Free Tool · EN 1993-1-1 §6.3.1 · Flexural Buckling · Steel Columns

Steel Column Flexural Buckling

Buckling resistance per EN 1993-1-1 §6.3.1. Select section and steel grade, set effective buckling lengths for both axes, get N_b,Rd with full step-by-step working and χ vs λ̄ curve.

Section

Material & Loads

Steel grade

γM1 — partial factor EN 1993-1-1 NA: 1.0 (most countries). NL/DE: 1.0.

NEd — design compression (kN) Leave 0 to skip utilization check.

Effective Lengths

Lcr = K × L. Enter directly or pick end conditions + system length.

System length L (m)

End conditions y-axis (K·L)

End conditions z-axis (K·L)

Lcr,y — effective length, major axis (m)

Lcr,z — effective length, minor axis (m)

χ vs λ̄ — Buckling Curves (EN 1993-1-1 Table 6.2)

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▸ Methodology — EN 1993-1-1:2005+A1:2014 §6.3.1

Critical load: Ncr = π²·E·I / Lcr² — where E = 210 000 MPa, I in cm⁴, Lcr in m.

Non-dimensional slenderness (§6.3.1.3 Eq. 6.50): λ̄ = √(A·fy / Ncr) for Class 1–3. For Class 4 use A_eff.

Buckling curve from Table 6.2 (depends on section type, h/b ratio, tf and fabrication). Imperfection factor α from Table 6.1: a0=0.13, a=0.21, b=0.34, c=0.49, d=0.76.

Reduction factor (Eq. 6.49): Φ = 0.5·[1 + α·(λ̄ − 0.2) + λ̄²], χ = min(1.0, 1/(Φ + √(Φ²−λ̄²)))

Buckling resistance: Nb,Rd = χ·A·fy / γM1

Governing axis: minimum of Nb,Rd,y and Nb,Rd,z.

References: EN 1993-1-1:2005+A1:2014 §6.3.1, Tables 6.1 and 6.2.