CREATING THE FIRST COMPONENT PART |
In this section the entire model, except the T junction, will be created. The model to be created is composed of two pipes forming a 60-degree angle. To start with, the first pipe will be created. This pipe will then be rotated to create the second pipe.
- Select the ok
layer and click on Layer To use
. From now on, all entities created will belong to the ok
layer.
- Choose the Line
option, located in Geometry->Create->Straight line.
- Enter the following points: (0, 11), (8, 11), (8, 31), (11, 31), (11, 11) and (15, 11). Press ESC
to indicate that the process of creating lines is finished.
Figure 8. Profile of one of the disks around the pipe
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- From the Copy
window, choose Lines
and Translation
. A translation defined by points (0, 11) and (15, 11) will be made. In the Multiple copies
option, enter 8 (the number of copies to be added to the original). Select the lines that have just been drawn.
Figure 9. The profile of the disks using Multiple copies
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- Choose Line
, located in Geometry->Create->Straight line.
Select the last point on the profile (at the right part of the profile) using the option Join Ctrl-a
,which is in the Contextual
menu in the mouse menu. Now choose the option No join Ctrl-a
. Enter point (200, 11). Press ESC
to finish the process of creating lines.
- Again, choose the Line
option and enter points (0, 9) and (200, 9). Press ESC
to conclude the process of creating lines (Figure 10).
Figure 10. Creating the lines of the profile
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Figure 11. Copy of the vertical line segment starting at the origin of coordinates
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- From the Copy
window, choose Lines
and Translation
. As the first and second points of the translation, enter the points indicated in Figure 11. Click Select
and select the vertical line segment starting at the origin of coordinates. Press ESC
.
- Choose Geometry->Edit->Intersection->Multiple lines.
Select the last two lines created and the vertical line segment coming down from the tangential center (see Figure 12). Press ESC
.
Figure 12. Selecting the lines to intersect
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- Choose Geometry->Delete->All Types
. (This tool may also be found in the GiD Toolbox.) Select the lines and points beyond the vertical that passes through the tangential center. Press ESC
. They will be deleted and the result should look like that shown in Figure 13.
Figure 13. Profile of the pipe and the auxiliary lines
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Creating the volume by revolution |
- Rotation of the profile will be carried out in two rotations of 180 degrees each. This way, the figure will be defined by a greater number of points.
- From the Copy
window, select Lines
and Rotation
. Enter an angle of 180 degrees and from the Do extrude
menu, select Surfaces
. The axis of rotation is that defined by the line that goes from point (0, 0) to point (200, 0). Enter these two points as the First Point
and Second Point
. Be sure to enter 1 in Multiple Copies
.
- Click Select.
For an improved view when selecting the profile, click Off
the “aux” layer. Press ESC
when the selection is finished. The result should be that illustrated in Figure 14.
Figure 14. Result of the first step in the rotation (180 degrees)
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- Repeat the process, this time entering an angle of –180 degrees.
- To return to the side view (elevation), choose Rotate->Plane XY
.
- Choose Render->Flat
from the mouse menu to visualize a more realistic version of the model. Return to the normal visualization with Render->Normal
. This option is more comfortable to work with.
Figure 15. The pipe with disks, created by rotating the profile.
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NOTE
: To select the profile once the first rotation has been performed, first select all the lines and then delete those that do not form the profile. Use the option Rotate->Trackball
from the mouse menu to rotate the model and make the process of selection easier.
Creating the union of the main pipes |
- Choose the Zoom In
option from the mouse menu. Magnify the right end of the model.
- Make sure the "aux" layer is visible.
- From the Copy
window, select Lines
and Rotation
. Enter an angle of 120 degrees and from the Do extrude
menu, select Surfaces
. Since the rotation may be done in 2D, choose the option Two Dimensions
. The center of the rotation is the tangential center.
Figure 16. The magnified right end of the model, and the lines to be selected
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- Click Select
and select the four lines that define the right end of the pipe (see Figure 16). Press ESC
when the selection is finished.
Figure 17. Result of the rotation
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- From the Copy
window, select Surfaces
and Rotation
. Enter an angle of -60 degrees. Since the rotation may be done in 2D, choose the Two Dimensions
option. The center of the rotation is the intersection of the axes, namely point (200, 0). Ensure the Do Extrude
menu is set to No
.
- Click Select
and select all the surfaces except those defining the elbow of the pipe. Press ESC
when the selection is finished.
Figure 18. Geometry of the two pipes and the auxiliary lines
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Creating the end of the pipe |
- From the Copy
window, select Surfaces
and Rotation
. Enter an angle of 180 degrees. Since the rotation may be done in 2D, choose the option Two Dimensions
. The center of rotation is the upper right point of the pipe elbow. Make sure the Do Extrude
menu is set to No
.
- Click Select
and select the surfaces that join the two pipe sections.
- In the Move
window, select Surfaces
and Translation
. The points defining the translation vector are circled in Figure 19.
Figure 19. The circled points define the translation vector.
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- Click Select
and select the surfaces to be moved. Press ESC.
The result should be as is shown in Figure 20.
Figure 20. The final position of the translated elbow.
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- Choose Geometry->Create->NURBS Surface->By contour
and select the four lines that define the opening of the pipe (Figure 21). Press ESC
.
- From the Files
menu, choose Save
in order to save the file. Enter a name for the file and click Save
.
Figure 21. Opening at the end of the pipe
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