| Standard | Title | Reference Tools | Reference Table |
|---|---|---|---|
| EN 1999-1-1 | General structural rules | - | - |
| EN 1999-1-2 | Structural fire design | - | - |
| EN 1999-1-3 | Structures susceptible to fatigue | - | - |
| EN 1999-1-4 | Cold-formed structural sheeting | - | - |
| EN 1999-1-5 | Shell structures | - | - |
What this standard covers
EN 1999 (Eurocode 9 - Design of aluminium structures) covers structural aluminium alloys: member design, connections, fatigue, fire and cold-formed sheeting.
EN 1999-1-1 gives the general structural rules, EN 1999-1-2 fire, EN 1999-1-3 structures susceptible to fatigue, EN 1999-1-4 cold-formed sheeting and EN 1999-1-5 shell structures. The framework follows EN 1993 for steel closely - cross-section classification, buckling curves and the same limit-state format - so a designer familiar with steel will recognise the structure of the checks.
The differences from steel matter more than the similarities. Aluminium has roughly a third of the modulus of steel, so deflection and buckling govern far more often. Welding softens the material in a heat-affected zone next to the weld, which has to be allowed for explicitly. And the alloy and temper, not a single grade designation, determine strength.
What you will find in it
- Alloys and tempers
- The wrought alloys and temper designations used structurally, and the characteristic strengths that follow from each combination.
- Heat-affected zone
- The local softening of the material adjacent to a weld, its extent, and the reduced strength that must be used within it.
- Cross-section classification
- Classes 1 to 4 as in steel design, with the local buckling and the treatment of internal and outstand elements adapted to aluminium.
- Member buckling
- Flexural, torsional and lateral-torsional buckling, more often decisive than in steel because of the lower modulus.
- Connections
- Bolted, riveted, welded and adhesive-bonded joints, with the weld design accounting for the heat-affected zone.
- Fatigue
- Detail categories and the assessment of structures under repeated loading, covered by EN 1999-1-3.
When to use this standard
Use EN 1999 for load-bearing aluminium structures and components - facade and curtain-wall framing, walkways, lightweight roofs, access structures and transport-related structures. Do not apply EN 1993 resistance rules to aluminium: the buckling behaviour, the heat-affected zone and the fatigue treatment are specific to this material.
How it fits with the other standards
Actions are established by EN 1991 and combined under EN 1990. The overall framework mirrors EN 1993 for steel, and seismic design follows EN 1998.
What each part covers
- EN 1999-1-1
- The general structural rules: alloys and tempers, cross-section classification, member resistance and buckling, and the heat-affected zone adjacent to welds.
- EN 1999-1-2
- Structural fire design. Aluminium loses strength at markedly lower temperatures than steel, so fire is often more onerous for it.
- EN 1999-1-3
- Structures susceptible to fatigue. Detail categories and fatigue assessment, important because aluminium is used in transport and machinery structures under repeated load.
- EN 1999-1-4
- Cold-formed structural sheeting. Thin-gauge aluminium sheeting, with the effective-width treatment its local buckling requires.
- EN 1999-1-5
- Shell structures. Curved aluminium shells, whose buckling is imperfection-sensitive in the same way as steel shells.