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Flexural buckling of a column

Buckling resistance of a pinned HE 200 B column about its weak axis with buckling curve c. Reference: EN 1993-1-1 6.3.1, Table 6.1, Table 6.2.

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# Material
f_y := 355 MPa
gamma_M0 := 1.0
gamma_M1 := 1.0
E_s := 210 GPa
epsilon := sqrt(235 MPa/f_y) =

# Section HE 200 B (check against your tables)
A_g := 7808 mm^2
i_z := 50.7 mm
L_cr := 4.0 m

# Slenderness about z-z
lambda_1 := pi*sqrt(E_s/f_y) =
lambda_z := L_cr/(i_z*lambda_1) =
# Rolled H-section, h/b <= 1.2, t_f <= 100 mm, buckling about z-z: curve c.
alpha := 0.49
Phi := 0.5*(1 + alpha*(lambda_z - 0.2) + lambda_z^2) =
chi := min(1/(Phi + sqrt(Phi^2 - lambda_z^2)), 1) =

# Resistance
N_b.Rd := chi*A_g*f_y/gamma_M1 = kN
N_Ed := 1200 kN
N_Ed <= N_b.Rd =

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