AISC 360-22
The AISC 360-22 engine implements member-strength checks from Specification for Structural Steel Buildings (ANSI/AISC 360-22) for standalone steel member checks and the Structural FEA design workflow. Both LRFD (Load and Resistance Factor Design) and ASD (Allowable Stress Design) methods are supported.
Open AISC 360-22 Calculator - Verification report
Standard Reference
| Standard | ANSI/AISC 360-22 (2022) |
| Design Methods | LRFD and ASD |
| Units | Imperial design-code units: kips, kip-in, ksi, in |
| Verification Source | AISC Manual Companion v16.0, Volume 1: Design Examples |
| Verification Cases | 42 verification cases, 0.35% average difference |
Supported Section Types
- I-Shapes (W, S, M, HP - rolled and built-up/welded)
- Channels (C, MC)
- Tees (WT, ST, MT - beam and column tees)
- Rectangular Hollow Sections (HSS rectangular and square)
- Circular Hollow Sections (Pipe, HSS round)
- Angles (equal and unequal leg)
Checks Performed
The design-check table reports the specific result row and clause used for each member result. At a summary level, the AISC 360-22 member engine covers:
- Section classification (Table B4.1): Compression and flexural element classes are reported separately where they affect member checks.
- Tension (D2/D3): Gross yielding and effective-net-section rupture are checked; detailed bolt-hole paths are not inferred.
- Compression (E3/E4/E5/E7): Flexural, torsional, flexural-torsional, single-angle, and slender-element paths are used where the section family supports them.
- Flexure (F2-F12): Yielding, LTB, local buckling, HSS, tee, and single-angle flexural paths are selected by section family and axis.
- Shear (G2-G6): Web, flange, HSS, tee-stem, and single-angle shear rows report the applicable local shear path.
- Combined actions and torsion (H1/H2/H3): Axial-plus-bending interaction is evaluated at member stations; closed-HSS torsion rows are reported when applied torsion is available.
Implemented 360-22 Deltas
- F6 minor-axis slender flange local buckling: uses the AISC 360-22 coefficient
0.70E/(b/tf)^2. - H3-6 HSS torsion interaction: uses both major- and minor-axis flexure ratios and takes
Vr/Vcas the larger x- or y-axis shear ratio. - F7 rectangular HSS and box flexure: the 360-22 equation format is algebraically equivalent to the implemented effective-section path.
Design Inputs
AISC 360-22 can be used from the standalone calculator with manually entered design actions. In the Structural FEA workflow, section geometry and material properties come from the member's assigned section/material data, while design parameters are supplied per member.
Design Method
Select LRFD or ASD. The same member checks run in both methods, with the result rows using the appropriate resistance or safety factors.
Material Properties
| Symbol | Description | Unit |
|---|---|---|
Fy | Minimum yield stress | ksi |
Fu | Minimum tensile strength | ksi |
Member Lengths And Bracing
| Input | Description | Unit/Basis |
|---|---|---|
Ky | Compression effective length factor about the weak/minor axis. The effective length is Ky x L and pairs with Iyy. | - |
Kz | Compression effective length factor about the strong/major axis. The effective length is Kz x L and pairs with Izz. | - |
Lb | Unbraced length for lateral-torsional buckling between points braced against lateral displacement or twist. | member design length unit |
Cb | Lateral-torsional buckling modification factor. Blank = auto from the moment diagram; tee LTB uses Cb = 1.0, and AISC F10 angle checks cap Cb at 1.5. | - |
KLT | FEA-tab helper factor where Lb = KLT x L when restraint spacing is entered through the helper. | - |
Design Actions
| Action | Description | Sign Convention |
|---|---|---|
P | Design axial force envelope | Compression and tension paths are selected from the active member demand. |
Mz | Strong/major-axis bending moment | Used with the AutoCalcs strong-axis convention. |
My | Weak/minor-axis bending moment | Used with the AutoCalcs weak-axis convention. |
Vz | Major-axis shear demand | Used by the applicable web or HSS shear path. |
Vy | Minor-axis shear demand | Used by flange, HSS, angle, and H3 torsion interaction paths where applicable. |
T | Torsion demand | Checked for closed HSS/pipe torsion rows when available. |
Resistance Factors
| Check | LRFD (φ) | ASD (Ω) |
|---|---|---|
| Tension (yielding) | 0.90 | 1.67 |
| Tension (rupture) | 0.75 | 2.00 |
| Compression | 0.90 | 1.67 |
| Flexure | 0.90 | 1.67 |
| Shear | 0.90 or 1.00 where the specification permits | 1.67 or 1.50 where the specification permits |
Limitations & Notes
- Member-strength scope: classification, tension, compression, flexure, shear, closed-HSS torsion, and combined actions are checked. Connection design is outside this member engine.
- Connection/detail inputs not inferred: D3 HSS shear-lag Cases 5/6, D5 pin-connected members, D6 eyebars, and F13 bolt-hole proportioning require connection geometry and remain separate checks. HSS tension rupture currently reports a visible limitation and uses the member placeholder
U=0.75withAn=Aguntil connection geometry is available. - Member/detail geometry not inferred: E4(d)/(e) offset lateral bracing, G2.3 end-panel tension-field action, G2.4 stiffener design, and F11 rectangular bars/rounds require inputs or section families not present in this member tab.
- Custom-section axis convention: the engine expects the AutoCalcs strong/weak convention:
Izzis major/strong-axis inertia andIyyis minor/weak-axis inertia. Swapped axes can produce incorrect bending, buckling, and LTB assignments. - Net section: tension rupture can use supplied effective net area where available, but bolt holes, staggered paths, connection length, and detailed shear-lag geometry are not inferred from the member model. Check the actual connection net section separately where rupture can govern.
- Concentrated forces and reactions: AISC J10 local checks are not derived from FEA reactions, point loads, or connection forces. Check flange local bending, web local yielding, web crippling, web sidesway buckling, bearing stiffeners, and doubler plates separately.
- Bracing design: effective lengths, unbraced lengths, restraint assumptions, and Cb overrides are design inputs. The engine does not verify brace strength, brace stiffness, diaphragm stiffness, or attachment location.
- Torsion: H3.1/H3.2 closed-HSS torsion is checked where torsion demand is available. H3.3 non-HSS/open-section warping torsion is outside the current member-force model.
- Scope exclusions: ponding, fatigue, fire design, corrosion allowance, composite member design, seismic detailing/proportioning, and serviceability limits are outside this AISC member-strength engine unless handled by a separate workflow.
Verification
The engine is checked against 42 AISC Manual Companion v16.0 rows with an average difference of 0.35%. The suite covers Chapter D tension, Chapter E compression, Chapter F flexure, Chapter G shear, and Chapter H interaction/torsion examples.