NACA Duct Tutorial

NACA Duct Tutorial

Part 1 Part Design

1. Start CATIA and select the GSD workbenchStart>shape>Generative shape design

2. Change units to inchesTools>options>parameters and measure>units

3. Select a new partfile>new In the dialogue window select part and click ok. A new dialogue opens, enter NACA duct as the name for the tutorial, check create a geometric set, and select OK. Right click on the geometric set in the tree and click properties<feature properties to change the name to NACA duct.

CATIA V5 Aerospace Composite Design and Manufacturing by Ronald Sterkenburg

4. Select the xy plane in the tree or on the screen and click on the Sketch command. The screen will switch to the sketcher workbench. Create and dimension the sketch shown in the figure below.

5. Exit the Sketcher workbench by clicking on the Exit command. The screen switches back to the GSD workbench. Click on the screen so that the orange color of the profile changes to white.

6. Select the Extrude command on the Surfaces toolbar. Select the Sketch made in step 4 and enter information in the dialogue window as shown below. Right click in the direction box to select the z direction. Click OK.


7. Select the zx plane in the tree or on the screen and click on the Sketch command. The screen will switch to the Sketcher workbench. In the sketcher workbench

select the black triangle below the

Point command on the Profile toolbar which opens the point toolbar. Double click the Point by using coordinates command and enter the following coordinates: (1,-1), (0, 0), (-.49, 0.32), (-1.2, 0.65), (-5, 1.25), and (-7, 1.25)

8. Select the Spline command from the Profile toolbar and connect the first 5 points made in step 7 with a spline as shown in the figure below.


9. Select the Line command from the Profile toolbar and connect point 5 and point 6 with a line.

10. Exit the Sketcher workbench by clicking on the Exit command. The screen switches back to the GSD workbench. Click on the screen so that the orange color of the profile changes to white.

11. Select the Join command from the Operations toolbar. Click on the Spline (step 8) and Line (step 9) on the screen and click OK in the dialogue window.

12. Select the Extrude command in the Surfaces toolbar. Select the Join made in step 11 and enter the information in the dialogue window as shown below. Right click in the direction


box to select the y direction and check the Mirrored Extend button. Hide Sketch.2 and Join.1 in the tree.

13. Select the Trim command. It might be hidden behind the Split command. Click on the black triangle to show the trim command if necessary. When the trim command is selected a dialogue window will open and fill in the information as shown in the figure below. You might have to select the other side buttons to achieve the desired outcome.

14. Select the xy plane in the tree or on the screen and click on the Sketch command.

The screen will switch to the Sketcher workbench. In the Sketcher workbench select

the Rectangle command from the Profile toolbar and draw a rectangle around the part. Dimension as shown in the figure below.


15. Exit the sketcher workbench by clicking on the Exit command. The screen switches back to the GSD workbench. Click on the screen so that the orange color of the profile changes to white.

16. Select the Fill command on the Surfaces toolbar. Select the sketch profile you made in step 14 and click OK.

17. Select the Trim command. It might be hidden behind the Split command. Click on the black triangle to show the Trim command if necessary. When the trim command is selected a dialogue window will open and fill in the information as shown in the figure below. You might have to select the other side buttons to achieve the desired outcome. Click OK.


18. Select the black triangle below the Shape fillet

command in the Operations toolbar. This will open

the Edge fillet command . Select the Edge Fillet command and select the 2 edges as shown in the figure below. Enter the information in the dialogue box as shown.

19. Select the Plane command from the Wireframe toolbar. In the dialogue window enter the informtion as shown in the figure below.


20. Select the Split command from the Operations toolbar. In the dialogue window fill in the information as shown in the figure below. Click OK and hide Sketch.3 in the tree

21. Select the black triangle below the

Boundary command . This will open the Extracts toolbar. Select the

Multiple extract command . Set the Propagation type to Tangent continuity. Click on the edges shown in green on the part.


22. Select the Parallel curve command from the Wireframe toolbar and select the Multiple Extract from step 21. Fill in the information as shown in the figure below and select OK. Make sure that the parallel curve is on the outside of the Multiple Extract from step 21. (use Reverse Direction button)

23. Select the Split command form the Operations toolbar. Fill in the information in the dialogue box as shown in the figure below. Use the other side button if your part doesn’t resemble the figure below. Click OK.


24. Select the black triangle below the Shape fillet

command in the Operations toolbar. This will open the Fillets toolbar. Select the Edge Fillet command and select the edges as shown in the figure below. Enter the information in the dialogue box as shown in the figure below and click OK.

25. Hide Parallel.1 and Multiple extract.1 in the tree. Save your file as NACA duct.


Part 2 NACA Duct Tool Design

1. Start CATIA and select the GSD workbench Start>shape>Generative shape design.2. Open the NACA Duct CATPart file that was made in the part design chapter.3. Insert a new geometric set - insert>geometric set - and enter tool surface in the dialogue

window. Your tree should look like the figure below. The line under the tool surface indicates that this geometric set is in work (active folder). You can switch to another folder by right clicking on the folder and click on Define in work object.

4. Select the Boundary command from the Operations Toolbar. Select complete boundary and the part edge (Edgefillet.2)


5. Select the Multiple Extract command from the Operations toolbar select the highlighted edge as shown in the figure below. Change the propagation type to Tangent continuity. Click OK.

6. Select the Extrapolate command from the Operations toolbar and select the Multiple Extract created in step 5. Select the surface (EdgeFillet.2) as the extrapolated and change the continuity box to tangent. For length enter 4 in. See figure below. Click OK.

7. Select the xy plane and select the Sketcher command . Make a rectangle around the part and dimension it as in the figure.


8. Exit sketcher.

9. Click on the Split command in the Operations toolbar. Select the part surface as the element to cut and the sketch created in step 7 as the cutting element. Click OK.

10. Hide Sketch.4 in the tree.

11. Select the Multiple Extract command from the Operations toolbar select the highlighted edge as shown in the figure below. Change the propagation type to Tangent continuity. Click OK.

12. Click on the Extrude command in the Surfaces toolbar and select the multiple Extract created in step 11 as shown in the


figure below. Fill in the dialogue box as shown in the figure. Right click in the Direction window to select the x component and click OK.

13. Select the Join command from the Operations toolbar.In the dialogue window select Split.3 and Extrude.3 in the tree or on the screen and click OK.

14. Select the Plane command from the Wireframe toolbar in the dialogue window enter the information as shown in the figure below.


15. Select the plane created in step 14 and select the Sketcher command . Draw and dimension a line as shown in the figure below.

16. Exit Sketcher 17. Click on the Extrude command in the Surfaces toolbar and

select the line created in step 15 as shown in the figure below. Fill in the dialogue box as shown in the figure. Right click in the Direction window to select the z component and click OK.


18. Select the Trim command. It might be hidden behind the Split command. Click on the black triangle to show the trim command if necessary. When the trim command is selected a dialogue window will open and fill in the information as shown in the figure below. You might have to select the Other side buttons to achieve the desired outcome.

19. Select the Multiple Extract command from the Operations

toolbar select the highlighted edge as shown in the figure below. Change the propagation type to Tangent continuity. Click OK.


20. Click on the Extrude command in the Surfaces toolbar and select the edge shown in the figure below. Fill in the dialogue box as shown in the figure. Right click in the Direction window to select the x component and click OK.

21. Select the Join command from the Operations toolbar.In the dialogue window select Trim.3 and Extrude.5 in the tree or on the screen and click OK.


22. Select the Edge Fillet command from the Operations toolbar. Click on the edges shown in the figure below. (note: click on the center of the red lines which will highlight all edges at once)

23. A warning box might appear and click close. Your part should look like the figure below.

24. Select the Boundary command from the Operations Toolbar. Select Point continity and the part edge (Edgefillet.2) as shown in the figure below.


25. Click on the Extrude command in the Surfaces toolbar and select the Boundary created in step 24. Fill in the dialogue box as shown in the figure. Right click in the Direction window to select the z component and click OK

26. Select the Join command from the Operations toolbar.In the dialogue window select EdgeFillet.3 and Extrude.6 in the tree or on the screen and click OK.


27. Hide all Boundaries, sketches, lines, planes and Multiple Extracts in the tree.28. Save the file as NACA duct tool design.

Part 3 NACA Duct Ply Geometry

1. Start CATIA and select the GSD workbench Start>shape>Generative shape design.2. Open the NACA Duct Tool Design CATPart file that was made in the tool design chapter.3. Insert a new geometric set - insert>geometric set - and enter Ply Geometry in the dialogue

window. Your tree should like in the figure below. The line under the Ply Geometry indicates that this geometric set is in work (active folder). You can switch to another folder by right clicking on the folder and click on Define in work object.


4. The Heal command is used to correct small surface problems with the tool. Sometimes small gaps exists when the part is imported into CATIA, expecially if the source file is not a CATIA CATPart file. Select the Heal command from the Operations toolbar . It is most likely

hidden under the Join command . Click on the black triangle below the Join command which will open the Join-healing

toolbar . Click on the Heal command and select the tool surface and click OK.

5. Change the color of the tool to brown or other color of your choice. Click on the triangle next to the color selector and select the more color button in the bottom of the menu to select a color of your choice.


6. Right click on Boundary.1 in the tree (It is located in the Tool surface geometric set) and click on hide/show to show the boundary.

7. Select the Parallel Curve command from the Wireframe workbench and select the Boundary.1, which was created in step 6, from the tree or pick the white profile on the tool. Click on the tool surface and enter .25 in. as a constant and reverse the direction. Select Preview and make sure that the new curve is located on the outside of the Boundary.1. This new curve is the outside of the composite plies that will be placed on the tool surface. Composite part edges are typically made larger than the part dimensions so that the edges can be trimmed to achieve a high quality edge.


8. Hide Boundary.1 in the tree or on the screen.9. Select the Axis System command from the Tools toolbar and click on

the lower left vertex of the tool. Make sure that the z axis points up. Click OK.

10. Save your work as NACA Duct Ply Geometry


Part 4 Composites Catalog

Before the composite workbench can be used, a composite catalog needs to be set up or an existing catalog must be available. This tutorial will create a simple composite catalog which will be used to complete the tutorials of this book.

Composite materials are available in many different material types and styles. Carbon fiber and Fiberglass are the most common types of material used for Aerospace applications. These materials are available in both unidirectional and bi-directional styles. Unidirectional materials are often called Tape and Bi-directional materials are called Fabric. The type and style of the material greatly affect the strength and draping characteristics of the material. The composite designer must choose the best material for the application based on mechanical properties and the draping characteristics of the material. It is important to enter the correct material thickness of the material and draping (deformation) because CATIA is using this information for the design of composite plies. To learn more about composite materials consult: Structural Composites: Advance composites in aviation by Ronald Sterkenburg and Peng Hao Wang.

1. CATIA has a standard composites material catalog which can be accessed using the following link: Program Files>Dassault Systemes>B21>win_b64>startup>composites. (Note: Most companies have created their own customized catalogs.

2. Go to the link in step 1 and click on the CompositesCatalog and the catalog should look like the figure below.

3. Create a new catalog. Click on insert>new family

4. Select the New Material command in the Material Library toolbar.

.5. Double click on the New Material Icon on the screen. This will open the properties dialogue

window. Click on Feature Properties tab and change the Feature Name to Unidirectional Carbon.


6. Select the Composites tab and enter the information as shown in the figure below.

7. Repeat steps 4 thru 6 to create four more materials: Carbon Fabric, 8 harness Carbon Fabric, Fiberglass Fabric and Honeycomb. Enter the information as shown below (you don’t have to enter anything for honeycomb at this time):


8. Save the Material Catalogue as: Material Catalog


Part 5 NACA Duct Ply Design

1. Start CATIA.2. Open the NACA Duct Ply Geometry CATPart file that was created in the Ply Geometry

section. Switch to the Composite Design workbench: start>mechanical design>composite design or use your favorite menu.

3. Click on the Composites Parameters command. It is one of the few commands that can be selected at this time.

A dialogue window opens. Click on the Add materials tab (left figure) Click on the button with the three dots in it. A new dialogue window opens and select file. Now you can browse for your

Materials Catalogue which was made in the Materials Catalog tutorial.

4. Locate the Composite Catalog on your computer and double click on it. This opens a new dialogue window.

Click on Carbon Fabric and use the ctrl button on the keyboard to select 8 harness carbon fabric. This imports the material information to the Composite Parameters window.

Click on Default and select the remove button. Click on the 0 degree ply and change the color to

yellow. Click OK.


5. Select the End of Part (EOP) command from the Manufacturing toolbar.

EOP name – MEOP (Note: MEOP means Manufacturing End Of Part)

Surface – Click on Healing.1 in the tree or on the surface on the screen.

Contour – Click on Parallel.1 or click on the line indicated (red) in the figure below.Click OK. An EOP and MEOP are created in the tree.

6. Select the Ply Group command in the Plies toolbar. A dialogue window opens.

Surface – select Healing.1 in the tree or click on the surface.

Draping direction – Make sure that the red arrow points up. Click on Reverse Direction if it is pointing down.

Rosette – Click on the axis system. Check the box Lock plies draping direction.


Select OK. A plies group is created in the tree.

7. Select the Ply command from the Plies toolbar, and click on PliesGroup.1 created in step 6. This opens a dialogue window.

Select the Geometry tab and click on the MEOP in the tree.

Select the Attributes tabo Material – Fiberglass fabric o Direction – 0 degree

Click OK. A ply is created on the surface. You can only see the yellow outline.

8. Select the Producibility command from the

Flattening toolbar.

In the dialogue window enter the following information Selection – click on ply.1 in the tree Check Point Indication and click on the surface. A

strategy point appears: the long blue line indicates the zero degree direction and the red line indicates the 90 degree direction. The middle of the ply is a good


starting point to start the analysis. This point is used by the laminator and it is the first point of the ply that will be placed on the tool.

Set the Mesh Parameters to .1 in Propagation type – Symmetric Click Apply. Note that there are blue, yellow, and red areas on the screen.

o Blue: deformation of the ply is less than 15 degrees (this is good)o Yellow: deformation of the ply is more than 15 and less than 30 degrees.

(this might represent difficulty in laying up the ply without wrinkles)o Red: deformation of the ply is more than 30 degrees. (The red areas will

present problems during layup and a wrinkle will appear).

9. Click on other points on the tool surface and click Appy again. The producibility will change depending on where we chose the Point indication (strategy point). The figure below shows a major improvement over step 8. Typically, a point near the middle of tool works best, but try several locations to determine the best option.


10. Click OK in the Producibility window. The blue mesh will disappear and the producibility is added to the tree.

11. To remove the yellow areas of the mesh we will have to make darts in the ply or cut the ply into cut pieces. An alternative could be to select a material that will drape more than the plain weave carbon fiber fabric such as a 8 harness carbon fiber fabric.

12. Double click on Ply.1 in the tree and in the dialogue window click on the attributes tab and change the material to 8 harness carbon fiber. Click OK.

13. Double click on Producibility in the tree and select a strategy point on the top of the part as shown in the figure below. Click on Apply. This time the mesh has no yellow areas, which indicates that the 8 harness carbon fiber fabric will lay down without wrinkles.


14. Copy Sequence.1 in the tree and paste it in PliesGroup.1 three times, the three should look like the figure below.

15. Select the Interactive Ply Table command from the Analysis toolbar. Enter the following information in the table:

Select Ply (1) Unlock the plies (2) A warning pops up and

click OK Highlight all plies (3) Use shift command to

highlight all plies Enter Ply. (4) Click Rename (5) Click Apply (6)

16. Change the ply orientation of the plies in the interactive ply table. Highlight PLY.2 (1) Change the Direction to 45 (2) Highlight PLY.3 and change Direction to -45 Highlight PLY.4 and change Direction to 90 Click Apply and OK. (3)


17. Double click the Producibility of Ply.2 and check if all areas are blue. If not select another strategy point (point indication).

18. Repeat step 17 for Ply.3 and Ply.4.

19. Select the Plane command from the Wireframe toolbar and in the

dialogue window select: Plane type: Offset from plane Reference: xy plane Offset: 15in.


20. Make sure that the new plane goes up and use Reverse Direction button to change direction if the new plane goes down.

21. Insert a new Geometric Set: Insert>Geometric set. Name: Flattening points. Click OK.

22. Select the Point command from the Wireframe toolbar. In the dialogue window enter the following information:

Point type: on plane Plane: plane created in step 19 H and V coordinates (0, 0) Click Preview and OK


23. Switch to the Generative Shape Design workbench.

24. Select the Rectangular Pattern command from the Replication toolbar. Click on the point created in step 22. Select the plane created in step 19. Enter the information in the dialogue window as

shown below. o First direction tab: 4 instances and 15 inches spacing

Click OK.

25. Switch back to the Composite Design workbench.26. Check if all plies are in the show mode. If not right click on the ply and click Hide/show.

27. Select the Flattening command from the Flattening toolbar. In the dialogue window enter the following information:

Entities: Select the PliesGroup.1 in the tree Plane: Plane.3 created in step 19

Click on the multiselect icon which opens another window. Click on the points on the screen to assign location points for the plies. Click Apply


28. Select the Flatten optimization command from the Flattening toolbar.

In the dialogue window select PliesGroup.1 in the tree as the entity and click OK. The curves are smooth now which is desirable if the plies are exported to an Automated Ply Cutting table (Gerber table).

29. Select the Ply Data Export command and enter the information as shown in the dialogue window below. Export the file to a folder on your computer. Click OK.


30. Save your file as NACA Duct Ply Design.


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NACA Duct Tutorial

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