CONSTRAINTS

  

This function allows the user to create and/or modify the constraint options. The CONTSTRAINTS dialog window appears as in Figure 5.7.6.

 

Figure 5.7.6 Constraints Options

SHOW CONSTRAINT

Toggle SHOW CONSTRAINT to show the current Constraint set.

 

SHOW FORCE

Toggle defined force ON/OFF to show the current load force.

ADVANCED OPTIONS

Toggle access to the advanced options for constraint definition.

 

1.          CREATE CONSTRAINT SET

 

l       Select a constraint type.  There are six degree of freedom in LS-DYNA:

 

1.     X-Translation

2.     Y-Translation

3.     Z-Translation

4.     X-Rotation

5.     Y-Rotation

6.     Z-Rotation

 

The following menu (Figure 5.7.7) provides the basic and advanced ways to define constraints.

     

 

a) Basic                                           b) Advanced

Figure 5.7.7 Constraint types

 

l       Select CREATE.

 

l       Enter the Constraint Set ID Number in the next window.

 

l       Select nodes to constrain.

 

2.         DELETE CONSTRAINT SET

 

l       Select a constraint set from the list.

 

l       Select DELETE.

 

l       Confirm the deletion in the DYNAFORM QUESTION window (Figure 5.7.8).

 

Figure 5.7.8 DYNAFORM Question Window

 

3.         DEFINE CONSTRAINT

 

l       Select a set from the list.

 

l       Select a type.

 

l       Select DEFINE.

 

l      Select nodes.  More nodes with the selected degree of freedom will be added to

the highlighted constraint set.

 

4.      RELEASE CONSTRAINT

Remove some nodes from the selected constraint set.

 

1.      CLEAR CONSTRAINT

Remove all nodes from a selected constraint set.  A DYNAFORM QUESTION window is displayed as in Figure 5.7.9.

 

 

Figure 5.7.9 DYNAFORM Question Window

 

Select YES to delete all constraints.

                                                                

Select NO to reject the choice.