Project
Ref
Engineer
Date
Service classMembers
Nail
Headside
Pointside (timber)
Timber–timber, single shear (nail)
Johansen Yield Modes
| Mode | EC5 ref | Raw (N) | +Rope (N) | Fv,Rk (N) |
|---|---|---|---|---|
| a | EC5 Table 8.2 (a) | 1672.5 | — | 1672.5 |
| b | EC5 Table 8.2 (b) | 2675.9 | — | 2675.9 |
| c | EC5 Table 8.2 (c) | 941.2 | — | 941.2 |
| d ◄ | EC5 Table 8.2 (d) | 749.1 | 80.8 | 830.0 |
| e | EC5 Table 8.2 (e) | 1043.1 | 80.8 | 1123.9 |
| f | EC5 Table 8.2 (f) | 859.2 | 80.8 | 940.1 |
EC5 Minimum Spacings — Table 8.2 (nail rules)
Timber (headside) — α = 0°
| Spacing parallel to grain (a1) | 33.5 mm |
| Spacing perpendicular to grain (a2) | 16.8 mm |
| Loaded end distance (a3,t) | 50.3 mm |
| Unloaded end distance (a3,c) | 33.5 mm |
| Loaded edge distance (a4,t) | 16.8 mm |
| Unloaded edge distance (a4,c) | 16.8 mm |
Timber (pointside) — α = 0°
| Spacing parallel to grain (a1) | 33.5 mm |
| Spacing perpendicular to grain (a2) | 16.8 mm |
| Loaded end distance (a3,t) | 50.3 mm |
| Unloaded end distance (a3,c) | 33.5 mm |
| Loaded edge distance (a4,t) | 16.8 mm |
| Unloaded edge distance (a4,c) | 16.8 mm |
Lateral Design Capacity
| Arrangement | Timber–timber, single shear (nail) |
| Length ℓ → embedded penetration tpen (= mode bearing length) | 65 → 40.0 mm |
| Governing mode | d |
| My,Rk (Eq 8.14, 0.30·fu·d^2.6) | 4172 N·mm |
| Fv,Rk per nail | 830.0 N |
| γM,connection | 1.30 |
Fv,Rd = kmod · Fv,Rk / γM — per EC5 Table 3.1 load-duration class:
| Load duration | kmod | Rd (N) | kN |
|---|---|---|---|
| Permanent | 0.6000 | 383 | 0.38 |
| Long-term | 0.7000 | 447 | 0.45 |
| Medium-term | 0.8000 | 511 | 0.51 |
| Short-term | 0.9000 | 575 | 0.57 |
| Instantaneous | 1.1000 | 702 | 0.70 |
Axial Capacity (Withdrawal) — EC5 §8.3.2 (Eq 8.24)
| Pointside withdrawal fax,k | 2.45 N/mm² |
| Headside pull-through fhead,k | 8.57 N/mm² |
| Pointside term fax,k·d·tpen | 328.3 N |
| Headside term fhead,k·dh² | 487.5 N |
| Penetration factor (§8.3.2(7)) | 0.985 |
| Fax,Rk = factor · min(…) [pointside governs] | 323.4 N |
Fax,Rd = kmod · Fax,Rk / γM — per EC5 Table 3.1 load-duration class:
| Load duration | kmod | Rd (N) | kN |
|---|---|---|---|
| Permanent † | 0.6000 | N/A | N/A |
| Long-term † | 0.7000 | N/A | N/A |
| Medium-term | 0.8000 | 199 | 0.20 |
| Short-term | 0.9000 | 224 | 0.22 |
| Instantaneous | 1.1000 | 274 | 0.27 |
† Smooth nails may not carry permanent or long-term axial loading (EC5 §8.3.2(1)P) — those rows are a CODE PROHIBITION, not a computation error. Use threaded nails for sustained withdrawal.
Assumptions & advisory notes
- Geometry: ℓ = 65 mm, headside 25 mm, pointside 47 mm → embedded penetration tpen = 40.0 mm (= pointside bearing length in the Johansen modes, EC5 Fig. 8.4).
- Nail rules throughout (d = 3.35 mm ≤ 8 mm, §8.3.1.1(5)-(6)): embedment Eq 8.15 (not predrilled), angle-independent (§8.3.1.1(3)). Johansen modes run on d.
- My,Rk = 4172 N·mm — Eq 8.14 (0.30·fu·d^2.6, round wire), fu = 600 N/mm².
- Rope effect (§8.2.2(2)) capped at 15% of the Johansen part (nailRound); basis Fax,Rk = withdrawal capacity 323 N.
- Axial withdrawal: Eq 8.24 (smooth) — min(fax,k·d·tpen ; fhead,k·dh²); pointside-penetration factor 0.985 (§8.3.2(7)).
- fax,k = 20×10⁻⁶·ρk² = 2.45 N/mm² (pointside ρk 350), fhead,k = 70×10⁻⁶·ρk² = 8.57 N/mm² (headside ρk 350).
- §8.3.2(1)P — smooth nails may NOT carry permanent or long-term axial load; those duration rows are barred (N/A) in the axial table.
- For species especially sensitive to splitting (fir, Douglas fir, spruce — §8.3.1.2(7)), the required un-predrilled thickness rises to Eq 8.19 = 46.9 mm (14d / (13d−30)ρk/200).
- Nail d = 3.35 mm (≤ 6 mm) in timber ρk ≤ 500 — predrilling optional; branch Eq 8.15/8.16 and the Table 8.2 spacing set. Predrill in splitting-prone timber (see minimum-thickness note).
Fv,Rk (char.)0.83 kN
Permanent0.38 kN
Long-term0.45 kN
Medium-term0.51 kN
Short-term0.57 kN
Instantaneous0.70 kN