The member support dialog box also corresponds to the dialog box of the calculation with 6 degrees of freedom when using the Torsional Warping (7 DOF) add-on. Entering member supports is described in Chapter Member Support of the RFEM manual. For the calculation with 7 degrees of freedom, the definition of notional stiffnesses from member shear panels and member rotational restraints is particularly relevant.
Activation of notional stiffnesses for static, stability, and modal analysis
Notional stiffnesses from the member shear panel and member rotational restraint have no effect on the static, stability, and modal analysis by default. You can activate the fictitious stiffnesses for this with the Structure Modification.
Assignment to Member or Member Set
Assign a member shear panel or a member rotational restraint to a member support in order to consider its stiffness in the calculation with 7 degrees of freedom I'm not able to. To do this, first select the notional stiffness 'Shear panel in y', 'Shear panel in z', or 'Rotational Restraint about x'.
In the "Shear Panel – y" or "Shear Panel – z" tab, you can then assign the shear panel you want. The member rotational restraint is selected in the same way in the 'Rotational Restraint' tab.
You can also add the member shear panel or the member rotational restraint to an Member Support graphically in the editing dialog box of the member shear panel or the member rotational restraint by using the button
button. However, the object of this type must already be assigned to the member support.
The member supports with the member shear panels or rotational restraints defined therein have to be assigned either to the members or to the superordinate member sets. Assign the member support by using the editing dialog box of the member or member set, the selection from the Member Support dialog box, or via the input table.
Definition of notional stiffnesses
Member shear panels and member rotational restraints can be entered by separate objects that are assigned to the member support. You can find a detailed description in the following chapters:
Location of member support on section
You can set the position of a member support on the cross-section in the 'Eccentricity' tab of the 'Member Support'.
Nine "Reference" check boxes symbolize distinctive locations on the cross-section. The point in the middle represents the centroid, and the eight edge points represent the intersections of the member axes y and z with the edge lines of a rectangle circumscribing the cross-section.
In addition to the nine check boxes, you can also use the center of gravity and the shear center as a reference point.
You can define the "offset" manually in the text boxes below. The distances are based on the position of the reference point and refer to the local member axes y and z.