AISC 360-16

The AISC 360-16 engine implements the Specification for Structural Steel Buildings (ANSI/AISC 360-16) published by the American Institute of Steel Construction. Both LRFD (Load and Resistance Factor Design) and ASD (Allowable Stress Design) methods are supported.

Open AISC 360-16 Calculator

Standard Reference

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 shows the specific row and clause used for each member result. The documentation keeps the same clause groups at a summary level:

• 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.

Calculator Inputs

The standalone AISC calculator accepts the following inputs. All values are in imperial units.

Design Method

Toggle between LRFD (Load and Resistance Factor Design) and ASD (Allowable Stress Design). This controls which resistance/safety factors are applied to the capacity calculations.

Section Geometry

Select a shape group, then enter dimensions or pick from the built-in section library (AISC shapes database).

Material Properties

Member Lengths & Bracing

A Continuously Restrained checkbox sets L_b = 0, bypassing the LTB check.

Design Actions

Resistance Factors

Limitations & Notes

• Custom-section axis convention: The engine expects section properties in the AutoCalcs strong/weak convention: Izz is major/strong-axis inertia and Iyy is minor/weak-axis inertia. In raw section-library files, Szz/Syy are plastic section modulus values, not elastic Sx/Sy; the loader may expose those plastic values internally as Pzz/Pyy. Displayed/report Sx/Sy elastic values are derived separately from Wel fields or geometry/inertia. Custom or imported sections with these axes swapped can produce incorrect bending, buckling, and LTB axis assignments.
• Slender elements (E7): Uses the AISC 360-16 effective-area path for supported slender compression members, with the result row showing the governing E7 clause.
• Angle LTB (F10): Single-angle LTB follows the applicable F10 branch for the reported bending axis. Users designing single angles near capacity should confirm principal-axis section properties and moment-axis assumptions against the AISC Manual tables.
• Angle H2 stress points: The H2-1 stress-based interaction is evaluated at six fibre points corresponding to the L-section's outer and inner corners (heel, both leg outer/inner tips, and the re-entrant corner). Users designing single angles near capacity should cross-check the principal-axis section properties used by the model against the AISC Manual tables.
• Plate girders (F4/F5): Assumes doubly symmetric I-shapes. Tension flange yielding (F4-15/F5-4) is not checked, since it does not govern for doubly symmetric sections but would be needed for singly symmetric built-up I-shapes with unequal flanges.
• CHS wall thickness: US library sections use the AISC Manual design wall thickness convention in their stored properties. Custom or non-US sections may need manual adjustment.
• C_b factor: Auto-computed from the moment diagram for supported flexural branches and can be overridden. Cantilever cases that require a specific AISC commentary value should be reviewed and overridden where applicable.
• Net section: Tension rupture follows D2/D3 using default shear-lag assumptions. Actual bolt holes, staggered hole paths, connection length, and detailed shear-lag geometry are not modelled; final tension-member connection regions should be checked separately where net area governs.
• Concentrated forces and reactions: The AISC member engine does not perform AISC J10 local checks or derive them from FEA reactions, point loads, or connection forces. This includes flange local bending, web local yielding, web crippling, web sidesway buckling, bearing stiffeners, and doubler plate requirements at supports, point loads, and connection force-transfer regions. Check these separately from the member-strength result.
• Bracing design: The engine uses user-specified effective lengths, unbraced lengths, and restraint assumptions. It does not verify brace strength, brace stiffness, diaphragm stiffness, or whether lateral bracing is attached to the correct flange for a specific member/loading case.
• Torsion: Applied torsion is not an input in the standalone calculator, so H3 torsion checks run in the FEA tool only. Compression-member E4 torsional buckling is still checked for supported section families. Warping torsion for open sections (I-beams, channels, angles, tees) is not performed.
• 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 78 independent verification cases from the AISC Design Examples v15.0 with an average difference of 0.15%. Checks cover classification, tension, compression, flexure (including LTB and FLB), shear, C_b factor computation, and biaxial interaction.