implemented code subset
Three independent section resistances.
This screen follows the Code of Practice for the Structural Use of Steel 2011 (2023 Edition) and the Buildings Department amendment state checked on 12 August 2026, including the April 2026 amendment sheet.
Equations used
Variables: Ag is gross area, Av is shear area, py is steel design strength, S is plastic modulus, Z is elastic modulus, Psec is the independent axial section resistance, Vc is shear capacity, and Mc is major-axis moment capacity. For the supported rolled I/H shear model, Av = tD.
The relevant official clauses are 3.1.2 and Tables 3.1–3.6 for design strength, Table 4.1 for material factors, 7.1–7.2 and Table 7.1 for section classification, 8.6.1 for tension, 8.7.5 and 8.9.1 for gross-section compression terms, 8.2.1 for shear, and 8.2.2.1 for low-shear moment capacity.
Declared limits
- Rolled, doubly symmetric I/H section with user-verified Ag, S, Z, and Av.
- Class 1 plastic or Class 2 compact section; the page does not calculate the Table 7.1 width-to-thickness classification.
- Full lateral restraint to the compression flange and V ≤ 0.6Vc.
- No holes, connection reduction, eccentric connection, plate-girder action, shear buckling, Class 3/4 effective properties, RHS/CHS, cold-formed steel, or composite action.
- Axial and bending actions are displayed independently. If both are entered, the result is REVIEW because the combined interaction equations are outside this release.
- Member compression buckling, lateral-torsional buckling, torsional/flexural-torsional buckling, serviceability, fatigue, fire, connections, and fabrication are separate checks.
The April 2026 amendment sheet changes or clarifies material definitions, welding, vibration, connections, and composite-column provisions. It does not amend the selected Section 7/8 equations used here.