Verification › V.02 Frames
V.02.27-Storey Steel Moment Frame: Lateral Load
Matches OpenSees, SAP2000, SeismoStruct and STAAD.ProOpen in the app and solveNo sign-up needed: it runs in your browser.
Problem
Find the top-floor sway and the base forces of a 7-storey, 2-bay steel moment frame under lateral loads.
Reference
- SAP2000 Verification Manual (1997), Example 1.
- OpenSeesPy documentation, example "PortalFrame2d".
- SeismoStruct Verification Report (2012), Example 11.
- STAAD.Pro V8i SS6, the same input file run by Sutranet.
Model
- Two bays of 360 in; storeys 162, 162, then five of 156 in
- W14 columns (W14×176 to W14×287) and W24 beams (W24×110 to W24×160), area and inertia only; E 29 500 ksi
- Fixed bases; each floor a rigid diaphragm (the beams carry 10⁵ × their area in the project file)
- Lateral loads 2.5, 5, 7.5, 10, 12.5, 15 and 20 kip at the left column line, floors 1 to 7
Comparison
| Result | OpenSees | SAP2000 | SeismoStruct | STAAD.Pro | Sutranet | Difference |
|---|---|---|---|---|---|---|
| Top sway (in) | 1.45076 | 1.45 | 1.451 | 1.45076 | 1.4507571 | none |
| Base axial force, left column (kip) | 69.987 | 69.99 | 70.01 | 69.99 | 69.9867 | none |
| Base moment, left column (kip-in) | 2324.677 | 2324.68 | 2324.71 | 2324.68 | 2324.6773 | none |
| Result | STAAD.Pro | Sutranet | Difference |
|---|---|---|---|
| Top joint 22, X | 1.45076 | 1.4507571 | none |
| Top joint 22, Y | 0.01771 | 0.0177148 | none |
| Top joint 22, rotation Z | −0.00040 | −0.0004023 | none |
| Member 1 at joint 1: axial | −69.99 | −69.9867 | none |
| Member 1 at joint 1: shear y | 20.67 | 20.6721 | none |
| Member 1 at joint 1: MZ | 2324.68 | 2324.6773 | none |
| Member 1 at joint 4: MZ | 1024.20 | 1024.1999 | none |
| Support 1: FX, FY, MZ | −20.67, −69.99, 2324.68 | −20.6721, −69.9867, 2324.6773 | none |
| Support 2: FX, FY, MZ | −31.16, 0.00, 3145.20 | −31.1558, 0.0000, 3145.1969 | none |
| Support 3: FX, FY, MZ | −20.67, 69.99, 2324.68 | −20.6721, 69.9867, 2324.6772 | none |
- The natural periods and modal masses of the same frame are problem V.04.1.
- In STAAD.Pro the diaphragm was modelled both with SLAVE FX and with axially stiff beams; both print the same, and Sutranet matches both.
Reproduce in Sutranet CAD
- Open the project in the app (no sign-up needed), or download the file and open it with 📂 Import Job JSON in the File group.
- Run Analysis (Static) on load case 2 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: opensees_portal_frame2d.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.