Calculator Inputs
Enter beam geometry, supports, loads, and the applied moment. Use kN, m, kN/m, and kN·m units throughout.
Example Data Table
This sample shows a ready-to-test case for the solver.
| Beam (m) | A (m) | B (m) | P1 (kN) | x1 (m) | P2 (kN) | x2 (m) | UDL (kN/m) | UDL Start | UDL End | Moment (kN·m) | Moment Pos | RA (kN) | RB (kN) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 10.00 | 1.00 | 9.00 | 12.00 | 2.50 | 9.00 | 7.00 | 1.50 | 4.00 | 8.00 | 4.00 | 6.00 | 13.750 | 13.250 |
Formula Used
The solver assumes a statically determinate beam with two vertical reactions. Clockwise applied moment is entered as positive.
How to Use This Calculator
- Enter the full beam length.
- Place Support A and Support B along that beam.
- Add up to two point loads and their positions.
- Enter a UDL intensity and its loaded range.
- Add an applied moment if your case includes one.
- Click the solve button to compute RA and RB.
- Review the equilibrium checks and graph outputs.
- Download CSV or PDF for reporting or teaching notes.
Frequently Asked Questions
1) What does this support reaction solver calculate?
It calculates the two vertical support reactions for a beam with two supports. It also estimates the combined vertical resultant, shear force curve, bending moment curve, and equilibrium checks.
2) Can this handle an offset support layout?
Yes. Support A and Support B can be placed anywhere inside the beam length, as long as A stays left of B. This lets you model overhangs and unequal support spacing.
3) How is the UDL treated in the calculation?
The UDL is converted into a single equivalent downward force. That resultant acts at the center of the loaded segment, then the solver applies equilibrium equations to find reactions.
4) Why might a reaction value become negative?
A negative reaction means the support would need a downward hold-down force instead of a simple upward bearing force. This often happens with strong moments or heavy overhang loading.
5) Does the moment location affect support reactions?
For a free applied couple, the location does not change the reaction values in a rigid equilibrium sense. The location is still useful for plotting the bending moment jump.
6) What units should I use?
Use one consistent unit system. This template assumes meters for distance, kilonewtons for point loads, kilonewtons per meter for UDL, and kilonewton-meters for moments.
7) Is this suitable for indeterminate beams?
No. This page is for statically determinate reaction solving with two vertical supports. Indeterminate systems require stiffness, compatibility, or matrix-based structural methods.
8) What should I check before trusting the answer?
Verify support locations, load directions, beam length, and moment sign. Then confirm the displayed force and moment checks are very close to zero before using the results.
Why This Tool Helps
This calculator is useful for physics lessons, statics practice, structural screening, and fast documentation. It combines equilibrium solving, charting, downloadable reporting, and a clean example table in one page.