Eurocode 3 truss design to EN 1993-1-1
TrussLab checks every truss member to EN 1993-1-1 for each ULS combination, with European sections (IPE, HE, UPN, UPE, angles and hollow sections) in S235 to S460 and a step-by-step calculation report per member.
Limit states checked to EN 1993-1-1
Every truss member is checked for each strength load combination. The governing combination and limit state are reported per member as a demand-capacity ratio (DCR), and members are colored by DCR in the model view.
| Limit state | EN 1993-1-1 clauses |
|---|---|
| Tension | 6.2.3 |
| Compression | 6.2.4, 6.3.1 |
| Flexure | 6.2.5, 6.3.2.2 |
| Shear | 6.2.6, EN 1993-1-5 5.2 |
| Combined forces | 6.2.1(7), 6.3.3 (Annex B) |
Partial factors are the recommended values γM0 = γM1 = 1.0. A class 4 tee stem is taken with the effective section of EN 1993-1-5.
Sections and steels
European catalogue (EN 10365, EN 10056-1, EN 10210-2, EN 10219-2): IPE, HEA, HEB, HEM, UPN, UPE, L, double L, and SHS, RHS and CHS, hot-finished and cold-formed. Steels: S235, S275, S355 and S460.
Members are grouped (top chord, bottom chord, diagonals, verticals), each group is assigned a catalogue section and one of the standard steels, and individual members can be overridden. Auto-design selects sections that pass the checks; the optimizer also varies geometry and topology.
Calculation report
A step-by-step calculation report is generated for each member, per limit state and governing load combination, with the demand, the design strength and the resulting DCR. The full truss report is exported as PDF.
Verification against published EN 1993-1-1 examples
Resistances are compared with Gardner & Nethercot's Designers' Guide to EN 1993-1-1, the bauforumstahl design aid Columns in Multi-Storey Construction, Trahair, Bradford, Nethercot & Gardner's Behaviour and Design of Steel Structures to EC3, and the EC3 verification problems of STAAD.Pro. The test suite checks 110 flexural buckling resistances of the bauforumstahl tables (HE A, HE B and HE M, 2 to 10 m, both axes), all within 0.5 %.
The inputs, reference values, TrussLab values and differences are listed on the verification page, with downloadable project files.
Scope and differences from the code examples
- Lateral-torsional buckling uses the general case (6.3.2.2) with C1 = 1.0 and the load at the shear centre.
- Root radii are not part of the catalogue rows; shear areas and classification c/t ratios are taken without them, which is conservative.
- Combined compression and bending under 6.2.9 uses the linear criterion of 6.2.1(7) instead of the reduced plastic moment MN,Rd.
- Analysis is linear elastic and static. Connections are not designed.
Frequently asked questions
Which National Annex is used?
The recommended values of EN 1993-1-1 are used, with γM0 = γM1 = 1.0.
Are hollow section trusses supported?
Yes. SHS, RHS and CHS sections, hot-finished (EN 10210-2) and cold-formed (EN 10219-2), are in the European catalogue.
Can the design code be changed after the model is built?
Yes. The design code is a project setting. Selecting another code re-runs the member checks and sets that code's default load combinations; the geometry and loads are kept. Any code can be used with any section catalogue.
Are connections designed?
No. TrussLab designs members only. A selected joint with its connected members and forces is exported to IDEA StatiCa Connection for connection design.