Material and cross-section, shared by every verification. Change the verification above and these stay as they are.
Checks a rectangular solid-timber or glulam bar in axial tension parallel to the grain at the ultimate limit state, to SIA 265:2021, on the net section left by the connection. Every step shows its formula and the clause it comes from.
You enter the member (wood type, strength class, load duration, service class, b, h), the design tensile strength ft,0,d from your copy of SIA 265 (clause 3.4.2.2, table 9, tabulated for ηt = ηw = 1.0), and the design tensile force Nd. For the section loss you choose one of three methods: an indicative coefficient for pre-design, a calculation from the connection, or the net area entered directly. For the calculation from the connection you enter the number of inset steel plates and the groove thickness, the fastener type, the number of fasteners in the 150 mm zone and their diameter dSD.
You get the gross, reduced and net areas, the conversion factors, the design resistance and stress, and the utilisation with a pass or fail, each with its clause. With the Basic plan, it prints as an A4 calculation note.
A glulam bar GL24h, b × h = 120 × 160 mm, in service class 1 under short to permanent actions, with ft,0,d = 12.0 N/mm² and a design tensile force of 150 kN, connected by one inset steel plate in a 6 mm groove and three 12 mm dowels or fitted bolts in the 150 mm zone. These are the module's own results for its worked example, computed when this page was built.
| Input | Value | Ref. |
|---|---|---|
| Wood type | Glulam | |
| Strength class | GL24h | |
| Load duration ηt | Short to permanent | § 2.2.6 |
| Service class ηw | 1 | § 3.2.1.3 t.4 |
| Section width b | 120 mm | |
| Section depth h | 160 mm | |
| Design tensile strength parallel to grain ft,0,d | 12.0 N/mm² | § 3.4.2.2 t.9 |
| Design tensile force Nd | 150 kN | |
| Section loss determined by | Computed from the connection | |
| Number of inset steel plates nslot | 1 | |
| Groove thickness tslot | 6 mm | |
| Fastener type | Dowel or fitted bolt | |
| Fasteners in the 150 mm zone n | 3 | § 6.1.1.8 |
| Fastener diameter dSD | 12 mm |
| Step | Value | Ref. |
|---|---|---|
| Gross section areaA = b · h | A = 19,200 mm² | |
| Loss from inset plate groovesAslot = nslot · tslot · h | Aslot = 960 mm² | |
| Width remaining for fastenersbnet = b − nslot · tslot | bnet = 114.0 mm | |
| Total section lossAred = nslot · tslot · h + n · [b · dSD] | Ared = 5,064 mm² | § 6.1.1.8 |
| Net section areaAnet = A − Ared | Anet = 14,136 mm² | § 6.1.1.8 |
| Load duration factor | ηt = 1.00 | § 2.2.6 |
| Moisture factor | ηw = 1.00 | § 3.2.1.3 t.4 |
| Design resistancefRd = ft,0,d · ηt · ηw | fRd = 12.000 N/mm² | § 2.2.2 (3) |
| Design stressσt,0,d = Nd / Anet | σt,0,d = 10.611 N/mm² | |
| Tension parallel to the grainσt,0,d ≤ fRd | η = 0.884 · Pass88 % of the capacity used | § 4.2.1.1 (6) |
Verified clause by clause against SIA 265:2021 and against independent calculations used on real projects, before release.
All fasteners within any 150 mm length along the member, as clause 6.1.1.8 requires. The grooves for inset steel plates are deducted as well as the fastener holes.
The indicative coefficient when sizing the member; the calculation from the connection once the connection is known. If the net area comes from elsewhere, enter it directly.
The full calculation is shown on screen, free and without an account. A print-ready A4 calculation note is part of the Basic plan.
Norm: SIA 265:2021 · Page updated: 21 October 2026