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How to use the end plate connection calculator

A bolted moment connection by the component method: what each input means, how to read the joint resistance, and which component governs.

All guides Inputs Result Calc sheet Walk-through Mistakes

1. What the calculator does

The bolted end plate calculator checks a moment connection between a steel beam and a column: an end plate welded to the beam and bolted to the column flange, flush or extended above the beam. It uses the component method: it finds the tension resistance of each bolt row from the end plate, the bolts and the column flange and web, the compression at the bottom flange, the web panel shear and the bolt shear, and builds the moment and shear resistance of the joint from them.

The code route is the EN 1993-1-8 component method (clause 6.2), with the South African (SAISC / SANS) section tables. The badge says it runs the STATIX connection engine, with published-example checks.

End plate connection calculator header with the PASS badge — The header: PASS 73 %, governed by the bolt shear group.

2. The inputs, group by group

Input	What it means	Typical value
Beam and column	The beam and column sections from the tables, and the steel grade.	457×191×67 UB to 305×305×137 UC, S355
End plate	Extended or flush, width, depth and thickness.	extended, 200 × 555 × 20
Bolts	Size, grade, number of tension rows, row pitch and gauge.	M20 10.9, 2 tension rows, pitch 90, gauge 100
Actions (ULS)	Factored moment, shear and axial force at the joint.	M 150 kNm, V 120 kN, N 0
More inputs	The frame type for the stiffness classification and other options.	defaults

End plate inputs: beam, column, end plate, bolts and actions — The inputs. The actions are ULS design values at the column face.

3. How to read the result

The drawings show the elevation and the view on the plate to scale, with the bolt rows, the welds and the moment resistance M_j,Rd in the header.

End plate elevation and view on the plate — Elevation and view B–B: extended end plate 200 × 555 × 20, 3 rows of M20 10.9, M_j,Rd 346.6 kNm.

The joint resistance card lists the moment resistance, the shear resistance, the compression resistance, the web panel shear, the top-row tension, the critical row with its lever arm, the governing component and the utilisation. Compare M with M_j,Rd and V with V_j,Rd; the worse of the two (and the other components) sets the utilisation.

Joint resistance card for the end plate — Joint resistance: M_j,Rd 346.6 kNm, V_j,Rd 165 kN, F_c,Rd 938 kN, web panel 886 kN, top row 353 kN; governing component bolt shear group at 73 %.

The badge names the governing component; here the bolt shear group (120 kN against 165 kN), not the moment (150 against 346.6 kNm). More shear bolts below the tension rows, or bigger bolts, fix that. The stiffness and classification line says whether the joint is rigid, semi-rigid or pinned for the frame analysis. Anything the engine could not run shows as NOT CHECKED.

Design checks summary for the end plate — Design checks: EN 1993-1-8 · 33 pass.

Verification table against SCI P398 examples — Verification: published SCI P398 moment-resisting joint examples, 5 of 5 within tolerance.

4. Calc sheet and take-off

The result (pass / fail and utilisation) stays free for everyone. Every check with its clause, the calc sheet and the bending schedule are open to signed-in users. Sign in free: 3 designs a month (one calculator, open for 24 hours). Unlimited with a calculator pack.

The detail drawing sheet (PDF / DXF) is part of the paid plan. The connection take-off collects every connection of this type in the project, with the plate, bolts, welds and steel mass.

Connection take-off of all end plate connections — The connection take-off: end plate, bolts and welds, 18.6 kg for one connection.

5. A 2-minute walk-through

Open the calculator: a 457×191×67 UB to a 305×305×137 UC with an extended 20 mm end plate and M20 10.9 bolts, M 150 kNm and V 120 kN.
Read the badge: PASS 73 %, bolt shear group.
Raise M to 300 kNm and see which component governs next.
Change the plate to flush and see M_j,Rd drop.
Thin the plate to 15 mm and watch the tension rows change mode.

6. Common mistakes

Only the moment. The shear on the bolts below the tension rows often governs, as here.
A thick plate “to be safe”. A thick plate can move the failure to the bolts, which is brittle; the plate yielding first is the ductile mode.
Ignoring the column. The column flange and web in tension, compression and shear are components too; a light column may need stiffeners; read the column components in the joint resistance card.
A rigid frame with a semi-rigid joint. Check the classification against what the frame analysis assumed.

8. Learn more

Try it nowThe calculator opens with the walk-through inputs above. The result is free; sign in for the checks, calc sheet and schedule.
Open the end plate connection calculator

A guide to using the calculator, not a design. Check every value against the current code and your own project, and have the design checked and signed by a registered professional engineer.

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