Nominal Flexural Strength

The nominal flexural strength of a beam member

M_{n} = C_{b} [M_{p} - (M_{p} - 0.7 \cdot F_{y} \cdot S_{x}) (\frac{L_{b} - L_{p}}{L_{r} - L_{p}})]

C_b	Lateral-torsional buckling modification factor for non-uniform moment diagrams
M_p	Plastic flexural strength
F_y	Yield strength
S_x	Elastic section modulus taken about the x-axis
L_b	Distance between braces
L_p	Limiting laterally unbraced length for the limit state of yielding
L_r	Limiting laterally unbraced length for the limit state of inelastic lateral-torsional buckling

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