---
title: Run Eurocode Calculations
description: Select load cases, choose your national annex, and let FrameAI run EN 1993, EN 1992, and EN 1998 checks automatically.
category: Get Started
---

## Run Eurocode Calculations

FrameAI automates Eurocode structural checks across steel, concrete, composite, and seismic domains. This guide explains how the calculation engine works and how to interpret the output.

## Supported Eurocode standards

| Standard | Scope |
|----------|-------|
| EN 1993-1-1 | Steel — cross-section classification, member buckling |
| EN 1993-1-8 | Steel — bolted and welded connections |
| EN 1993-1-9 | Steel — fatigue assessment |
| EN 1993-1-10 | Steel — material toughness and Z-quality |
| EN 1992-1-1 | Concrete — RC beams, columns, foundations |
| EN 1994-1-1 | Composite — steel deck + concrete slab beams |
| EN 1998-1 | Seismic — response spectra, q-factor, ductility |
| EN 1991-1-1 | Actions — dead, imposed, crane loads |
| EN 1991-1-3/4 | Snow and wind actions |

## How calculation results are structured

Every job produces a structured result object. The key fields for steel members are:

| Field | Description |
|-------|-------------|
| `member_id` | Part mark from the extracted schedule |
| `profile` | Cross-section (e.g., HEB 300) |
| `length_m` | Effective length in metres |
| `class` | EN 1993-1-1 §5.5 cross-section class |
| `buckling_x` | Flexural buckling utilisation ratio |
| `buckling_z` | Lateral-torsional buckling utilisation ratio |
| `combined` | Interaction formula (6.61/6.62) utilisation |
| `status` | `OK`, `WARNING`, `FAIL` |

```
<div class="screenshot-placeholder">
  📸 Screenshot: The results table showing utilisation ratios and status indicators.
  TODO: replace with actual screenshot
</div>
```

## Cross-section classification

FrameAI classifies each section per EN 1993-1-1 Table 5.2.

For a welded I-section in bending (internal part, Class 1 limits):

```
ε = √(235 / f_y)  where f_y is in MPa
c/t_f ≤ 9ε  → Class 1
c/t_f ≤ 10ε → Class 2
c/t_f ≤ 14ε → Class 3
c/t_f > 14ε → Class 4
```

The effective section properties for Class 4 sections are calculated per EN 1993-1-5.

If you override the material grade, FrameAI recalculates the class automatically.

## Member buckling

FrameAI calculates buckling resistances using:

- Flexural buckling about both axes (EN 1993-1-1 §6.3.1)
- Lateral-torsional buckling for beams (EN 1993-1-1 §6.3.2)
- Imperfection factors α (curve a/b/c depending on section type)
- Slenderness reduction factor χ

The utilisation ratio ξ = N_Ed / N_b,Rd or M_Ed / M_b,Rd should be ≤ 1.0.

```
<div class="screenshot-placeholder">
  📸 Screenshot: The buckling check panel with the α/imperfection factor and χ value.
  TODO: replace with actual screenshot
</div>
```

## Load combinations

FrameAI generates load combinations per EN 1990:

| Combination | Formula |
|-------------|---------|
| Characteristic | 1.35 G + 1.5 Q |
| Frequent | G + ψ1 Q |
| Quasi-permanent | G + ψ2 Q |

The ψ factors are taken from EN 1990 Annex A1, overridden by the National Annex if relevant.

## Understanding warnings

A **WARNING** status means the member is within code limits but approaching a limit (ξ > 0.9). Review the member before approving.

A **FAIL** status means the member exceeds its design resistance. You can:

1. Increase the profile size
2. Reduce the effective length (add lateral restraints)
3. Adjust the connection detail to provide additional stiffness
4. Override the material grade to a higher steel

All overrides are recorded in the job's audit log.

## National annex values

The National Annex tab shows which parameters differ from the EN 1993-1-1 normative values:

```
<div class="screenshot-placeholder">
  📸 Screenshot: The National Annex override panel listing γM0, γM1, α values.
  TODO: replace with actual screenshot
</div>
```

## Exporting calculation results

From the results panel, you can:

- **Download PDF** — full calculation report with formulas, values, and results
- **Download IFC** — model with member metadata including utilisation ratios
- **Share link** — send a read-only view to a client or reviewer

## Next steps

- [Export to Fabrication](/docs/tutorials/export-to-fabrication) — download the fabrication package
- [Shop Drawing PDF](/docs/tutorials/shop-drawing-pdf) — understand what the PDF contains