Free Tool · EN 1994-1-1 §6.6

Shear Stud Connector Calculator

Design headed shear stud connectors for composite beams to EN 1994-1-1 §6.6. Computes stud design resistance PRd (shank + concrete failure), profiled deck reduction factor kt / kl (§6.6.4), minimum degree of shear connection ηmin (§6.6.1.2), required stud count and spacing.

P_Rd per stud
81.66 kN/stud PASS ✓
shank (§6.6.3 eq.6.18)
Calculation Steps
1. Stud resistance P_Rd (§6.6.3)
α = 1 (h_sc/d = 5.26) E_cm = 32837 MPa P_Rd,1 (shank) = 81.66 kN P_Rd,2 (concrete)= 83.13 kN P_Rd (solid) = 81.66 kN ← shank (§6.6.3 eq.6.18)
3. Min. shear connection η_min (§6.6.1.2)
η_min = 0.49 (§6.6.1.2 L=8m, fy=355 MPa)
4. Stud count and spacing
F_a = 2999.8 kN (steel) F_c = 2720 kN (slab) N_cf = 2720 kN (governs) n required (per shear span) = 17 n total = 34 calc. spacing s = 235 mm (min 5d=95 / max 480 mm) spacing OK: YES ✓
Beam Elevation — Stud Distribution
CONCRETE SLAB L = 8 m
5. Geometry checks (§6.6.5)
Check Value (mm) Limit (mm) Ref Result
h_sc ≥ 3d 100 57 §6.6.5.7 PASS ✓
Email calculation report
Enter your email to receive a formatted shear stud design report with clause references.
Auto-size shear studs on every composite beam in your drawing set
FrameAI Pro reads your IFC or PDF, extracts all composite beams and runs §6.6 checks — P_Rd, η, and stud count — in 90 seconds.
See Pro plans →
Related tools
Composite beam full design (M_pl,Rd + deflection) Composite beam design cheatsheet (EN 1994-1-1) Steel section properties Sample: composite office beam

FAQ — EN 1994-1-1 §6.6 Shear Studs

What is P_Rd for a 19mm headed shear stud in C30/37? +
For d=19mm, hsc=100mm, fu=450MPa, fck=30MPa (C30/37) on a solid slab with γV=1.25: P_Rd1 (shank) ≈ 81.5 kN, P_Rd2 (concrete) ≈ 73.1 kN. P_Rd = 73.1 kN governed by concrete. See §6.6.3 eq.6.18/6.19.
How is the deck reduction factor kt calculated? +
For ribs perpendicular to the beam: kt = (0.7/√nr)·(bo/hp)·((hsc/hp)−1) ≤ kt,max. kt,max = 0.85 for nr=1, hp≤60mm; 0.70 for nr=1, hp>60mm; 0.70 for nr=2, hp≤60mm; 0.55 for nr=2, hp>60mm (Table 6.2). For ribs parallel: kl = 0.6·(bo/hp)·((hsc/hp)−1) ≤ 1.0.
What is the minimum degree of shear connection? +
For simply supported beams with L≤25m: η_min = 1 − (355/fy)·(0.75 − 0.03L) ≥ 0.4 (EN 1994-1-1 §6.6.1.2 eq.6.13). For S355 and L=8m: η_min ≈ 0.511. For L>25m: η_min = 1.0.
Can I use 2 studs per rib? +
Yes. §6.6.5.3 permits up to 2 studs per rib for perpendicular deck ribs, but kt,max is reduced (0.70 for hp≤60mm; 0.55 for hp>60mm vs 0.85/0.70 for a single stud). For parallel ribs, EN 1994-1-1 does not limit studs per rib but kl applies to each stud.