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