Timber · Beams & joists
Timber beam shear calculator
Shear capacity with As = (2/3) b d for rectangular sections.
Standard: AS 1720.1 Cl 3.2.5
Inputs in the worked example
The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.
| Input | Value | Unit |
|---|---|---|
| Breadth | 45 | mm |
| Depth | 240 | mm |
| Characteristic shear f′s | 3.8 | MPa |
| Capacity factor φ | 0.85 cat 2 | |
| Duration k1 | 0.8 (5 months) | |
| Moisture k4 | 1 | |
| Temperature k6 | 1 | |
| Design shear V* | 14 | kN |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| As = 2bd/3 | 7,200 | mm² |
| φVd = φ k1 k4 k6 f′s As | 18.60 | kN |
- ✓ V* ≤ φV
Method, formulas and assumptions
- As = 2bd/3 = 2*45*240/3 = 7200 mm²
- φVd = φ k1 k4 k6 f′s As = 0.85*0.8*1*1*3.8*7200/1000 = 18.605 kN
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.