With a nodal release, the model can be decoupled at a specific location. You can use it to model, for example, a beam lying loosely on top of another (see image Crossing Beams with Nodal Release). The degrees of freedom on the node are controlled by the 'Nodal Release Type' that describes the properties of the hinge.
Nodal releases result in double nodes belonging to different parts of the model. An invisible member is created between these nodes. The internal forces and moments are regulated as for a member with the start in the original node and the end in the decoupled node.
Nodal Release Type
The properties of the release are described by a hinge, which in principle corresponds to a member hinge. Select the release type in the list, or define a new type using the
button. The corresponding dialog box is described in the Nodal Release Types chapter.
Released Objects
Specify the numbers of the members, surfaces, and solids that are decoupled at the node. You can use the
button to define the objects graphically in the work window.
Release Generation
As mentioned above, RFEM creates a copy of the node. In the list, select whether to place the release (hinge) on the 'Original node' or the 'Released node'. The setting specifies with which part of the model the hinge is deforming, thus having an effect on the results.
Options
With the 'Deactivate release' check box you can cancel the decoupling on the node for certain analyses without deleting the nodal release itself.
Example
A cantilever lies loosely on a downstand beam. In the case of uplifting loads, the members are decoupled on the node if a nodal release type in the form of a shear release is available for the direction uZ with a nonlinear effect. In addition, the rotation about the X-axis is enabled, which also acts nonlinearly.
