MODEL CHECK

 

The functions in the MODEL CHECK menu are used to check the model to meet a specific forming simulation criteria.  The functions in this menu are illustrated in Figure 5.5.2.

Figure 5.5.2 Model Check

 

A detailed description of these functions is given in the following sections.

 

5.5.1.1 AUTO PLATE NORMAL

 

This function allows the user to make consistent normal direction for all elements of the selected part(s).

 

            Two options are used to select elements: ALL CURRENT PARTS and CURSOR PICK PART. eta/DYNAFORM will display the normal direction of the selected element.

 

            A eta/DYNAFORM QUESTION dialog box as illustrated in Figure 5.5.3 is displayed.

 

Figure 5.5.3 DYNAFORM Question dialog box

 

Select YES to accept the normal direction of all elements.

 

Select NO to reverse the normal direction of all elements.

 

NOTE: The user is recommended to select one part at a time.  Parts with branches may not have consistent normal direction.

 

5.5.1.2 BOUNDARY DISPLAY

 

This function allows the user to check the boundary of displayed part(s).  It is used to check the connectivity of elements.

 

eta/DYNAFORM highlights the free edges along a single surface.  For example, if three plate elements share a common edge, the common edge will be displayed as a boundary. An illustration is shown in Figure 5.5.4.

Figure 5.5.4 Surface Boundaries

 

NOTE:  The boundary will remain highlighted until the user hits the CLEAR icon from the ICON bar.

 

5.5.1.3 ASPECT RATIO CHECK

 

This function allows the user to check the aspect ratio of the displayed plate and solid elements. The aspect ratio is the ratio of the longest side to the shortest side of an element. In eta/DYNAFORM, the default aspect ratio is 8.0 to 1.0. The user may adjust the aspect ratio accordingly.

 

1.        The user may accept the default value of 8.0 or enter any positive real number. eta/DYNAFORM checks the elements with respect to aspect ratio. Elements that exceed the defined aspect ratio are highlighted. The following message will be printed in the message prompt window:

 

xxx ELEMENTS FAILED CHECK  ASPECT RATIO= xxx

      or

ALL ELEMENTS PASS CHECK

 

The number of failed elements and largest aspect ratio will be printed in the message prompt window.

 

2.        A eta/DYNAFORM QUESTION dialog box as illustrated in Figure 5.5.5 is displayed.

 

Figure 5.5.5 DYNAFORM Question dialog box

 

Select YES to display the CREATE PART dialog box.

 

Select NO to skip to the next function.

 

3.        eta/DYNAFORM prints the following message:

 

SELECT ELEMENT FOR ASPECT RATIO

 

The user can select any highlighted element to list its aspect ratio in the message prompt window.

 

5.5.1.4 INTERIOR ANGLE CHECK

 

This function allows the user to check the minimum values of the interior angles for shell and solid elements. eta/DYNAFORM checks and highlights any elements with interior angles that are less than the defined criteria. The user has an option to adjust the default criteria accordingly.

 

1.        Enter the interior angle in the displayed dialog box (DEFAULT = 1º). If the elements pass the interior angle check, eta/DYNAFORM prints the following message and goes back to the MODEL CHECK menu:

 

ALL ELEMENTS PASS CHECK!

 

If some elements does not pass the check, eta/DYNAFORM prints the following message with an option to create a new part.

 

xxxx ELEMENTS FAILED CHECK

 

2.        At same time, a eta/DYNAFORM QUESTION dialog box as illustrated in Figure 5.5.6 is displayed. If ADD TO NEW PART is selected, the CREATE PART dialog box is displayed to enable generation of new part.  If DELETE is selected, all failed elements are deleted.  The CANCEL option dismisses the operation.

 

Figure 5.5.6 DYNAFORM Question dialog box

 

5.5.1.5 OVERLAP ELEMENT

 

This function allows the user to check overlapping elements that share two or more edges.  If there are overlapping elements, the user can include these elements in a new part.

 

5.5.1.6 PLATE NORMAL

 

This function is used to draw a boundary line between elements with opposite normal directions.

If there are no opposing plate normals, eta/DYNAFORM prints the following message in message prompt window:

 

NORMAL CHECK COMPLETED, NORMAL IS CONSISTENT

 

5.5.1.7 ELEMENT SIZE

 

This function is used to check the minimum edge length of plate, solid, or beam elements. eta/DYNAFORM highlights all elements which does not pass the user-defined length criteria. The default is 1.0.  The user may change the default value.

     

            The user can include the failed elements in a new part.

 

            The user can delete all failed elements.

 

5.5.1.8 CHECK TAPER

 

This function allows the user to check the taper for quadrilateral elements.  Taper value is an amount of convergence.  A perfect element such as a rectangle has a taper value of zero.  The user can enter a value between 0 and 1 in the displayed dialog box (default is 0.5).

 

          The user can include the failed elements in a new part.

 

       The user can select any element to list its taper value in the message prompt window.

 

5.5.1.9 CHECK WARPAGE

 

This function allows the user to check the warpage angle of quadrilateral elements. The user has an option to split the quadrilateral elements into two triangular elements. All elements that fail the defined criteria may be added to a new part.

 

1.        Enter the warpage criteria (default is 5.0º).

 

2.       If elements do not pass the criteria, a eta/DYNAFORM QUESTION dialog box as illustrated in Figure 5.5.7 is displayed.

 

Figure 5.5.7 DYNAFORM Question dialog box

 

Select YES to replace warped quadrilaterals element with triangular elements.

 

Select NO to reject the operation.

 

3.        If the warped elements are not replaced, eta/DYNAFORM will ask the user to include the failed elements in the new part or continue to the next step.

 

4.        The user can select any element to list its warpage angle in the message prompt window.

 

5.5.1.10 FEATURE LINE

 

This function allows the user to check the angle between plate elements normal with user defined angle. Feature line is the edge of two adjacent plate elements with the angle between the plate normal equal or greater than the angle criteria.

 

1.        Enter angle criteria (default is 20º).

 

2.        Any feature line where the angle between the normal of adjacent elements is larger or equal to the angle criteria will be highlighted.  eta/DYNAFORM provides options for user to generate the plotel elements.

 

3.        If YES is selected, eta/DYNAFORM provides options for user to keep the element in a new part. The user creates new part using the CREATE PART dialog box.

 

5.5.1.11 DIE LOCK

 

This function is used to check if the die surface has any back draft wall angle. The program checks for an undercut of the elements of the die surface based on default angle criteria. The user is given an option to keep the failed elements in a new part.

 

5.5.1.12 TIME STEP

 

This function will display 10 blank elements that have the minimum time step, i.e., the 10 smallest blank elements. Both the time step and element ID number are printed in the message prompt window. 

 

5.5.1.13 SECTION CUT

 

There are several functions provided in the SECTION CUT dialog box as illustrated in Figure 5.5.8.

Figure 5.5.8 Section Cut dialog box

 

1.             CUT SECTION

This function allows the user to generate section lines that are intersections of the displayed finite element mesh with a set of parallel planes.

 

             Define a coordinate system by using the options provided in the LCS dialog box.

             Enter the starting location in W-COORDINATE for the first plane in the window, SECTION LOCATION, or click the STARTING SECTION button to select a node or point for the location.

 

             Enter the end location in W-COORDINATE for the last plane that is perpendicular to the W-axis, or click the END LOCATION button to select a node or point for the location.

             Enter the number of section planes along the W-axis in the window, NUMBER OF SECTIONS.

             eta/DYNAFORM will create a new part named SECTION which stores all section lines.

 

2.             LENGTH OF SECTION

This function allows the user to measure the arc length of a line. 

 

There are three options available in this function:

 

             CURSOR LOCATION

Select two points on a line. eta/DYNAFORM measures the arc length between two points and prints the following message in message prompt window:

 

LINE SEGMENT LENGTH IS: xxx

 

             LINE

          Select the desired line by cursor. The entire length of this section line will be measured and the length is printed in the message prompt window.

 

             REJECT LAST

Reject the last selection.

 

3.             MEASURE ANGLE

This function allows the user to measure the angle between two segments on a line.

 

             Select the desired line by cursor.

 

             Select two points on the line to define the linear regression line 1 in red. The user can reset the selection by using REJECT LAST POINT.

 

             Select another two points on the line to define the regression line 2 in red. The user can reset the selection by using REJECT LAST POINT.

 

             eta/DYNAFORM measures the angle between the two regression lines.  The result is printed in the message prompt window.

 

4.             SECTION ON/OFF

This function hides parts except for the part containing section lines. If toggled again, all hidden parts are displayed.