This function allows the user to
define a symmetrical die by defining a bilateral symmetry plane.
Three part geometry options are
available in the Symmetry dialog box.
NO SYMMETRY (Default)
This is the default option. All other
functions provided in the Symmetry dialog box are disabled.
SYMMETRY
The part is defined as symmetrical
(the part itself is usually symmetrical).
HALF SYMMETRY INPUT
Only one half of the part geometry is available. The function will
mirror the other half of the part about a symmetry plane to create a complete
part.
There are three types of symmetry
options available. There are described as the following:
XZ-PLANE
The symmetry plane is parallel to
the XZ-Plane of the Global Coordinate System. The user must select two points
to define the XZ-Plane. The first point is used to define the location of the
symmetry plane, while the second point is used to define direction of the axis of
symmetry.
YZ-PLANE
The symmetry plane is parallel to
the YZ-Plane of the Global Coordinate System. The user must select two points
to define the YZ-Plane. The first point is used to define the location of the
symmetry plane, while the second point is used to define direction of the axis of
symmetry.
TWO-XY-POINT
The symmetry plane is normal to
the XY-Plane of the Global Coordinate System. The user must select two points
to define the XY-Plane. The first point is used to define the location of the
symmetry plane, while the second point is used to define direction of the axis of
symmetry.
The user can enter the Shift value
and click on or
to move the symmetry axis. If the nodes at the
plane of symmetry are not collinear along the symmetry plane, the Align Nodes
function can be utilized to correct the problem. When the part is defined as Half Symmetry,
eta/DYNAFORM will activate the Align Nodes function The user can define the tolerance input field
to align the nodes along the line of symmetry. After clicking on this button,
the program will pop up an eta/DYNAFORM Question dialog box, as shown in Figure 7.1.40, and highlight the result from the operation. As
illustrated in Figure
7.1.41, the user can select Yes to accept the result or
select No to correct the inconsistency between some nodes on symmetry plane and
symmetry plane direction within the offset range via adding align nodes by
cursor. The user can also select Abort to redefine the offset range.
Figure 7.1.40 eta/DYNAFORM Question dialog box
Figure 7.1.41
Highlight nodes
If Half Symmetry Input is selected,
the Mirror Geometry button will be activated. This function allows the user to
select elements, which will be mirrored about the symmetry plane(s). The Reset
button is used to undo the mirror operation.
The steps needed to define a symmetrical die are
listed as follows:
1.
Read
in the symmetrical geometry, mesh it and assign it as Die part.
2.
Select
a geometry type, for example, Half Symmetry.
3.
Select
a symmetry type, for example, Two – X-Y - Points.
4.
Using the Select Point(s)
button to select two points to define the symmetry plane and the axis
direction.
Figure 7.1.42 Half Symmetry Part with XZ-Plane defined by selecting two points
5.
Click
on the Mirror Geometry button. The
mirror result is illustrated in Figure 7.1.43.
Figure 7.1.43 The Mirroring Result
Note: Define the part geometry as Symmetry or Half Symmetry Input, if user click other type of part geometry, the eta/DYNAFORM Question dialog box will pop up below.
Figure 7.1.44 eta/DYNAFORM Question dialog
box
Yes
Click the Yes button, the part will restore to the status before define as Symmetry or Half Symmetry Input, without saving the tipping operations, delete created boundary fill features, binder and addendum. For Half Symmetry Input geometry, it will delete mirrored half part same time.
No
Click the No button to exit the dialog box with no operation.