck rib permitted

to be split

longitudinally and

separated to form aconcrete haunch

AISC I8.2d


48/54

Limits, contd.

4 ds

2 ds (recommended)

6 ds (in general)

4 ds(for ribs perpendicular to beam)

8 tsand 36(in any direction)

5 minimum flange width for 2 rows of studs (for stud)8 minimum flange width for 3 rows of studs (for stud)

AISC I8.1


49/54

Limits, contd.

fs td 5.2Unless stud placed over web


50/54

Limits, contd.

AISC I8.2d

Lateral cover of 1

for shearconnectors,

except in ribs of

formed steel decks

1/2 reqd, ~1 typ.


51/54

Calculation of fMn

Ribs perpendicular toaxis of beam

AISC I3.2c

Concrete below top of

deck (in ribs) shall be

neglected for section

properties and

calculation of Ac

(strength, etc.)


52/54

Calculation of fMn

Ribs parallel to axis of beam

AISC I3.2c

Concrete below top of

deck (in ribs) is

permitted be included

for section properties

(Ix)

and SHALL be

included in calculationof Ac(strength)


53/54

Lateral bracing during construction

(concrete placement)

With puddle welds / studs / combination at

no more than 18 o.c.

Beams are fully laterally braced Girders are perhaps not braced by the

deck

Depends on girderfiller beam detail

Recommend using filler beam spacing as

unbraced length at construction stage


54/54




Documents

CE591shearstuds_F13