BOUNDARY CONDITIONS

The functions of the BOUNDARY CONDITIONS MENU create and verify constraints and loads on finite element models. The functions in the BOUNDARY CONDITIONS MENU are shown in Figure 6.7.1.

                   

     

2

2

2

2

LOADING OPTIONS

The LOAD SET dialog window displays, see Figure 6.7.2.

                         

  

2

2

2

2

2

2

2

2

2

2

SHOW SPC ON

Toggles SPC (single point constraint) ON/OFF, see SPC OPTIONS.

1. CREATE FORCE on selected nodes.

  

2

2

2

2

       

DOF

Degree of freedom, the meaning of these numbers is as follows:

1 - X (Force will be applied in X direction)

2 - Y (Force will be applied in Y direction)

3 - Z (Force will be applied in Z direction)

4 - RX (Moment will be applied about X direction)

5 - RY (Moment will be applied about Y direction)

6 - RZ (Moment will be applied about Z direction)

LOAD CURVE ID

Load curve describes motion value versus time, see Section CREATE CURVE UTILITIES/LOAD CURVE/CREATE CURVE.

SCALE FACTOR

Load curve scale factor.

2. CREATE PRESSURE on selected elements.

 

  

2

2

2

2

LOAD CURVE ID

See CREATE FORCE.

SCALE FACTOR

See CREATE FORCE.

BIRTH TIME

Time imposed motion/loading is active.

The following three functions are used for both loading node force and element pressure.

DELETE

A DYNAFORM Question dialog window appears, see Figure 6.7.5.

         

2

2

      

Select YES to delete the last selected load set.

Select NO to reject the choice.

DEFINE

Add more nodes or elements to a selected load set.

REMOVE

Remove some selected nodes/elements from a load set.

SPC OPTION

This function allows the user to create and/or modify the SPC options. The SPC SET dialog window appears, see Figure 6.7.6.

                    

 

2

2

2

2

2

2

2

2

2

2

2

2

2

2

SHOW SPC ON

Toggles SPC ON/OFF to show the current SPC set.

SHOW FORCE ON

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

1. CREATE SPC SET

1. X-Translation

2. Y-Translation

3. Z-Translation

4. X-Rotation

5. Y-Rotation

6. Z-Rotation

7. All Transformation

The following menu (Figure 6.7.7) provides the ways to define one or several constraints.

 

      

2

2

2

2

2

2

2

2

2. DELETE SPC SET

         

2

2

2

3. DEFINE SPC

4. RELEASE SPC

Remove some nodes from the selected SPC set.

CLEAR SPC

Remove all nodes from a selected SPC set. A DYNAFORM Question window is displayed, see Figure 6.7.9.

     

          

2

2

Select YES to delete all SPC.

Select NO to reject the choice.

INITIAL VELOCITY

This function allows the user to define and assign linear or angular velocities to selected nodes. See Figure 6.7.10.

2

2

2

2

2

2

2

2

SHOW SPC ON

See SPC OPTION.

SHOW VELOCITY ON

Toggles defined velocity set ON/OFF.

DEFINE

Create velocity set.

           

   

2

2

2

2

2

2

REMOVE

Remove some defined nodes from selected velocity set.

CLEAR

Remove all nodes from the selected velocity set. A DYNAFORM Question window appears, see Figure 6.7.12.

             

  

2

2

LIST

There are two choices:

1. ALL NODE

All nodes with an initial velocity are highlighted with an arrow.

2. NODE

The selected initial velocities of nodes are listed in the prompt window.

RIGID BODY STOPPER

This function allows the user to define the rigid body stopper. The rigid body stopper provides a convenient way of controlling the motion of rigid tooling in metal forming. For a detailed description, refer to the LS-DYNA User's Manual. The options are shown in Figure 6.7.13.

                      

     

2

2

2

2

2

2

2

2

2

2

2

2

2

 

    

2

2