Nodal Supports

The dialog box for nodal supports corresponds to the dialog box for the calculation with 6 degrees of freedom, even when using the Torsional Warping (7 DOF) add-on. The RFEM manual describes the input of nodal supports in the chapter Nodal Supports. It is not possible to define a support for warping in this case.

Dialog Box "New Nodal Support"

Boundary Conditions for 6 Degrees of Freedom

By defining nodal supports, you specify the boundary conditions of the 6 degrees of freedom u_x, u_y, u_z, φ_x, φ_y, and φ_z at a node. In addition to defining spring values, nonlinearities are also possible.

In the case of a calculation with 7 degrees of freedom, nodal supports are assumed at the center of gravity of the cross-section. Depending on the location of the shear center of the cross-section used for the member, an additional torsional moment may result. In the case of a calculation with 6 degrees of freedom, the support for the transverse displacements u_y and u_z of the member is always located at the shear center.

Supports in Mass Center for Calculation with 7 Degrees of Freedom

Boundary Conditions for Warping

The warping at the member ends is assumed to be unrestricted by default. Use member transverse stiffeners to define warping restraints at the member ends. These can also be used to model a warping support.