PROJECT : PAGE :

CLIENT : DESIGN BY :
JOB NO. : DATE : REVIEW BY :
Steel Corbel Design Based on AISC-ASD 9th, Appendix F

DESIGN CRITERIA
1. IN ORDER TO QUALIFY UNDER THIS DESIGN, THE TOP & BOT
FLANGES SHALL INPUT ZERO (APP. F7.1.b, page 5-102),
ALTHOUGH TOP FLANGE ALWAYS EXISTS.
2. FOR RECTANGLE GUSSET PLATE, INPUT
d0 EQUAL TO dL .
3. THE END FORCES, P, F & M, SHOULD INCLUDE
IMPACT FACTOR, IF THEY ARE FROM DYNAMIC
LOADS. (A4.2, page 5-29)

INPUT DATA & DESIGN SUMMARY

CORBEL DIMENSIONS bf = 1.25 in ( 32 mm )
tf = 1.25 in ( 32 mm )
tw = 1.25 in ( 32 mm ) THE CORBEL DESIGN IS ADEQUATE.
dL = 22 in ( 559 mm )
d0 = 12 in ( 305 mm ) LOADS (ASD) F= 16.0 kips ( 71.2 kN )
L= 3 ft ( 0.9 m ) P= 80.0 kips ( 355.8 kN )
STEEL YIELD STRESS Fy = 50 ksi ( 345 N / mm2 ) M= 30.0 ft-kips ( 133.4 kN-m )

ANALYSIS
DETERMINE ALLOWABLE FLEXURAL STRESS (APP. F7.4, pg 5-103)

  
 2 1.0  Fy
 F y 0.60 F y , for F b  F y / 3
3
F b   6 B F s  F w 
2 2

 B F 2s F 2w , for F b F y / 3

where Af = tf bf g = MIN[(dL - d0) / d0 , 0.268 L/d0, 6.0]
ATo = tf bf + d0 tw / 6 ITo = (tf bf3 + d0 tw3 / 6) / 12

I To 12000
r To 
ATo
F s 
h sL d o / A f

 1.0  0.0230 Ld 0 170000

hs F w 
 h wL / r To 
Af 2

L 1.75
hw  1.0  0.00385 B 
r To 1.0  0.25 

Length g ATo ITo rTo Hs Hw Fsg Fwg B Fbg

Corbel 3.029 0.80 4.06 1 0.36 1.31 1.03 33.20 16.07069 1.43 28.06

DETERMINE ALLOWABLE SHEAR STRESS (F4, pg 5-49)

where h = dL - 2 tf
0.4 F , for h / t 380 F
 y w y
Fv  C F
  45000 k v
 v y 0.4 F y , for h / t w380 F y  4.0
5.34
, for a / h1.0  , for C v 0.8
 F y h / t w 
2
 2.89   a / h 2
kv   Cv  
5.34  4.0  190 k v , for
, for a / h 1.0 h/t C v 0.8
  a / h 2 w Fy
0.5  
a h h / tw 380 / Fy Kv Cv Fbg
Corbel 3.0 19.50 16 54 6.51 4.40 20.00

DETERMINE ALLOWABLE COMPRESSIVE STRESS (APP. F7.3, pg 5-102)

where Kg = (effective length factor by an analysis)

 2  S = Kg l / rox
 1.0  S  F y
 2C c2 
 , for S C c
 5 3S 3
F a   3  8  8S 3 2 2E
 Cc Cc Cc 
 2 E= F
29000
y ksi
12 E , for S 
 Cc
 23S 2 Kg Cc Ix rox Fag
l A S
Corbel 3.0 2 107 236.25 18.13 3.61 19.94 28.31

CHECK EACH SECTION CAPACITIES

d0 dL tf bf tw Af
Corbel 12 22 1.25 1.25 1.25 1.5625
 (cont'd)

Section Fixed 1/3 L 2/3 L End

d (in) 22 19 15 12
I (in4) 1487.29 949.75 559.21 292.50
Aw (in2) 27.50 23.33 19.17 15.00
N (kips) 16.0 16.0 16.0 16.0
V (kips) 80.0 80.0 80.0 80.0
M (ft-k) 270 190 110 30
fa (ksi) 0.52 0.60 0.72 0.88
Fa (ksi) 28.31 28.31 28.31 28.31
fv (ksi) 2.91 3.43 4.17 5.33
Fv (ksi) 20.00 20.00 20.00 20.00
fb (ksi) 24.0 22.4 18.1 7.4
Fb (ksi) 28.06 28.06 28.06 28.06

fa < Fa [Satisfactory] fv < Fv [Satisfactory] fb < Fb [Satisfactory]

CHECK COMBINED FLEXURE AND AXIAL FORCE (APP. F7.4, pg 5-104)

 f a0 f f a0
  bl , for  0.15
 F a F b F a
1.3
  f a0 C m ' f bl 

   
 f a , f b   a  1  f a 0 
F 
F b
 
 L arg er of   f
 F 'e   , for a0
 0.15
   F a
  f a0 f 
   bl 
 f
 f 0.6 F y F F b
F  Feg' Cm' ( fa , fb )
a0 bl ag bg
Column 0.52 23.96 28.31 28.06 375.47 1.00 0.87 [Satisfactory]

Technical Reference:
1. AISC: "Manual of Steel construction 9th", American Institute of Steel Construction, 1990.
2. AISC: "Design Guide 25: Frame Design Using Web-Tapered Members, 2010.