Release

Assigns a release of specified degrees of freedom to a selected beam in a structure.

When there are two or more adjoining beams, one of them should be fixed without a release at that beam end. Support already contains information about boundary conditions of adjoining beam.

Note: To ensure accurate simulation of releases, use a DSC Algorithm (Beam Releases) option in the Solver tab of the Frame Analysis Settings.

Access:

Ribbon: Frame Analysis tab Connections panel Release

Following release types are supported:

Fixed	Displacement and rotation are fixed for both directions.
Uplift none	Displacement and rotation are free in the compatible ("+") or opposite ("-") direction with respect to the axis of the beam local coordinate system. If your partial stiffness or elastic coefficients are 0, both directions are free without any value limitations. If you define any value for those coefficients, that limits the freeness of release in both directions - the release is free up to a defined limit.
Uplift+	Displacement and rotation are free in the compatible ("+") direction with respect to the axis of the beam local coordinate system. If your partial stiffness or elastic coefficients are 0, the compatible direction is free without any value limitations. If you define any value for those coefficients, that limits the freeness of release in the opposite ("-") direction. The release is free up to a defined limit.
Uplift-	Displacement and rotation are free in the opposite ("-") direction with respect to the axis of the beam local coordinate system. If your partial stiffness or elastic coefficients are 0, the compatible direction is free without any value limitations. If you define any value for those coefficients, that limits the freeness of release in the compatible ("+") direction. The release is free up to a defined limit.

Note: Releases are defined in the local beam coordinate system.

To define a new release, select beam, and define the released degrees of freedom at the start and the end of the beam element.

The beam start and end tabs allow you to specific the beam release behavior independently on each end of the beam. The Beam coordinate system is shown while editing, closer to the start end of the beam.

Also, when you define a release, symbols of degrees of freedom display at start and end node of the beam. Symbols of degrees of freedom display per your selections of displacement and rotation in the Release dialog box. “x” represents “fixed” type, “f” represents “uplift none” type, “f+” represents “uplift +” type, and “f-” represents the “uplift-“ type. For example: Symbol “xxxffx” displayed in the graphics window means that given start or end of the beam is connected with fixed displacement for X, Y, Z axes and with uplift none (free) for rotation along X and Y axis also with fixed rotation along Z axis.

The Elastic and Partial stiffness coefficients adjusts the method in which you can add stiffness can be added to a given degree of freedom.

	Beams	The command is active when the dialog box is displayed. Select a beam to apply the release. When you specify the beam, the OK and Apply buttons in the dialog box activate. Also, the beam coordinate system displays. It is positioned closer to start of the beam, the coordinate system is oriented towards the end of the beam.
	Elastic coefficient	Specify the exact value of displacement and rotation in N/mm. Note: The elastic coefficient (such as, the elastic coefficient for the UZ direction) can be defined only for the released direction (that is, for the direction UZ).
	Partial stiffness coefficient	The values range between: 0.0 (a released direction) and 1.0 (no release). The value of the element stiffness is multiplied by the value of the coefficient at the appropriate end.
	Displacement	Define the displacement degrees of freedom in the node: X axis, Y axis, Z axis. Use the drop-down list to select the constraint uplift for each direction (fixed, uplift none, uplift+, uplift-). If you select uplift none, uplift+, or uplift- type, you can define the elastic base coefficient K for each constraint.
	Rotation	Define the blocked rotation degrees of freedom in the node: X axis, Y axis, Z axis. Use the drop-down list to select the constraint uplift for each direction (fixed, uplift none, uplift+, uplift-). If you select uplift none, uplift+, or uplift- type, you can define the elastic base coefficient H for each constraint.
	OK	Create the release and close the dialog box.
	Cancel	Close the dialog box without creating the release.
	Apply	Create the release and keep the dialog box open. Click when you want to create multiple releases of the same type.

Start	End
X - axis: When selected, the displacement along the X axis in the beginning node of the beam element is released.	X - axis: When selected, the displacement along the X axis in the end node of the beam element is released.
Y - axis: When selected, the displacement along the Y axis in the beginning node of the beam element is released.	Y - axis: When selected, the displacement along the X axis in the end node of the beam element is released.
Z - axis: When selected, the displacement along the Z axis in the beginning node of the beam element is released.	Z - axis: When selected, the displacement along the X axis in the end node of the beam element is released.
X - axis: When selected, the rotation about the X axis in the beginning node of the beam element is released.	X - axis: When selected, the rotation about the X axis in the end node of the beam element is released.
Y - axis: When selected, the rotation about the Y axis in the beginning node of the beam element is released.	Y - axis: When selected, the rotation about the X axis in the end node of the beam element is released.
Z - axis: When selected, the rotation about the Z axis in the beginning node of the beam element is released.	Z - axis: When selected, the rotation about the X axis in the end node of the beam element is released.