The Omega Factors setup window ( Job Settings )
- Omega factors affect calculations that connection design makes when ' ASD13 ' is the " Connection design method ."
- The defaults settings on this window are the omega factors recommended by AISC and should not be changed except to meet local design codes, for example, outside of the United States.
- See to open Omega Factors .
Also see :
- Connection design method (set to ' ASD13 ' to open this window)
- Connection design (entries made here are applied during)
- Text entry widgets (making entries on this window)
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To open this window :
1 . On the " Design Settings " window, select ' ASD13 ' as the " Connection design method ."
2 . Press the " Omega Factors " button.
3 . The Omega Factors window opens.
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Tension yielding in gross section ( D2 (a) ): Per AISC, the default omega factor is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section D2.(a), page 16.1-26.
Tension fracture in net section ( D2 (b) ): Per AISC, the default omega factor is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section D2.(b), page 16.1-27.
Pin-connected members :
Tensile rupture on the net effective area ( D5 (a) ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section D5.(a), page 16.1-28.
Shear rupture on the net effective area ( D5 (b) ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section D5.(b), page 16.1-30.
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General provisions ( E1 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section E1, page 16.1-32.
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General provision ( F1 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section F1, page 16.1-46.
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General provisions ( G1 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section G1, page 16.1-64.
For webs of rolled I-shaped members ( G2 (a) ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section G2.(a), page 16.1-65.
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Double and singly symmetric members in flexure and compression :
Compression ( H1.1 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section H1.1, page 16.1-71.
Flexure ( H1.1 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section H1.1, page 16.1-71.
Double and singly symmetric members in flexure and torsion :
Flexure ( H1.2 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section H1.2, page 16.1-71.
Unsymmetric and other members subject to flexure and axial force :
Compression ( H2 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section H2, page 16.1-73.
Flexure ( H2 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section H2, page 16.1-73.
Torsion and combined torsion, flexure :
Shear, and/or axial force ( H3.1 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section H3.1, page 16.1-74.
Strength of non-HSS members under torsion and combined stress ( H3.3 ): Per AISC, the default omega factor is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Commentary H3.3, page 16.1-76.
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Encased composite columns :
Compressive strength ( I2.1b ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section I2.1b, page 16.1-79.
Tensile strength ( I2.1c ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section I2.1c, page 16.1-80.
Load transfer ( I2.1e (b) ): Per AISC, the default omega factor (Ω) is 2.31 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section I2.1e, page 16.1-81.
Filled composite columns :
Tensile strength ( I2.2c ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section I2.2c, page 16.1-82.
Load transfer ( I2.2e ): Per AISC, the default omega factor (Ω) is 2.31 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section I2.2e, page 16.1-82.
Flexural members :
Positive flexural strength ( I3.2a ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section I3.2a, page 16.1-83.
Negative flexural strength ( I3.2b ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section I3.2b, page 16.1-84.
Flexural strength of concrete-encased and filled members :
Limit state of yielding ( I3.3(a) and (b) ): Per AISC, the default omega factor is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section I3.3.(a) and (b), page 16.1-88.
Shear connectors ( I3.3 (c) ): Per AISC, the default omega factor (Ω) is 1.76 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section I3.3.(c), page 16.1-89.
Combined axial force and flexure :
Compressive strength ( I4 ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section I4, page 16.1-89.
Flexural strength ( I4 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section I4, page 16.1-89.
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Partial-joint-penetration groove welds ( Table J2.5 ) :
Tension on base metal: Per AISC, the default omega factor is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Table J2.5, page 16.1-99.
Tension on weld metal: Per AISC, the default omega factor is 1.88 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Table J2.5, page 16.1-99.
Compression on connections finished-to-bear, base metal: Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Table J2.5, page 16.1-99.
Compression on connections finished-to-bear, weld metal: Per AISC, the default omega factor (Ω) is 1.88 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Table J2.5, page 16.1-99.
Compression on connections not finished-to-bear, base metal: Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Table J2.5, page 16.1-99.
Compression on connections not finished-to-bear, weld metal: Per AISC, the default omega factor (Ω) is 1.88 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Table J2.5, page 16.1-99.
Shear on weld metal: Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Table J2.5, page 16.1-99.
Fillet welds ( Table J2.5 ) :
Shear on weld metal: Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Table J2.5, page 16.1-100.
Plug and slot welds :
Shear on weld metal: Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Table J2.5, page 16.1-100.
Fillet welds loaded in-plane ( J2.4 ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J2.4, page 16.1-100.
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Tension and shear strength of bolts ( J3.6 ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J3.6, page 16.1-108.
Combined tension and shear in bearing-type connections ( J3.7 ): Per AISC, the omega factor is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J3.7, page 16.1-109.
High-strength bolts in slip-critical connections :
Serviceability limit state ( J3.8 ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J3.8, page 16.1-110. This applies when the " AISC 13th edition limit state for slip-critical bolt design " is set to ' Design all bolts with slip as a serviceability limit state '. It also applies when ' Design as stated in J3.8 ' is selected and the bolt hole is a standard round hole or a slot that is transverse to the load.
Required strength to prevent slip ( J3.8 ): Per AISC, the default omega factor (Ω) is 1.76 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J3.8, page 16.1-110. This applies when the " AISC 13th edition limit state for slip-critical bolt design " is set to ' Design all bolts to prevent slip at the required strength level '. It also applies when ' Design as stated in J3.8 ' is selected and the bolt hole is an oversized hole or a slot parallel to the load.
Bearing strength at bolt holes ( J3.10 ): Per AISC, the default omega factor (Ω) for the design bearing strength at bolt holes is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J3.10, page 16.1-111.
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Tensile yielding ( J4.1 (a) ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J4.1.(a), page 16.1-112.
Tensile rupture ( J4.1 (b) ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J4.1.(b), page 16.1-112.
Shear yielding ( J4.2 (a) ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J4.2.(a), page 16.1-112.
Tensile rupture ( J4.2 (b) ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J4.2.(b), page 16.1-112.
Block shear strength ( J4.3 ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J4.3, page 16.1-112.
Strength in compression ( J4.4 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J4.4, page 16.1-113.
Bearing strength ( J7 ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J7, page 16.1-114.
Column bases and bearing on concrete ( J8 ): Per AISC, the default omega factor (Ω) is 2.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J8, page 16.1-115.
Anchor rods and embedments ( J9 ): Per AISC, the default omega factor (Ω) is 2.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J9, page 16.1-115.
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Flange local bending ( J10.1 ): Per AISC, the default omega factor (Ω) is 1.6 7 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J10.1, page 16.1-116.
Web local yielding ( J10.2 ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J10.2, page 16.1-116.
Web crippling ( J10.3 ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J10.3, page 16.1-117.
Web sidesway buckling ( J10.4 ): Per AISC, the default omega factor (Ω) is 1.76 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J10.1, page 16.1-118.
Web compression buckling ( J10.5 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J10.1, page 16.1-119.
Web panel zone shear ( J10.6 ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section J10.6, page 16.1-119.
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Force distributed transversely :
Round HSS :
Local yielding ( K1.3a ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K1.3a, page 16.1-123.
Rectangular HSS :
Local yielding ( K1.3b (a) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K1.3b.(a), page 16.1-123.
Shear yielding/punching ( K1.3b (b) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K1.3b.(b), page 16.1-123.
Sidewall local yielding ( K1.3b (c) (i) ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K1.3b.(c)(i), page 16.1-124.
Sidewall local crippling ( K1.3b (c) (ii) ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K1.3b.(c)(ii), page 16.1-124.
Sidewall local buckling ( K1.3b (c) (iii) ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K1.3b.(c)(iii), page 16.1-124.
Force distributed longitudinally, perpendicular to axis :
Round HSS ( K1.4a ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K1.4a, page 16.1-125.
Rectangular HSS ( K1.4b ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K1.4b, page 16.1-125.
Axial force on a cap plate :
Wall local yielding ( K1.6 (i) ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K1.6.(i), page 16.1-126.
Wall local crippling ( K1.6 (ii) ): Per AISC, the default omega factor (Ω) is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K1.6.(ii), page 16.1-126.
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Round HSS :
T-, Y-, and cross connections :
Chord plastification in T- and Y-connections ( K2.2b (a) ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.2b.(a), page 16.1-129.
Shear yielding/punching ( K2.2b (b) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.2b.(b), page 16.1-129.
Chord plastification in cross-connections ( K2.2b (c) ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.2b.(c), page 16.1-129.
K-connections :
Chord plastification ( K2.2c (a) ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.2c.(a), page 16.1-129.
Shear yielding/punching ( K2.2c (b) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.2c.(b), page 16.1-130.
Rectangular HSS :
T-, Y-, and cross connections :
Chord wall plastification ( K2.3b (a) ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.3b.(a), page 16.1-132.
Shear yielding/punching ( K2.3b (b) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.3b.(b), page 16.1-132.
Sidewall local yielding ( K2.3b (c) (i) ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.3b.(c)(i), page 16.1-132.
Sidewall local crippling in T- and Y-connections ( K2.3b (c) (ii) ): Per AISC, the default omega factor is 2.00 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.3b.(c)(ii), page 16.1-133.
Sidewall local crippling in cross-connections ( K2.3b (c) (iii) ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.3b.(c)(iii), page 16.1-132.
Local yielding due to uneven load ( K2.3b (d) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.3b.(d), page 16.1-132.
Gapped K-connections :
Chord wall plastification ( K2.3c (a) ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.3c.(a), page 16.1-133.
Shear yielding/punching ( K2.3c (b) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.3c.(b), page 16.1-133.
Local yielding due to uneven load ( K2.3c (d) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.3c.(d), page 16.1-134.
Overlapped K-connections :
Local yielding due to uneven load ( K2.3d ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K2.3d, page 16.1-134.
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Round HSS :
In-plane bending moments :
Chord plastification ( K3.2b (a) ): Per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K3.2b.(a), page 16.1-137.
Shear yielding/punching ( K3.2b (b) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K3.2b.(b), page 16.1-138.
Out-of-plane bending moments :
Chord plastification ( K3.2c (a) ): per AISC, the default omega factor (Ω) is 1.67 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K3.2c.(a), page 16.1-138.
Shear yielding/punching ( K3.2c (b) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K3.2c.(b), page 16.1-138.
Rectangular HSS :
In-plane bending moments :
Chord wall plastification ( K3.3b (a) ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K3.3b.(a), page 16.1-140.
Sidewall local yielding ( K3.3b (b) ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K3.3b.(b), page 16.1-140.
Local yielding due to uneven load ( K3.3c (c) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K3.3b.(c), page 16.1-140.
Out-of-plane bending moments :
Chord wall plastification ( K3.3c (a) ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K3.3c.(a), page 16.1-141.
Sidewall local yielding ( K3.3c (b) ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K3.3c.(b), page 16.1-141.
Local yielding due to uneven load ( K3.3c (c) ): Per AISC, the default omega factor (Ω) is 1.58 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K3.3c.(c), page 16.1-141.
Chord distortional failure ( K3.3c (d) ): Per AISC, the default omega factor (Ω) is 1.50 . Refer to the AISC Steel Construction Manual , Thirteenth Edition, Section K3.3c.(d), page 16.1-141.
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Flexural rupture strength of connection elements ( page 9-6 ): Per AISC, the default omega factor is 2.00 .
Flexural strength of a coped beam ( page 9-6 ): Per AISC, the default omega factor (Ω) is 1.67 .
Flexural yielding strength of an extended configuration shear tab ( page 10-103 ): Per AISC, the default omega factor (Ω) is 1.67 .
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"OK" (or the Enter key) closes the Omega Factors window and saves the settings on it to the Job Settings file in your current Job .
Note: If you have made changes to this window after having added members to the 3D model, you should interactively mark for processing (or Process Selected ) all members in your current Job, then Process and Create Solids , in order to ensure design consistency throughout the Job.
"Cancel" (or the Esc key) closes this window without saving any changes made to it.
"Reset" undoes all changes made to this window since you first opened it. The window remains open.
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