Member shear panels provide the option of modeling the lateral support of members or member sets provided by stiffening bracing or the roof cladding, thus considering the shear stiffness of these structural components in the lateral-torsional buckling analysis of the trusses. A member shear panel in y is taken into account when determining the critical lateral-torsional buckling moment or the critical load factor for lateral-torsional buckling if this is calculated using the internal eigenvalue solver. In this case, a constant translational spring is applied across the entire member set or individual members.
Definition Type
The list offers several types of member shear panels to select from (see the image Dialog Box “New Member Shear Panel”):
- Trapezoidal sheeting
- Bracing
- Trapezoidal sheeting and bracing
- Define S-prov
Define S-prov
Currently, the shear panel stiffness still has to be determined manually (see an example in the technical article on the right). The following information is required for this:
- Shear panel stiffness
- Beam length
The shear panel stiffness can be determined based on the member elastic foundation as follows:
The beam length is automatically taken from the member or member set. If you want to specify the beam length manually, deactivate the “Define length automatically” check box.
Assignment via Member Support
The member shear panel shall be assigned to a member or member set via a member support. To do this, use the graphical selection option by clicking the
button (see the image Assigning Member Support) or use the member support dialog box. In the “Nonlinearity / Fictitious Stiffnesses” list, select the Shear Panel in y or Shear Panel in z option.
In the “Shear Panel - y” or “Shear Panel - z” tab, you can assign the corresponding shear panel.
In the editing dialog box of the member shear panel, you can also assign the shear panel to a member support graphically using the
button. However, it is necessary to define a fictitious stiffness of the “Member Shear Panel” type for the member support.
Position of Shear Panel on Cross-Section
You can specify the position of the shear panel on the cross-section in the “Eccentricity” tab of the New Member Support dialog box.
The nine check boxes under “Reference” represent key points on the cross-section. The center point corresponds to the center of gravity, while the eight edge point correspond to the intersection points of the member axes y and z with the edges of a rectangle circumscribing the cross-section. In addition, the center of gravity and the shear center are available as reference points.
In the “Offset” input boxes, you can manually define the eccentricities ey and ez of the shear panel. The distances refer to the local member axes y and z. The shear panel is located at the cross-section based on the distance defined as the offset relative to the selected reference point.
