This window appears if at least one set of members is selected for design in the 1.1 General Data window.
The concept of this window is similar to the previous Window 1.12 Parameters - Members. Here, you can define the parameters for shear panel and rotational restraint for each set of members as described in Chapter 2.12.
If sets of members are analyzed according to the second-order analysis for flexural-torsional buckling with warping torsion (see Warping Torsion tab of Details dialog box), you can define precambers additionally in this window: The eigenshape has a strong impact on the warping analysis that is performed by taking into account seven degrees of freedom. Window 1.13 is extended accordingly for this input.
The warping analysis requires a license of the RF-/STEEL Warping Torsion module extension.
Based on the boundary conditions, RF-/STEEL EC3 determines the eigenshapes of the sets of members before the actual calculation is carried out. They will be considered accordingly for further analysis.
In column C, you enter the Initial Local Bow Imperfection relative to the length of the set of members. The most unfavorable value L/150 according to [1] Table 5.1 is preset. This value can be adjusted to the cross-section's buckling curve by taking into account the coefficient k for member imperfections according to [1] 5.3.4 (3).
The length of the entire set of members is preset as the reference length. As soon as the L Manually check box has been selected, the length can be user-defined in column E, for example to consider lateral supports.
Find more information about the application of bow imperfections in the RF-FE-LTB manual on our website.