Steel beam flexural strength (AISC 360-22 Chapter F)

Doubly symmetric rolled I-shape, strong-axis bending, compact section assumed for local buckling. Computes nominal moment for yielding (M_p) and lateral-torsional buckling per Section F1 (AISC 360-22), then the governing nominal strength and LRFD design strength with φ_b = 0.90.

Material

Yield stress F_y (ksi)

Modulus E (ksi)

Section properties

Plastic modulus Z_x (in³)

Elastic modulus S_x (in³)

r_y (in.)

r_ts (in.) From AISC shape tables (not equal to r_y).

h_o (in.) Distance between flange centroids.

J (in⁴)

I_y (in⁴)

C_w (in⁶)

Unbraced length

Unbraced length L_b (in.)

C_b

Assumes compact flanges and web, doubly symmetric I-shape, loads in the plane of the web, and C_b per your load pattern. Compare to AISC 360-22 Chapter F and the Manual for your section and loading. Structoo is not affiliated with AISC.

Steel beam flexural strength (AISC 360-22 Chapter F)

Summary

Yielding (Section F2.1)

Lateral-torsional buckling (Section F1)