steeldesign plategirder fu new

7/25/2019 SteelDesign PlateGirder Fu New

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ENCE 710Design of SteelStructures

VI. Plate GirdersC. C. Fu, Ph.D., P.E.

Ci il and En iron!ental EngineeringDe"art!ent

#ni ersit$ of %ar$land


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IntroductionFollo&ing su'(ects are co ered)

%o!ent strength

Shear strengthInter!ediate trans erse sti*ener+earing sti*ener

eading)Cha"ters 11 of Sal!on - ohnson/ISC FD S"eci cation Cha"ters + 2Design

e3uire!ents4 and F 2Design of %e!'ers forFle5ure4 and G 2Design of %e!'ers for Shear4


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3

6$"ical Plate Girders


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4

/ISC

i!itingatios


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/ISC Design of %e!'ers forFle5ure

2a'out %a(or /5is4


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+ea! sPlateGirder

2for dou'l$ s$!!etric I sha"ed

Plate Girder) / dee"'ea!

8Slender9 &e' "ro'le!s)

1.:e' 'uc;ling


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Vertical +uc;ling2the co!"ression =ange4

2a4 ateral 'uc;ling

2'46orsional 'uc;ling

2c4 Vertical 'uc;ling


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/ISC %a5i!u! :e' h?t &Sti*ened girder 2for a/h 1.5)

h/t w = 11.7 E/Fy 2/ISC F1>.>4

Sti*ened girder 2for a/h @ 1.A4

h/t w 0.42E/F y 2/ISC F1>.B42S - 6a'le 11.>.14

#nsti*ened girder h/t w 260


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/ISC No!inal %o!ent

StrengthIf h/t w 5.70E/F y /ISC 6a'le +B.1 treated as rolled 'ea!sIf h/t w > 5.70E/F y

Case 1 Co!"ression =ange $ieldingMn = R pg F y S xc 2FA 14

Case < ateral 6orsional +uc;lingMn = R pg F cr S xc 2FA r 2FA B, A, 4

2for : +4

a & ratio of &e' area to co!"ression =ange area 2 104h c < 5 centroid to inside face of the co!"ression =ange

( ) y pr

pb y ybcr F

L L

L L F F C F

= 3.0

2

2

=

t

b

bcr

r

L

E C F

yt r F

E r L

7.0 =

170.53001200

1

+= yw

c

w

w pg F

E

t

h

a

a R

6/1(12 w fc

t abr +=


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/ISC No!inal %o!entStrength 2cont.4

Case > Co!"ression =ange local 'uc;lingMn = R pg F cr S xc 2FA 74

F cr a. # # p $ F cr = F y ". # p ! # # r $

2FA 4

c. # > # r $ 2FA H4

% c = 4/&h/t w ) and 0.'5 % c 0.76'Case B 6ension =ange $ielding 2S 5t S 5c 4

Mn = R pt F y S xt 2FA 104

( )

= pf rf

pf y ycr F F F

3.0

2

2

9.0

=

f

f

ccr

t

b

k F


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i!itStates inFle5ure

for "late girder&ith slender&e' 2/ISC FA4


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Co!"arison of 6+

2/ISC FA &ith /ISC F


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Classical Shear 6heor$2a""lied to "late girder &e'"anel4


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Inter!ediate Sti*ener

S"acing


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/ISC No!inal ShearStrengthIf h/t w 1.10 &% ( E/F y )

n = 0.6 * wF y sa!e as rolled 'ea! 2G> 14

If h/t w > 1.10 &% ( E/F y )

2G>


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/ISC No!inal ShearStrength 2cont.4

For 1.10 &% ( E/F y ) h/t w 1.'7 &% ( E/F y )

- ( = 1.10 &% ( E/F y ) / &h/t w ) 2G< B4

For h/t w > 1.'7 &% ( E/F y )

- ( = 1.51 % ( E/+&h/t w ) 2F y , 2G< A4

% ( = 5 5/&a/h) 2 if a/h ' and +260/&h/t w ), 25 other&ise

2S - Fig. 11. .>4


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Shear Ca"acit$ / aila'le

Figure 11.8.1 Shear ca"acit$ a aila'le, considering "ost 'uc;lingstrength.


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6ension Field /ction.

Figure 11.8.2 6ension eld action.


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+uc;ling of Plate Girder :e'

Figure 11.7.3+uc;ling of "late girder&e' resulting fro!shear aloneJ/ISC G4

M:n. t = w/&0.56/E/F y )


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E5a!"le Girder loading and su""ort fordesign


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E5a!"le

Factored !o!entand factored shearen elo"es for t&os"an continuous'ea! of illustrati ee5a!"le


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E5a!"le Design S;etch

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