Verification › V.02 Frames
V.02.4Member Local Axes in Every Direction
Every tip result matches to the last digitOpen member-axes-y-up in the appOpen member-axes-z-up in the appNo sign-up needed: it runs in your browser.
Problem
Check that member local axes follow STAAD.Pro's convention for every member direction, including vertical members, BETA, and models with Z up.
Reference
- STAAD.Pro V8i SS6, the same input file run by Sutranet (no published solution).
Model
- Sixteen cantilevers pointing in every direction, one rolled by BETA 30
- Different stiffness about each local axis (IY ≠ IZ)
- Tip load FX 1, FY 2, FZ 3 kN; the same model with global Y up and with SET Z UP
Comparison
| Quantity | STAAD.Pro prints to | Largest difference |
|---|---|---|
| Tip displacements, Y up | 0.001 mm | 0.0005 mm |
| Tip rotations, Y up | 0.0001 rad | 0.00005 rad |
| Tip displacements, Z up | 0.001 mm | 0.0005 mm |
| Tip rotations, Z up | 0.0001 rad | 0.00005 rad |
- A member's stiffness about its strong and weak axes decides which way the tip moves, so any axis error shows as a wrong tip displacement. Every difference is within half of STAAD's last printed digit.
Reproduce in Sutranet CAD
- Open the project in the app (no sign-up needed), or download the files and open them with 📂 Import Job JSON in the File group.
- Run Analysis (Static) on load case 1 with P-Delta Analysis unticked.
The app works in SI units; results in kip and inch are converted (1 kip = 4.448 kN, 1 kip-in = 0.1130 kN·m, 1 in = 25.4 mm).
Automated test: staad_import.rs, run on every change.
Run your own models the same way
Create free accountFree account: build frames, trusses and towers, import STAAD .std files, and run IS 800 and AISC design checks in your browser.