Avc = A − 2·b·tf + (tw + 2·r)·tf
= 11840 − 2×260×17.5 + (10 + 2×12)×17.5
= 3335 mm²
Vwp,Rd = 0.9 · fy,wc · Avc / (√3 · γM0)
= 0.9 × 355 × 3335 / (√3 × 1)
= 615.2 kN
Vwp,Ed = β · MEd / z
= 1 × 200 × 10³ / 400
= 500 kN
η = Vwp,Ed / Vwp,Rd = 500 / 615.2 = 0.813
→ PASS ✓ (81.3%)