TIPPING

 

In most stamping simulations, the global Z direction is selected as the stamping direction.  Some product design might not be compatible with the default setting of eta/DYNAFORM, therefore the tipping function is used to adjust the product to follow the stamping direction.  It allows the user to translate and/or rotate the part about a defined axis. The TIPPING dialog box is illustrated in Figure 6.1.29.

Figure 6.1.29 Tipping dialog box

 

Part(s) must be defined prior to performing tipping operation. The user can click on the SELECT PART button on the top of the menu to select part(s). All the selected part(s) will be locked as the tipping object.

 

6.1.10.1  TIPPING CENTER

 

This function is used to define location of tipping center.  

 

          DEFAULT - The default tipping center is set at center of mass. 

          USER DEFINE - The user selects a node, point or center coordinate as the tipping center using the INPUT COORDINATE dialog box as illustrated in Figure 6.1.30.

Figure 6.1.30 Selection of Tipping Center using INPUT COORDINATE dialog box

 

6.1.10.2  TIPPING WITH GEOMETRY (TOGGLE)

    

If the checkbox of this option is toggled on, eta/DYNAFORM will tip all the parts that are defined as DIE. All geometry in DIE including surfaces, lines and elements will be rotated and translated.

 

6.1.10.3  TIPPING WITH ALL PARTS (TOGGLE)

 

If the checkbox of this option is toggled on, eta/DYNAFORM will tip all the parts in the active database. All geometry including surfaces, lines and elements will be rotated and translated.

 

6.1.10.4  TIPPING CHECK

 

Upon completion of tipping operation, the user is recommended to apply the UNDERCUT and DRAW DEPTH functions to check the result.

 

·         DRAW DEPTH (toggle)

This function displays a contour plot showing the draw depth of part relative to the binder.  Different draw depths are displayed in graduated colors on the die.  Draw depth is estimated with reference to the first point of punch/die contact.  When the die/punch is closed, the first point on the blank to contact with the punch is locked.  The rest of the part will be stretched from this point spreading outward.

·         UNDERCUT (toggle)

This function displays a contour plot showing regions in the die with undercut. Red indicates severe under cut where the backdraft is less than 0º. Blue indicates a marginal area with a draw angle of approximately 1~3º.  Green indicates a safe region with a draw angle that is greater than 3º. The user can set the threshold for marginal and severe backdraft.

Figure 6.1.31 Tip Check Options

 

6.1.10.5  AUTO-TIPPING

 

This function automatically converts the die to stamping position by averaging all normal vectors of elements to minimize undercut and draw depth.

  

Before Tipping                              After Tipping

Figure 6.1.32 Tipping Check

 

NOTE: eta/DYNAFORM will automatically compute the tipping center. A default local coordinate system is created at the tip center with the UVW direction that is consistent with XYZ of the global coordinate system. The W axis is always set as the drawing direction. The functions on the tipping dialog box rotate the die so that the W axis is set as the drawing direction.

 

6.1.10.6  MANUAL TIPPING

 

In addition to the automatic tipping function described in Section 6.1.10.5, the user can manually tip the die about U, V, and W axes to a better draw direction. This function is very useful when auto-tipping does not provide a satisfactory tip result due to unbalanced mesh pattern or part shape. 

 

In manual tipping operation, the DIE can be rotated/translated about/along the U-, V-, or W-axis.  Using the U+/-, V+/-, W+/- buttons to perform the tipping operation according to the increment defined in the dialog box. The tipping check will be visible if the checkbox for UNDERCUT or DRAW DEPTH button is toggled on.        

 

          ROTATE

    Select ROTATE and key in any absolute rotation angle in the input field.  Click on the U+(-), V+(-), and W+(-) buttons that represent the rotation axis to rotate the model with defined angle about the selected axis.

 

          TRANSLATION

    If TRANSLATION option is selected, the U+(-), V+(-), W+(-) buttons represent translation direction.  The value in the input field of TRANSLATION is the incremental displacement along the selected axis.

 

6.1.10.7  UNDO AND RESET TIPPING OPERATION

 

The UNDO function will cancel the last performed tipping operation, while the RESET function will cancel all tipping operations.

 

 

6.1.10.8  DEFINED TIPPING

 

This function is used to record and restore the tipping operation. The ADD function is used to record the tipping result. The REMOVE function is used to remove one record.  The LOAD function is used to restore the tipping result to the selected record.

Figure 6.1.33 Defined Tipping field