aisc-asd89
DESCRIPTION
exTRANSCRIPT
Flowchart for the design result check of steel member
Start
Determine class of cross section(compact, non-compact, slender)
Check design axial stress
Check design shear stress
D
A
A'
B'
Check combined stresses
C
D'
End
Check design bending stress
B
C'
Specify general requirementsto assure stability of the structure as a whole
B5.1
C1,2
Flowchart A-A', design axial stress
A
B7.
Check slenderness
A'
Determine design tensile stress (Ft )
Flowchart A1-A1', design tensile stress
Check design axial stress
A1
A2
A1'
A2'
A1
A1'
D1.
Is compression member?
No
Yes
A2
Determine Qs , Qa
Flowchart A2-A2', design compressive stress
Determine Cc
Determine Fa
A - B5.2c
(E2-1~2), (A - F7-2~3)
Determine design compressive stress (Fc)
AISC specification for allowable stressdesign of single-angle members - 4.
A2'
Determine S(Kl/roy,Kl/roz), Cc
A - F7.3E2.
A - B5.2a, b, c
Is single-angle member?
No
Yes
Is web-tapered?Yes
No
Is slender member?
Yes
No
Is singly symmetric shapes ?
No
Yes
Determine Faor Fa
AISC-LRFD86 E3. (A-E3-6)
Determine Fcr
Determine e
Determine Fe
(A - E3-5~7)
(A - E3-4)
(A - E3-2~3)
A2'
Is doubly symmetric shapes ?
No
YesAISC-LRFD86 E3. (A-E3-5)
AISC-LRFD86 E3. (A-E3-7)
F1. Strong Axis Bending of I-shaped Members and Channels
Flowchart B-B', design bending stress
Allowable stress (Fb)
F1.1 (F1-1)
Compact Sections (Fb)
F1.1 (F1-1)
Noncompact Sections (Fb)
F1.2 (F1-3~5)
Unbrace Length Greater than Lc (Fb)
F1.3 (F1-2, F1-6~8)
F2. Weak Axis Bending of I-shaped Members, Solid Bars and Rectangular Plates
Compact Sections (Fb)
F2.1 (F2-1)
Noncompact Sections (Fb)
F2.2 (F2-2~3)
F3. Bending of Box Members, Rectangular Tubes and Circular Tubes
Compact Sections (Fb)
F3.1 (F3-1~2)
Noncompact Sections (Fb)
F3.2 (F3-3)
a1
a2
a3
b1
b2
c1
c2
B'B1 B1'
Allowable flexural stress (Fb )
A - F7.4
B'
Is single-angle member ?
No
Yes
Is web-tapered ?Yes
No
B
G2.
YesIs Plate Girder ?
bw Fth /760/ > B'
No
Shape ?F1. Condition OK F3. Condition OK
F2. Condition OK
Web Local Buckling(WLB) Compact ?
B5.1
Flange Local Buckling(FLB) Compact ?
B5.1
Yes
No
No
Yes
b1
b2
b2
F.
Web Local Buckling(WLB) Compact ?
B5.1
Flange Local Buckling(FLB) Compact ?
B5.1
Yes
No
No
Yes
a2
Web Local Buckling(WLB) Compact ?
B5.1
Flange Local Buckling(FLB) Compact ?
B5.1
Yes
No
No
Yes
c2
c2
c1
b' c'
B’
Lateral Torsional Buckling(LTB) Satisfy ?
F1.1 (F1-2)No
Yes
a3
Yes
a1
a'
a2
Allowable bending stress (Fb’ FbRPGRe)≤
Flowchart B1-B1', bending stress of angle(AISC specification for allowable stress design
of single-angle members)
Determine Fob
5.3.1 (5-5)
B1
Determine Fob
5.3.2 (5-6)
Determine Fb by the limit state of local bucklingwhen the tip of angle leg is in compression
5.1.1
Determine Fb by the limit state oflateral-torsional buckling
5.1.3
Determine Fb by the limit state of yieldingwhen the tip of an angle leg is in tension
Determine Fb by the limit state of local bucklingwhen the tip of angle leg is in compression
5.1.1
5.1.2
Determine Fb
B1'
Is major-axis bending?No
Yes
Is equal-leg angle?
Is leg tip in tension?
Yes
No
No
Yes
C
Flowchart C-C', combined stresses
Check axial compression and bending
H1. (H1-3)
Check axial tension and bending
C'
D
Flowchart D-D', shear stress
Is tension member?Yes
No
Allowable shear stress with tension field action
G3.
YesIs Plate Girder ?
bw Fth /760/ > D'
F.
Check combined flexure and axial force
A - F7.6
C'Is web-tapered ?Yes
No
H2. (H2-1)
Check allowable shear stress (Fv)
F4. (F4-1~2)
D'
fa/Fa 0.15≤
Check axial compression and bending
H1. (H1-1~2)No
Yes
No