Preprocess Tutorial 1>WORKING BY LAYERS Preprocess Tutorial 1>CREATING A HOLE IN THE PART 


CREATING A PROFILE

In our case, the profile consists of various teeth. Begin by drawing one of these teeth, which will be copied later to obtain the entire profile.

Creating a size-55 auxiliary line

Footnote: The GiD Toolbox is a window containing the icons for the most frequently executed operations. For information on a particular tool, click on the corresponding icon with the right mouse button.

Footnote: The coordinates of a point may be entered on the command line either with a space or a comma between them. If the Z coordinate is not entered, it is considered 0 by default. After entering the numbers, press Return . Another option for entering a point is using the Coordinates Window , found in UtilitiesToolsCoordinates Window .

Footnote: Pressing the ESC key is equivalent to pressing the center mouse button.

Figure 2. Creating a straight line

NOTE : The Undo option, located in UtilitiesUndo , enables you to undo the most recent operations. When this option is selected, a window appears in which all the operations to be undone can be selected.

Dividing the auxiliary line near "point" (coordinates (40, 0) )

Figure 3. Division of the straight line near "point" (coordinates) (40, 0)

Creating a 3.8-radius circle around point (40, 0)

Footnote: In GiD the decimals are entered with a point, not a comma.

Figure 4. Creating a circle around a point (40, 0)

Rotating the circle -3 degrees around a point

  • Use the Move window, which is located in UtilitiesMove .

  • Within the Move menu and from among the Transformation possibilities, select Rotation . The type of entity to receive the rotation is a surface, so from the EntitiesType menu, choose Surfaces .

  • Enter -3 in the Angle box and check the Two dimensions box. (Provided we define positive rotation in the mathematical sense, which is counter-clockwise, -3 degrees equates to a clockwise rotation of 3 degrees.)

  • Enter the point (0, 0, 0) under First Point . This is the point that defines the center of rotation.

  • Click Select to select the surface that is to rotate, which in this case is that of the circle.

  • Press ESC (or Finish in the Move window ) to indicate that the selection of surfaces to rotate has been made, thus executing the rotation.

Figure 5. The Move window

Rotating the circle 36 degrees around a point and copying it.

  • Use the Copy window, located in UtilitiesCopy .

  • Repeat the rotation process explained in section 2.4, but this time with an angle of 36 degrees (see Figure 6).

Figure 6. Result of the rotations

NOTE : The Move and Copy operations differ only in that Copy creates new entities while Move displaces entities.

Rotating and copying the auxiliary lines

  • Use the Copy window, located in UtilitiesCopy (see Figure 9).
  • Repeat the rotating and copying process from section 2.5 for the two auxiliary lines. Select the option Lines from the Entities type menuand enter an angle of 36 degrees.
  • Select the lines to copy and rotate. Do this by clicking Select in the Copy window.
  • Press ESC to indicate that the process of selecting lines is finished, thus executing the task (see Figure 7).

Figure 7. Result of copying and rotating the line.

  • Rotate the line segment that goes from the origin to point (40, 0) by 33 degrees and copy it (see Figure 8).

Figure 8. Result of the rotations and copies

Figure 9. The Copy window

NOTE : In the Copy and Move windows, the option Pick may be used to select existing points with the mouse.

Intersecting lines

  • Choose the option GeometryEdit IntersectionLine-line.

  • Select the upper circle resulting from the 36-degree rotation executed in section 2.5.
  • Select the line resulting from the 33-degree rotation executed in section 2.6 (see Figure 10).
  • Press ESC to conclude the intersection of lines.
  • Create a line between point (55, 0) and the point generated by the intersection. To select the points, use the option Join Ctrl-a in the Contextual menu.
  • Choose the option GeometryEdit IntersectionLine-line in order to make another intersection between the lower circle and the line segment between point (40, 0) and point (55, 0) (see Figure 11).
  • Then continue selecting to make an intersection between the upper circle and the farthest segment of the line that was rotated 36 degrees (see Figure 12).

Figure 10. The two lines selected

Figure 11. Intersecting lines

Figure 12. Intersecting lines

Creating an arc tangential to two lines

Figure 13. The line segments to be selected

Translating the definitive lines to the "profile" layer

Figure 14. Lines to be selected

Deleting the "aux" layer

NOTE: When a layer is clicked Off , GiD reminds you of this. From this moment on, whatever is drawn does not appear on the screen since it is in the hidden layer.

NOTE: To cancel the deletion of elements after they have been selected, open the mouse menu, go to Contextual and choose Clear Selection .

NOTE: Elements forming part of higher level entities may not be deleted. For example, a point that defines a line may not be deleted.

NOTE: A layer containing information may not be deleted. First the contents must be deleted.

Rotating and obtaining the final profile

  • Make sure that the activated layer is the "profile" layer. (Use the option Layer To use. )
  • In the Copy window, select the line rotation (Rotation , Lines ).
  • Enter an angle of 36 degrees. Make sure that the center is point (0, 0, 0) and that you are working in two dimensions.
  • In the Multiple Copies box enter 9. This way, 9 copies will be made, thus obtaining the 10 teeth that form the profile of the model (9 copies and the original).
  • Click Select and select the profile. Press the ESC key or click Finish in the Copy window in order to conclude the operation. The result is shown in Figure 15.

Figure 15. The part resulting from this process

Creating a surface

Figure 16. Creating a surface starting from the contour

NOTE : To create a surface there must be a set of lines that define a closed contour.


 Preprocess Tutorial 1>WORKING BY LAYERS Preprocess Tutorial 1>CREATING A HOLE IN THE PART