KEVOS® MAKEOS · Mechanics
Wind Load on a Sign or Panel Post (Force, Base Moment, Stress, Deflection)
What wind force does this sign or panel take, what bending stress does it put in the supporting tube post, and how far does the top deflect?
Check of a panel, sign or guard on a single cantilever round-tube post: dynamic pressure, surface pressure, wind force and the base overturning moment (as the wind pressure tool), the post’s second moment and section modulus, bending stress at the base, deflection at the panel centre treating the wind as a point load there, and checks against your allowable stress and deflection limit.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Wind speed | m/s | Design wind speed (gust) at the panel height (from the wind code for the site; your value). |
| Air density | kg/m³ | Air density. |
| Force coefficient | Force (drag) coefficient for the panel shape (about 1.2 for a flat sign; from the wind code). | |
| Panel area | m² | Area of the panel facing the wind. |
| Height of the panel centre above the base | m | Height from the post base to the centre of the panel. |
| Post outside diameter | mm | Outside diameter of the tube post. |
| Post wall thickness | mm | Wall thickness of the post. |
| Post elastic modulus | GPa | Elastic modulus of the post. |
| Allowable bending stress | MPa | Allowable bending stress for the post (your design value). |
| Largest deflection as a fraction of height (1 ÷ …) | Deflection limit expressed as height divided by this number (100 means h/100). |
Method and formulas
- q = ½ ρ V²; p = C_d q; F = p A; base moment M = F h (as the wind pressure tool).
- Tube I = π (D⁴ − d⁴) ÷ 64; Z = I ÷ (D ÷ 2); stress σ = M ÷ Z.
- Deflection at the panel centre δ = F h³ ÷ (3 E I).
- Example: 20 m/s on 2 m² gives 576 N and 1,728 N·m at the base; the post runs at 46.789 MPa and deflects 12.281 mm.
Limitations
- Single post with a rigid base; base plate, bolts and footing need their own checks.
- Wind on the post itself and dynamic (gust) response are not included.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Size a post for a sign, screen or guard
- Check an outdoor panel for a design wind speed
- Check a machine guard against wind or air blast
Who it is for
- Design engineers
- Structural engineers
- Plant engineers
What you get
- Pressure, force and base moment
- Post section and base bending stress
- Deflection at the panel against the limit
Interpreting the result
- Deflection often governs tall single posts before stress does.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 3028, 257–277. Topic reference; no source tables or recommended settings are reproduced.
WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
Open the Wind Load on a Sign or Panel Post (Force, Base Moment, Stress, Deflection) calculator
