Design Code Checks

Run steel member capacity checks directly on analysed members within Structural FEA. Design checks are accessed through the Design Check tab in the Member Analysis dialog. Available to all users with monthly usage limits (3 anonymous, 10 free, unlimited Pro).

Supported Design Codes

Code	Region	Design Methods
AISC 360-16	United States	LRFD / ASD
AISC 360-22	United States	LRFD / ASD
Eurocode 3 (EN 1993-1-1)	Europe	Limit State
AS 4100:2020	Australia	Limit State
CSA S16-19	Canada	Limit State

Accessing the Design Check Tab

Run the analysis - design checks require valid analysis results.
Select a member in the 3D view.
Open Member Analysis - right-click the member and choose "Member Analysis", or click the Member Analysis button in the Properties panel.
Switch to the Design Check tab.

How It Works

The Design Check tab takes the internal forces from the FEA results and checks the selected member against the chosen design code. Forces are extracted automatically from the analysis - you do not need to input them manually.

The check uses the member's assigned section properties (from the library) and material properties, along with the internal force envelope or a specific load combination.

Combo Mode

Selected - Check against the currently selected load combination only.
Envelope - Check against all load combinations and report the governing result. This is the recommended mode for final design verification.

Design Parameters

The following parameters can be configured before running a check:

Effective Length Factors

Ky - Effective length factor for the weak/minor buckling mode (default 1.0)
Kz - Effective length factor for the strong/major buckling mode (default 1.0)
KLT - Effective length factor for lateral-torsional buckling (default 1.0)
Kt (AISC) - Independent effective length factor for Chapter E4 torsional/flexural-torsional buckling (default 1.0)

The effective buckling length is K × L, where L is the member length. Code-axis symbols vary: for example, EC5 calls its strong axis y and weak axis z, so the timber reports map app K_z to l_e,y and app K_y to l_e,z.

Lateral Restraint

Full Lateral Restraint - When enabled, the lateral-torsional buckling check is skipped. Use this when the compression flange is continuously braced (e.g. by a concrete slab or metal decking).

Moment Factor Override

Each design code uses a moment gradient factor to account for non-uniform bending moment distributions along the member:

AISC 360-16 / AISC 360-22: C_b (Eq. F1-1)
Eurocode 3: C₁ (NCCI SN003)
AS 4100:2020: α_m (Cl 5.6.1.1)
CSA S16-19: ω₂ (Cl 13.6)

By default, the factor is computed automatically from the member's moment diagram. You can override it if you have a specific value from your engineering judgement or a more detailed analysis.

Tension Rupture Inputs

Hot-rolled steel checks accept a member net tension area. AISC and CSA also accept a shear-lag/effective-net factor, while AS 4100 accepts k_t. Blank net area defaults to gross area; the member engine does not derive holes, staggered paths, or connection geometry.

Code-Specific Options

Load Height (EC3, AS4100) - Whether the load is applied at the shear centre or the top flange. Top flange loading is more conservative for lateral-torsional buckling.
AS4100 imported metadata - k_f, α_b, and β_x are normally derived from the section and code rules. Imported models may carry explicit values for replaying known section metadata; these are not ordinary required manual inputs.
M_cr / k_c,LT (EC3) - Optional elastic critical moment override for EC3 LTB, plus a Table 6.6 correction factor for the 6.3.2.3 I/H method only.
Cantilever (AISC, AS4100, CSA) - AISC forces C_b = 1.0 and CSA forces ω₂/ω₃ = 1.0 while enabled. AS 4100 also provides load type selection (end moment, point load, or UDL).
AS4100 Table 5.6.3 - Segment restraint, load position, and rotation factors apply only after the table-factor control is explicitly activated; otherwise KLT is treated as the final L_e/L factor.
AS4100 channel FTB brace confirmation - Confirms the hot-rolled channel is braced about its minor principal axis, which triggers the engine-local Clause 6.3.3 FTB force capacity using the referenced equations, the 0.85 reduction, and phi=0.90. An unbraced hot-rolled channel remains on ordinary flexural buckling.
EC3 partial factors - γ_M0, γ_M1, and γ_M2 may be overridden for the applicable National Annex and are printed in the PDF settings.
Design Method (AISC) - Toggle between LRFD and ASD.

Results

After running a check, the Design Check tab displays:

Overall Status - Pass, Warning, or Fail with a colour-coded indicator.
Utilisation Ratio - The governing demand-to-capacity ratio as a percentage.
Governing Check - The name and clause of the most critical check.
Governing Combination - Which load combination produces the worst result (in envelope mode).

Individual Check Results

A detailed table lists every capacity check performed:

Check Name - e.g. "Lateral-Torsional Buckling (F2)", "Axial Compression (E3)"
Demand - The applied force or moment from the analysis
Capacity - The calculated member resistance
Ratio - Demand / Capacity (values above 1.0 indicate failure)
Status - Pass, Warning, or Fail

Checks Performed

Depending on the design code and section type, checks include:

Section classification (compact/non-compact/slender or Class 1 to 4)
Axial tension and compression, including code-specific member stability checks
Flexure - yielding, lateral-torsional buckling, flange and web local buckling
Shear - web yielding
Torsion - for closed hollow sections (RHS/SHS/CHS)
Combined actions - axial + biaxial bending interaction

PDF Hand Calculations

Export a detailed PDF for the published design checks and visible blocking scope results. The handcalc report includes section properties, applied forces, design settings, available intermediate values, clause references, and final capacity ratios for independent engineering review.

Warnings

The design engine may produce advisory warnings alongside the check results. These highlight situations where the results should be reviewed with care:

Slenderness ratio exceeds code limits
Section classification changes under combined loading
Effective width reductions applied for slender elements
Torsion not checked for open sections (warping torsion not implemented)
The AISC cantilever switch forces C_b = 1.0 and ignores a typed override; turn it off only when applying a rational cantilever LTB result through the manual inputs
EC3 cantilever LTB cases should have C₁, L_b/KLT, and load-height assumptions checked separately because fixed-free boundary conditions are not auto-detected
The CSA cantilever switch forces ω₂/ω₃ = 1.0 and ignores a typed override; turn it off only when applying a rational cantilever LTB result through the manual inputs

Supported Section Types

All hot-rolled steel design codes support the following section shapes from the library:

I-Sections - Rolled and welded (UB, UC, W-shapes, doubly-symmetric and mono-symmetric)
Channels - PFC, C-shapes
Tee Sections - BT, WT
Rectangular Hollow Sections - RHS, SHS
Circular Hollow Sections - CHS, pipe
Angles - Equal and unequal

Limitations

Warping torsion for open sections is not checked - torsion checks apply to closed hollow sections only.
Effective length factors must be user-specified. The FEA does not automatically calculate system-level buckling lengths.
Support, point-load, and connection-region local checks are not automatically derived from the model. Examples include concentrated-force web checks, bearing stiffeners, doubler plates, local flange bending, and web crippling.
Connection design is separate from member design. A passing member check does not verify bolt holes, connection net sections, welds, bolts, brace attachments, or transfer-region detailing unless a separate connection check is run.
Brace and restraint design is separate from member design. The check uses effective lengths, unbraced lengths, load-height settings, and full-restraint flags as inputs; it does not verify brace strength, stiffness, diaphragm action, or restraint connection capacity.
Compound member detailing such as laced, battened, back-to-back, or multi-component member interconnections is not automatically generated unless stated in the code-specific documentation.
Built-up and fabricated section support varies by code and section type. AISC includes selected built-up I-shape and plate-girder provisions; verify the code-specific documentation before relying on fabricated-section results.
Ponding, fatigue, fire, corrosion, composite action, seismic detailing, and serviceability limits are outside the steel member-strength checks unless covered by another tool or workflow.

Standalone Design Calculators

The same design engines are also available as standalone calculators, where you can input member forces directly without building a full FEA model: