Steel · Connections: moment & splices
Bolted moment end plate (extended, 8.8/TB) calculator
Extended end plate on a UB beam framing into a UC column flange. The flange force M*/(d − tf) goes to the two bolt rows either side of the tension flange; each row is checked as a T-stub (mode 1 plate yield, mode 2 yield with bolt prying, mode 3 bolt fracture) for both the end plate and the column flange. Bolt shear-tension interaction, flange and web welds and column web panel shear complete the check.
Standard: AS 4100-2020 Cl 9.2 bolts, Cl 9.6 welds · T-stub yield-line model (EN 1993-1-8 Cl 6.2.4) · ASI connection design guides
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 |
|---|---|---|
| Beam | 460UB74.6 | |
| Column | 310UC118 | |
| Design moment M* | 220 | kNm |
| Design shear V* | 150 | kN |
| Bolts (8.8/TB) | M24 | |
| Total bolts (incl. 2 shear bolts at the bottom) | 10 | |
| End-plate thickness | 25 | mm |
| Plate fy | 250 | MPa |
| Plate width | 200 | mm |
| Bolt gauge | 110 | mm |
| Bolt centre to flange face | 50 | mm |
| Flange fillet weld leg | 10 | mm |
| Web fillet weld leg | 6 | mm |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| Flange force Ff = M*/(d − tf) | 497 | kN |
| Bolt φNtf / φVf (threads in) | 234.4 / 133.4 | kN |
| End plate T-stub: m / n / leff | 38.7 / 45.0 / 200 | mm |
| End plate per row F1 / F2 / F3 | 727 / 420 / 469 kN → mode 2 (yield + prying) | |
| Column flange per row | 397 kN, mode 2 (yield + prying) | |
| Tension capacity of the two rows | 794 | kN |
| Bolt interaction (V/φVf)² + (N/φNtf)² | 0.29 | |
| Bolt bearing on plate φVb | 708 | kN |
| Flange weld v* / φvw | 1.34 / 1.66 | kN/mm |
| Web weld v* / φvw | 0.18 / 1.00 | kN/mm |
| Column web panel φVpz | 567 | kN |
- ✓ Ff ≤ two-row T-stub capacity — 63 %
- ✓ Bolt shear–tension interaction ≤ 1
- ✓ Bolt bearing
- ✓ Flange welds
- ✓ Web welds
- ✓ Column web panel shear — 88 %
- ✓ Edge distance (bp − g)/2 ≥ 1.5df
Method, formulas and assumptions
- T-stub per bolt row (two bolts): leff = min(2·min(2πm, 4m + 1.25e), width); Mpl = 0.25·leff·t²·fy (φ = 0.9); F1 = 4Mpl/m, F2 = (2Mpl + nΣφNtf)/(m + n), F3 = ΣφNtf.
- m measured from the bolt to 0.8 × the weld leg (or root radius) and n = min(e, 1.25m). Prying is captured by mode 2.
- Bolts 8.8/TB: φNtf = 0.8·As·fuf, φVf = 0.8 × 0.62·fuf·Ac (threads in the shear plane). Welds E49XX SP: φvw = 0.8 × 0.6 × 490·tt.
- Column web compression/stiffeners not checked here; add stiffeners opposite the beam flanges when the column web or flange governs.
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.