Beam Design: Run Analysis & View Diagrams
Run the beam solver and interpret shear/moment/deflection diagrams and design checks.
The Beam Design analyzer is the simple-span solver behind ClearSpan's beam tools. You describe the beam, apply load patterns combined into factored load cases, and it returns shear (V), moment (M), and deflection (δ) along the span plus support reactions. A wood beam capacity check then turns those demands into DCRs against a chosen member.
Set up the analysis#
A beam design is built from four pieces:
| Input | What it is |
|---|---|
| Beam | The span and stiffness — length, modulus of elasticity (E), and moment of inertia (I). |
| Load patterns | Named groups of loads. Each load is point (P at position x) or uniform (w over the span), tagged with a category (Dead, Live, …). |
| Load combinations | Factored combos, e.g. 1.2D + 1.6L, mapping category factors. |
| Load cases | Each pairs one or more patterns with one combo to form a single demand case (e.g. "Gravity - Factored"). |
Build the loads with the area- and point-load helpers so you don't multiply tributary areas by hand — see Area & Point Loads. You can seed a fresh design's combinations and deflection limits from the project's Design Criteria.
Run it and read the outputs#
Running the analysis produces, per load case:
- V (shear), M (moment), and deflection envelopes along the span — including the max/min value and the position x where each occurs.
- Support reactions (R1, R2) for each case — these feed linked posts. See Link Loads to a Calc.
- Full shear / moment / deflection diagrams in the editor, rendered from the solver's point-by-point arrays.
When the analysis runs through the AI assistant or MCP connector, the large point-by-point V/M/deflection arrays are omitted from the response to keep the conversation compact — open the calc in the Beam Design editor to view the diagrams. See MCP Runner Tools.
Design checks and DCRs#
The analysis gives you demand (V, M, δ). To get demand-to-capacity ratios you pair it with a member:
- In a wood beam capacity check, the solver compares each case's M, V, and δ against the selected section's capacity and reports a Bending DCR, Shear DCR, and Deflection DCR. Any DCR over 1.0 fails.
- The controlling case is the one with the worst DCR across the three checks; the page surfaces it in the envelope strip.
- A per-case deflection limit (e.g. L/360) can be set to drive the deflection DCR.
For the member side of the check, see Wood Beam Calcs; to put the analysis into a deliverable, see Reports.