Steel · Connections: moment & splices

Flush end plate moment connection calculator

Bolt tension from elastic distribution about the compression flange, end plate thickness from a double-curvature T-stub, flange welds and shear bolts. Also suits apex joints.

Standard: AS 4100 Cl 9.3, 9.7 · T-stub plate bending (simplified)

Open the live calculator → All steel calculators

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
Design moment M*	120	kNm
Design shear V*	90	kN
Beam depth	360	mm
Beam flange thickness	11.5	mm
Beam flange width	171	mm
Bolt row 1 lever arm (from comp. flange centre)	290	mm
Bolt row 2 lever arm	210	mm
Bolt row 3 lever arm (0 if none)	0	mm
Bolt to weld toe distance m	40	mm
Effective plate width per bolt p	85	mm
Bolt size	M24
Bolt category	8.8/TB
Plate grade	Grade 250 plate
End plate thickness	25	mm
Flange fillet weld leg	10	mm
Weld category	SP (φ = 0.8)

Worked example — results

Result	Value	Unit
Bolt diameter df	24.00	mm
Bolt tensile strength fuf	830.0	MPa
Tensile stress area As	353.0	mm²
Core area Ac (threads)	324.0	mm²
Shank area Ao	452.0	mm²
Plate yield stress fy (AS/NZS 3678)	250.0	MPa
Plate tensile strength fu	410.0	MPa
Σ 2 r² (two bolts per row)	256,400	mm²
Top bolt tension M r1/Σ2r²	135.7	kN
φNtf	234.4	kN
Plate thickness required √(2 T m/(φ fy p))	23.83	mm
Number of bolts (tension rows + 2 shear bolts)	6.00
Shear per bolt (all bolts)	15.00	kN
φVf (threads included)	133.4	kN
Flange force M/(d − tf)	344.3	kN
Flange weld capacity (both sides of flange)	568.8	kN
Bolt interaction (V/φVf)² + (N/φNtf)²	0.348
Limit	1.00

✓ Bolt tension + shear interaction
✓ End plate thickness
✓ Flange welds

Diagram for the worked example

Method, formulas and assumptions

Bolt diameter df = CHOOSE(4,12,16,20,24,30,36) = 24 mm
Bolt tensile strength fuf = IF(3=1,400,830) = 830 MPa
Tensile stress area As = CHOOSE(4,84.3,157,245,353,561,817) = 353 mm²
Core area Ac (threads) = CHOOSE(4,76.2,144,225,324,519,759) = 324 mm²
Shank area Ao = CHOOSE(4,113,201,314,452,707,1018) = 452 mm²
Plate yield stress fy (AS/NZS 3678) = CHOOSE(1,IF(25<=8,280,IF(25<=12,260,250)),IF(25<=8,320,IF(25<=12,310,IF(25<=20,300,280))),IF(25<=12,360,IF(25<=20,350,340))) = 250 MPa
Plate tensile strength fu = CHOOSE(1,410,430,450) = 410 MPa
Σ 2 r² (two bolts per row) = 2*(290^2+210^2+0^2) = 2.564e+5 mm²
Top bolt tension M r1/Σ2r² = 120*1000*290/2.564e+5 = 135.73 kN
φNtf = 0.8*353*830/1000 = 234.39 kN
Plate thickness required √(2 T m/(φ fy p)) = SQRT(2*135.73*1000*40/(0.9*250*85)) = 23.827 mm
Number of bolts (tension rows + 2 shear bolts) = 2*(1+IF(210>0,1,0)+IF(0>0,1,0))+2 = 6
Shear per bolt (all bolts) = 90/6 = 15 kN
φVf (threads included) = 0.8*0.62*830*324/1000 = 133.38 kN
Flange force M/(d − tf) = 120*1000/(360-11.5) = 344.33 kN
Flange weld capacity (both sides of flange) = IF(1=1,0.8,0.6)*0.6*490*10/SQRT(2)*2*171/1000 = 568.79 kN
Bolt interaction (V/φVf)² + (N/φNtf)² = (15/133.38)^2+(135.73/234.39)^2 = 0.34795
Limit = 1 = 1

Related steel calculators

Bolted moment end plate (extended, 8.8/TB) — Extended end plate on a UB beam framing into a UC column flange. The flange force M*/(d − tf) goes to the…
Extended end plate (4-bolt unstiffened) — Bolt rows either side of the tension flange share the flange force; plate checked as a T-stub…
Bolted flange splice (cover plates) — Flange force from moment and axial share; outer cover plate tension yield/fracture and short-column…
Bolted web splice — Web carries the shear plus its share of moment (Iw/I); double web plates; bolt group polar analysis with…
Butt-welded splice (CP / IP) — Complete penetration butt weld at parent strength, or incomplete penetration treated as a fillet on the…
Portal knee: column web panel zone — Shear in the column web panel from the rafter moment; diagonal stiffener area required if the web is…

For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.