This chapter's own worked example, built from the software's shipped default inputs, fails its net-section tension check — shown deliberately, not smoothed over, because a narrow effective plate width combined with a modest edge distance is a realistic and common way for a truss connection to under-perform its member capacity.
Every check above runs automatically inside the Structyze Truss Gusset Plate Connection module — this particular module is part of the full desktop catalogue rather than the free browser trial, since the trial only carries a curated flagship set. You can still try the free trial modules right now to see the same calculation style in action on RCC Beam, Column, Slab and a handful of others.
The Example We'll Use
- Bolted connection, 3 members (chord + diagonal) at the joint
- Gusset 10 mm, fy = 235 MPa, fu = 360 MPa
- Bolt M20, Grade 4.6, edge distance 35 mm, pitch 60 mm
- Member forces: top chord +150 kN, bottom chord −120 kN, diagonal +80 kN (4 bolts each)
Working Through It
Each member's own bolt group checks comfortably: governing capacity per bolt 47.05 kN, group capacity 188.2 kN — the top chord (150 kN) runs at utilisation 0.797, a genuine pass.
The governing member is the top chord. Net-section tension uses an effective width of just 70 mm (twice the edge distance); after deducting the 21 mm bolt hole, only 490 mm² of net area remains, giving a rupture capacity Nu,Rd ≈ 127.0 kN.
That 127.0 kN capacity is below the 150 kN demand — the gusset plate's own net-section rupture fails at utilisation 1.181, even though block tearing (utilisation 0.286) and every bolt group both carry real margin.
What Governs, and Why
The gusset plate's own net-section rupture is the single governing check for the whole joint, and it fails — a real, hand-verified result at BS EN 1993's own γM2 = 1.25 tension-fracture factor, not a contrived example. This is precisely the AS 4100/NZS 3404 comparison point this series makes elsewhere: the identical joint geometry under those codes' lighter 0.85 fracture factor and higher-strength default plate stays just under 1.0, while EC3's combination here genuinely fails.
Where Structyze Takes Over
Every check above runs automatically inside the Structyze Truss Gusset Plate Connection module — this particular module is part of the full desktop catalogue rather than the free browser trial, since the trial only carries a curated flagship set. You can still try the free trial modules right now to see the same calculation style in action on RCC Beam, Column, Slab and a handful of others.
For Truss Gusset Plate Connection and the rest of the full catalogue — 80+ components across RCC, Steel, Composite, Timber, Masonry and more, across 20+ design codes — buy the full Structyze desktop app or see everything it does on the Software page.
Quick FAQ
Why would the identical joint fail under EC3 but pass (barely) under AS 4100?
The combination of EC3's γM2 = 1.25 tension-fracture factor and this example's lower-strength S235 plate (fu = 360 MPa) pushes the net-section check over 1.0, while AS 4100's lighter 0.85 fracture factor and a higher-strength default plate elsewhere in this series keep the identical geometry just under the limit — a genuine, code-specific calibration difference, not an inconsistency in either calculation.
What's the practical fix for this specific joint?
Increasing the edge distance (widening the effective width beyond 70 mm), increasing the gusset thickness, or moving to two bolt rows would each restore margin — any change needs verifying against every other check, since a thicker or wider plate also shifts the block-tearing areas.
Final Thoughts
This gusset connection failing at the software's own shipped defaults is one of the most useful illustrations in this whole series of why the plate-tension check can never be treated as a formality once the bolt groups pass.