Constraints Panel

Use the Constraints panel to place constraints or enforced displacements on a model. This is accomplished by assigning a degree of freedom (DOF) constraint to the node.

Location: Analysis page

Constraints are load config 3 and are displayed with a triangle that connects to the node, with the dof numbers that apply to the node beside the triangle.

While both subpanels share many common inputs, the settings you specify are not shared between them, for example, you can change the value for each degree of freedom on the Edit subpanel without changing the values already specified for the same DOF's on the Create subpanel.

Create Subpanel

Option Action
entity selector Select entities.

In any case, the constraints are applied to nodes; this selection simply determines how those nodes are selected. Geometric points select the nodes at which they exist. Comps select all of the nodes contained within the chosen component.

If you choose comps or sets, the constraints are drawn using a single indicator.

When nodes is selected, click the switch to change the selection mode.
nodes
Select individual nodes.


Figure 1. Example: Nodes Selection
faces
Select all of the nodes on 2D and 3D faces. If there are discontinuities on a 2D face, then only the nodes inbetween the discontinuities will be selected.


Figure 2. Example: Faces Selection
2D faces ext
Select all of the nodes on a 2D face that contain discontinuities.


Figure 3. Example: 2D Faces Ext Selection
loops
Select all of the nodes on continuous free edges that make a closed loop simultaneously, such as the perimeter of a hole.
Important: Only valid for SHELL elements.


Figure 4. Example: Loops Selection
free edges
Select all of the nodes on free edges of elements. If there are discontinuities on an edge, then only the nodes on the free edges inbetween the discontinuities will be selected.
Important: Only valid for SHELL elements.


Figure 5. Example: Free Edges Selection
free edges ext
Select all of the nodes on free edges of elements that contain discontinuities.
Important: Only valid for SHELL elements.


Figure 6. Example: Free Edges Ext Selection
edges
Select all of the nodes on free edges or shared edges (butt joints, L/corner joints, and T-joints) of elements. If there are discontinuities on an edge, then only the nodes on the edge inbetween the discontinuities will be selected.
Important: Only valid for SHELL elements.


Figure 7. Example: Edges Selection
edges ext
Select all of the nodes on free edges or shared edges (butt joints, L/corner joints, and T-joints) of elements that contain discontinuities.
Important: Only valid for SHELL elements.


Figure 8. Example: Edges Ext Selection
display
Indicate where in the model to draw the indicator.
Important: Only available when the entity selector is set to comps or sets.
relative size Specify the size, in model units, to display constraints relative to the model size.
label constraints Show text labels next to constraints in the modeling window.
constant value / curve Select whether the constraint should be a constant value or use curve-based values. If curve, choose the desired curve.
fixed Select whether the constraint should be fixed.
face angle / individual selection
face angle
Determines which of the selected support entities will have the panel entity (ex: load, boundary condition, vector, set definition, and so on) applied.
The face angle value is used to determine which faces will be selected based on the angle difference between the selected and adjacent face normals. If the angle between the normals of the faces is less than this face angle value the face is included. This process is similar for edge selection, except that the angle between edges is used instead of the angle between faces.
Important: Only available when the entity selector is set to nodes, and the selection mode is set to faces, 2d faces ext, free edges, free edges ext, edges, or edges ext.
individual selection
Select individual elements on a face or select individual free/shared edges of elements.
Important: Only available when the entity selector is set to nodes and the selection mode is set to faces, free edges, or edges.
edge angle
Split edges that belong to a given face. When the edge angle is 180 degrees, edges are the continuous boundaries of faces. For smaller values, these same boundary edges are split wherever the angle between segments exceeds the specified value. A segment is the edge of a single element.
Important: Only available when the entity selector is set to nodes and the selection mode is set to free edges, free edges ext, edges, or edges ext.
xscale Change the value to alter the curve’s X scale (for example, time).
dof1 - dof6 Select the degree of freedom that you wish to constrain, then enter a value for the constraint.
load types Select a load type.

The available types depend on the current solver interface selected.

Update Subpanel

Input Action
entity selector Select entities.

In any case, the constraints are applied to nodes; this selection simply determines how those nodes are selected. Geometric points select the nodes at which they exist. Comps select all of the nodes contained within the chosen component.

If you choose comps or sets, the constraints are drawn using a single indicator.

When nodes is selected, click the switch to change the selection mode.
nodes
Select individual nodes.


Figure 9. Example: Nodes Selection
faces
Select all of the nodes on 2D and 3D faces. If there are discontinuities on a 2D face, then only the nodes inbetween the discontinuities will be selected.


Figure 10. Example: Faces Selection
2D faces ext
Select all of the nodes on a 2D face that contain discontinuities.


Figure 11. Example: 2D Faces Ext Selection
loops
Select all of the nodes on continuous free edges that make a closed loop simultaneously, such as the perimeter of a hole.
Important: Only valid for SHELL elements.


Figure 12. Example: Loops Selection
free edges
Select all of the nodes on free edges of elements. If there are discontinuities on an edge, then only the nodes on the free edges inbetween the discontinuities will be selected.
Important: Only valid for SHELL elements.


Figure 13. Example: Free Edges Selection
free edges ext
Select all of the nodes on free edges of elements that contain discontinuities.
Important: Only valid for SHELL elements.


Figure 14. Example: Free Edges Ext Selection
edges
Select all of the nodes on free edges or shared edges (butt joints, L/corner joints, and T-joints) of elements. If there are discontinuities on an edge, then only the nodes on the edge inbetween the discontinuities will be selected.
Important: Only valid for SHELL elements.


Figure 15. Example: Edges Selection
edges ext
Select all of the nodes on free edges or shared edges (butt joints, L/corner joints, and T-joints) of elements that contain discontinuities.
Important: Only valid for SHELL elements.


Figure 16. Example: Edges Ext Selection
display
Indicate where in the model to draw the indicator.
Important: Only available when the entity selector is set to comps or sets.
relative size Specify the size, in model units, to display constraints relative to the model size.
label constraints Show text labels next to constraints in the modeling window.
constant value / curve Select whether the constraint should be a constant value or use curve-based values.

If curve, choose the desired curve.
xscale Change the value to alter the curve’s X scale (for example, time).
dof1 - dof6 Select the degree of freedom that you wish to constrain, then enter a value for the constraint.
load types Select a load type.

The available types depend on the current solver interface selected.