D.5.B.14.5 Lateral-Torsional Buckling Curves
In case of Cl: 6.3.2.2 of EC3, the Dutch National Annex tells to refer to appendix NB.NB to determine the critical elastic buckling moment Mcr.
The general formula for the critical elastic moment is
For the special case of a beam supported at either end subject to constant bending
moment is, the critical elastic moment can be calculated as:
where= | if h / tw > 75 and ɑ ≤ 5,000: | |||
= | ||||
= |
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= | For an I-section, this may be taken as: |
For the Dutch NA 2016, you must specify values for C1 and C2 using the C1 and C2 parameters in the design input mode. Otherwise, the default loading condition of a simply supported beam with uniform load is assumed (i.e., C1 = 1.13 and C2 = 0.45). Refer to D5.A.6 Design Parameters