RFEM – Online Manual

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RFEM – Online Manual

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4.24 Nodal Releases

General description

With a nodal release, the model can be decoupled at a location. It is thus possible to consider, for example, that a beam lies only loosely on another one. You need to define a release with appropriate conditions for the nodal release. You can also consider nonlinear effects.

For nodal releases, RFEM generates nodes which belong to different parts of the model. An invisible member is generated between these nodes. The internal forces are the same as for a member with the start in the original node and end in the decoupled node.

Figure 4.200 New Nodal Release dialog box
Figure 4.201 Table 1.24 Nodal Releases
Node

The number of the relevant node can be entered, selected from the list, or defined graphically in the work window using .

Member Hinge

The hinge properties can be assigned by means of the member hinges, which are available in the list. Use the or button to open the New Member Hinge dialog box for entering another hinge type. This dialog box is described in Chapter 4.14.

Local Axis System

If you refer to a local axis system, you have to specify, which Member or Line is used as a reference. For hinges defined with regard to the global axis system, you cannot enter data in the text boxes.

Released Objects

The released Members, Surfaces, and Solids can be directly entered or graphically selected in the work window with .

Release Location

As already mentioned, RFEM creates a copy of the node. You can define whether the member end release should be placed at the Original node or at the Released node. This definition should not affect the results.

Example: Beam crossing with lifting forces

A cantilever lies loosely on a downstand beam. For lifting loads, the node is released if a shear force release in direction uz with nonlinear action is defined.

Figure 4.202 Deformation with hinge definition