MODEL CHECK

The functions in the MODEL CHECK menu validate the eta/DYNAFORM models to meet specified criteria. The options are shown in Figure 6.6.1.

                       

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

AUTO PLATE NORMAL

This function converts the normal direction of all elements in the selected part(s) to the specified direction.

                     

      

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Select YES and all selected element normals will be made consistent with referenced element normal.

Select NO and the reference element normal will be reversed. All selected element normals will be made consistent with the reference direction.

Note: We suggest selecting one part at a time. Parts that branch off or are separated do not always get adjusted properly.

BOUNDARY DISPLAY

This function checks the boundary of displayed part(s). It is used to check the proper corrections.

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, see the Figure 6.6.3.

Note: The boundary will remain highlighted until the user selects CLEAR.

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, but the user may adjust it as necessary.

1. Users may accept the default value of 8.0 or they may enter any real number that is a valid value for the aspect ratio. eta/DYNAFORM runs a check on the values for the aspect ratio. Any elements that exceed the desired aspect ratio are highlighted. The messages echoed in the prompt window are:

xxx ELEMENTS FAILED CHECK ASPECT RATIO= xxx

or

ALL ELEMENTS PASS CHECK

The number of failed elements and maximum aspect ratio will be displayed in the prompt window.

2. If there are failed elements, a DYNAFORM Question window appears, see Figure 6.6.4.

       

 

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Select YES and the CREATE PART dialog window appears.

Select NO to skip to the next function.

3. eta/DYNAFORM prompts:

SELECT ELEMENT FOR ASPECT RATIO

The user can select any displayed element and its value will be shown in the prompt window.

INTERIOR ANGLE CHECK

This function checks the minimum values of the interior angles for shell and solid elements. eta/DYNAFORM checks and highlights any interior angles that are less than the specified values. Users have the option to adjust the default values as necessary.

1. Enter interior angle in the next dialog window (DEFAULT = 1 DEGREES). If the elements pass the interior angle check, eta/DYNAFORM echoes the following message and returns the user to the MODEL CHECK menu:

ALL ELEMENTS PASS CHECK!

If some of the elements fail the model check, eta/DYNAFORM displays the following message with the option to create a new part.

xxxx ELEMENTS FAILED CHECK

2 .The user can create a new part to include these failed elements and can also delete these failed elements.

3. The user can select any element and its value will be given in the prompt window.

OVERLAP ELEMENT

This function allows the user to check for overlapping elements that share two or more sides.

If there are failed elements, the user can include these elements in a new part.

PLATE NORMAL

This function draws a boundary line between elements with opposite normal directions.

If there are not any opposing plate normals, eta/DYNAFORM prompts:

NORMAL CHECK COMPLETED, NORMAL IS CONSISTENT

ELEMENT SIZE

This function checks the minimum length of the edges of plate, solid, or beam elements. eta/DYNAFORM highlights all elements with an edge shorter than the user-defined length criteria. The default is 1.0 and the user can change the value.

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 next dialog window (default is 0.5).

CHECK WARPAGE

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

1. Enter warpage criteria (default is 5.0 degrees).

2. If there are any failed elements, a DYNAFORM Question appears. See Figure 6.6.5.

                      

   

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Select YES to replace warped quadrilateral with triangular element.

Select NO to reject.

3. If the warped elements are not replaced, eta/DYNAFORM prompts to include the failed elements in the new part or not.

4. The user can select any element and its value will be given in the prompt window.

FEATURE LINE

This function allows the user to check the angle between plate elements based on user specified angle criteria. The user can also generate beam elements at these locations.

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

2. Any feature line where the angle is larger or equal to the angle criteria will be highlighted. eta/DYNAFORM prompts to generate the plotel element.

3. If the user selects YES, eta/DYNAFORM will prompt to include the element in new part.

DIE LOCK

This function verifies that the construction of the die is correct, and that the size at any given point will not limit the punch's motion. It allows the user to check a tool's elements for undercut. The user has the option to add the failed elements to the new part.

TIME STEP

This function will display the 10 blank elements that have the minimum time step, that is to say, 10 smallest blank elements.

SECTION CUT

There are several functions in this menu, see Figure 6.6.6.

                       

     

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1. CUT SECTION

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

2. LENGTH OF SECTION

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

There are three options in this function:

  • CURSOR LOCATION

Select two points on a line. eta/DYNAFORM calculates the arc length between two points and prompts:

LINE SEGMENT LENGTH IS: xxx

  • LINE

Select desired line by cursor. The entire length of this section line will be calculated and given in the prompt window.

  • REJECT LAST

Reject last selection.

3. MEASURE ANGLE

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

4. SECTION ON/OFF

This function toggles all parts OFF except the section part. If toggled again, the parts that were initially displayed will come back ON.