General description
By using a line release, it is possible to decouple the model along a line -- for example, if surfaces are loosely connected or if only compression forces can be transferred.
Note
First, you have to define a release with specific properties in a Line Release Type. Then you can assign them to members, surfaces, and solids that jointly use one line (see Chapter 4.26).
Axial/Shear Release or Spring ux / uy / uz
A release oriented longitudinally or transversely to the line direction is defined by selecting the corresponding displacement in the dialog box or in the table. With the properties of a Spring, you can also model flexible releases.
The directions of displacements x, y, and z refer to the line's axis system. Use the Display navigator or the shortcut menu of a line to display the line axes (see Figure 4.103).
You can also assign nonlinear properties to the releases.
Select the Nonlinearity from the list and define it with the 
button in the dialog box.
The input of nonlinear release properties is described in Chapter 4.14.
The Coupled diagram - permanent release option allows you to apply the failure criterion of a certain degree of freedom for the other directions as well:
If the transfer of an internal force is prevented, all other degrees of freedom are also solved.
You can find an example of this in the following article:
https://www.dlubal.com/en/support-and-learning/support/knowledge-base/001446
Moment Release or Spring φx
With a moment hinge about the longitudinal line axis x, you can release the rotation of the line (torsion) between objects.
Note
You can find an example of the definition of a line release in the following article:
https://www.dlubal.com/en/support-and-learning/support/knowledge-base/001110