Modified design rule for Channel sections

The reduction factor for Lateral-Torsional Buckling of Channel sections is determined according to Ref.[22].

More specifically the calculation is done as follows:

This Modified design rule is applied only in case the following conditions are met:

• The section concerns a Channel section (Form Code 5)
• The General Case is used for LTB (Not the Rolled and Equivalent Welded Case)
• 15 <= L_ltb/h <= 40 (with L_ltb the LTB length and h the cross-section height)

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