Calculator Inputs
Formula Used
The calculator converts one concentrated force into an equivalent distributed load over a chosen length. The total force remains the same.
| Item | Formula | Meaning |
|---|---|---|
| Design point load | Pd = P × SF |
Applies the safety factor to the entered point load. |
| Equivalent patch intensity | w = Pd / a |
Spreads the same force over the selected loaded length. |
| Full-span equivalent intensity | wfull = Pd / L |
Spreads the force over the whole beam span. |
| Force check | Pd = w × a |
Confirms that the distributed load preserves the original resultant. |
| Support reactions | RA = Pd(L - x̄)/L, RB = Pdx̄/L |
Uses the equivalent load centroid position x̄. |
Here, P is the original point load, SF is the safety factor, a is the distribution length, and L is the beam span.
How to Use This Calculator
- Enter the original point load value.
- Set the safety factor for design conditions.
- Enter the beam span.
- Enter the load position from the left end.
- Set the distribution length for the equivalent patch load.
- Choose whether the patch starts, ends, centers, or spans fully.
- Select force and length units.
- Click Calculate to see the result, chart, and downloadable report.
Example Data Table
| Case | Point Load | Span | Distribution Length | Equivalent Intensity | Mode |
|---|---|---|---|---|---|
| Lab beam | 12 kN | 4 m | 1 m | 12 kN/m | Centered |
| Machine seat | 25 kN | 6 m | 1.5 m | 16.67 kN/m | Centered |
| Short bearing plate | 18 kN | 5 m | 0.6 m | 30 kN/m | Start at load |
| Full span comparison | 18 kN | 6 m | 6 m | 3 kN/m | Full span |
| Edge conversion | 10 kN | 3 m | 1.2 m | 8.33 kN/m | End at load |
FAQs
1. What does this calculator convert?
It converts a concentrated point load into an equivalent distributed load over a chosen length. Both loading patterns carry the same total resultant force.
2. Why does a shorter distribution length raise intensity?
The same force is applied over less distance. Since intensity equals force divided by loaded length, reducing the length increases the distributed load value.
3. What is the difference between patch load and full-span load?
A patch load acts only over part of the beam. A full-span load spreads the force across the entire span, producing a much lower intensity.
4. Does this preserve total force?
Yes. The calculator checks that distributed intensity multiplied by the effective loaded length equals the design point load.
5. Why are reactions included?
Support reactions help you compare how the equivalent distributed load affects a simply supported beam. They are based on the centroid of the distributed patch.
6. Can I place the distributed patch near an edge?
Yes. The calculator shifts the patch inside the beam limits whenever a selected distribution would otherwise extend beyond the span.
7. When should I use a safety factor?
Use a safety factor when designing for uncertainty, code requirements, or conservative checks. The calculator multiplies the entered point load by this factor first.
8. Is this a replacement for full structural analysis?
No. It is a fast engineering aid for equivalent loading estimates. Final design should still follow governing codes, material limits, and full beam analysis.