Free Tool · EN 1993-1-1 §6.2.5 / §6.2.6 / §6.2.8

Beam Moment & Shear Capacity Calculator

Calculate bending Mc,Rd (§6.2.5) and shear Vpl,Rd (§6.2.6) for rolled I-sections. Auto section classification (Table 5.2). Shear-moment interaction per §6.2.8 when VEd > 0.5·Vpl,Rd. IPE, HEA, HEB, HEM, UB, UC.

Mc,Rd §6.2.5 Vpl,Rd §6.2.6 §6.2.8 Interaction Class 1–4 IPE · HEA · HEB · HEM UB · UC S235 · S275 · S355 · S420 · S460 NL / DE / BE No sign-up
Beam Parameters

Enter to compute bending utilisation MEd / Mc,Rd

Enter to compute shear utilisation VEd / Vpl,Rd and check §6.2.8 interaction

Results
Section class 1
Wpl,y (mm³) 161,000
Wel,y (mm³) 128,600
fy (N/mm²) 355
ε = √(235/fy) 0.8136
Web c/t 39.24
Flange c/t 6.68
Mc,Rd §6.2.5 (kNm) 57.16 kNm
Vpl,Rd §6.2.6 (kN) 526.3 kN
Av,z shear area (mm²) 2568 mm²
η factor (NA) 1
Shear buckling h_w/t_w 39.2 / 58.6 — ✓

Cross-section diagram
b = h = y-y z-z
Web c/t = Limits: Class 1 ≤ , Class 2 ≤ , Class 3 ≤
Flange c/t = Limits: Class 1 ≤ , Class 2 ≤ , Class 3 ≤

Frequently asked questions

What is the difference between Class 1/2 and Class 3 sections?
Class 1 and 2 sections can develop a plastic hinge — the entire web yields in compression and the section rotates under load. Class 1 (ε ≤ 72ε) allows full plastic redistribution; Class 2 (ε ≤ 83ε) reaches plastic capacity but with limited rotation. Class 3 sections (ε ≤ 124ε) only reach the elastic yield stress at the extreme fibres — the web does not fully yield, so W_el,y is used and no plastic redistribution is permitted.
Why are Wpl,y and Wel,y different?
W_pl,y (plastic modulus) assumes the entire section yields — compression zone to half-depth, tension zone to half-depth. W_el,y (elastic modulus) uses the centroid axis — it integrates stress over the cross-section assuming stress = My/E at every fibre. For a symmetrical I-section about the major axis, Wpl ≈ 1.15 × Wel (roughly 15% higher for standard rolled sections).
How is section class determined in EN 1993-1-1?
Table 5.2 classifies sections based on c/t ratios. For the web (internal compression part): Class 1 if c/t ≤ 72ε, Class 2 if c/t ≤ 83ε, Class 3 if c/t ≤ 124ε, Class 4 otherwise — where ε = √(235/fy). For the flanges (outstand compression part): Class 1 if c/t ≤ 9ε, Class 2 if c/t ≤ 10ε, Class 3 if c/t ≤ 14ε, Class 4 otherwise. The governing class is the weaker of web and flange.
What does γM0 = 1.0 mean and is it the same in all national annexes?
γM0 is the partial factor for cross-section resistance. The EN default is 1.0, and the Dutch (NEN), German (DIN), and Belgian (NBN) national annexes all confirm γM0 = 1.0. This is the same value used for member buckling (γM1). The base EN value for buildings is 1.0; some older standards or specialized applications (e.g. bridges) used 1.1.
When should I use Class 4 effective properties?
Class 4 applies when any part of the cross-section exceeds the Class 3 limits (e.g. very slender webs in hot-rolled sections, thin-plate built-up members). For hot-rolled I-sections in grades S235–S460, Class 4 is rare — it typically only occurs in very deep IPE 600+ sections in low grades, or sections with very thick flanges relative to web. If your section is Class 4, you need to compute effective section properties per EN 1993-1-1 §5.5.2, which reduces the area and modulus due to local buckling. This tool does not compute effective properties for Class 4.