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ÇYTHYE 2018 LTB — beam bending with unbraced length

Bending capacity including lateral-torsional buckling (LTB) for a given unbraced length Lb, per ÇYTHYE 2018 §8.2 / AISC 360 F2. Selects plastic / inelastic / elastic LTB regime automatically.

Doubly-symmetric I-sections under uniform moment (Cb=1.0 is conservative). For non-uniform moment enter Cb from AISC Table 3-10 or compute per AISC Commentary. Requires J and Cw from the section database (IPE: ArcelorMittal catalogue; HEA/HEB: thin-wall ~10-20% conservative for J).

Inputs

Steel grade

Profile series

Profile

Lb (unbraced length)mm

Cb (moment gradient)1.0 = uniform

Results

Lp [mm]—

Lr [mm]—

LTB regime—

Mn [kN·m]—

φb·Mn [kN·m]—

Citations

§8.2Lp=1.76ry√(E/Fy); Lr=1.95rts(E/0.7Fy)√(J/Sxh0+√(...)); Mn per regime. ÇYTHYE 2018 / AISC 360 F2.

VERIFYIPE500/S355 Lb=6000mm → elastic LTB, φMn=361 kNm (paper target 360 kNm, %0.3 fark).

Engine: steel-d.js v0.1.0 · DB: SECTIONS-EN10365.v1 ·

Preliminary calculation tool. Final design requires full regulatory text and a licensed engineer.