University of Puerto Rico at Mayagüez Department of Mechanical Engineering Introduction to NX 6.0 Tutorial 4 Modified by (2011): Dr. Vijay K. Goyal and Dr. Ricky Valentin Associate Professors Juan Reines, Graduate Student Michael Jr. Cruz, Undergraduate Student Department of Mechanical Engineering University of Puerto Rico at Mayagüez

This model consist of four features. The base feature will be created in the XC-ZC plane. The second feature of the model is a cylindrical extrude feature. The third and fourth features use a rectangular sketch. The hole tool is used to create simple holes in the second, third and fourth features. Counter bore holes are use in the base feature. Problem Description

For better understanding of the dimensions from the solid part, the original schematic drawing is included in the figure below.

Go to Sketch, click on the drop down menu in the Sketch Plane rollout and choose Create Plane then click on the Full plane tool and choose from the drop down menu under Plane the YC-ZC plane, pick Absolute and click OK, on the Offset and Reference menu then pick a reference and click OK. Creating the Base Feature

Creating the First Feature  Invoke the Sketch environment using the YC-ZC plane and draw the sketch of the figure shown below. Use the Fillet feature for each of the four corners.

 Now we will extrude the sketch to create the 3D model of the shape. On the upper left corner select Extrude.  On the extrude window select “select curve” and select the sketch created  Change distance as required on drawing views (12mm) Creating the First Feature

Creating the Base Feature Click on the Line Icon on the top left of your screen. Place the mouse on the screen and it will ask you the coords of where you want your line to start, for this case XC = -43 and YC = 9. Then press enter. It will ask you the length of the line and angle, which is 86 and 0 respectively. Afterwards just keep on making lines by clicking the end of your last line, then entering the length and angle in the order shown on the table. Once you have a sketch like the one to the left click on Finish Sketch.

Creating the Second Feature  Now we will create the second feature, the cylinder.  Select extrude and select the base surface.

 Using circle draw the sketch for this feature as shown in the figure on right and select finish sketch. Creating the Second Feature

 Extrude window will be open. Change end distance as required (96mm), Make sure the extrude is in the correct direction if not select the reverse direction button.  Select the Unite option from the Boolean drop-down list to unit the two features.  Apply and then Ok.

To Reverse Direction button To unite features Creating the Second Feature

Creating the Third Feature Now we will create the third feature of this model Invoke the extrude tool and select the upper face on the cylinder as the sketching plane. Draw the sketch for this feature with the required dimensions as shown. Then Finish Sketch and open the Extrude.

Creating the Third Feature Change end distance to 76mm Select Unite from Boolean list. Make sure it is in the correct direction Apply and Ok.

Creating the Fourth Feature Now we will create fourth feature of this model Same that third, but in the right side of the cylinder as shown. Then Finish Sketch and Extrude window will open.

Change end distance to 58mm Select Unite from Boolean list. Make sure it is in the correct direction Apply and Ok. Creating the Fourth Feature

Creating the hole Feature Now we will create a Hole in the second feature. Choose Pre-NX5 Hole button from the Feature Operation toolbar. If not displaced, use the Command Finder The Hole dialog box is displayed Select the upper face of the second feature. Specify the hole properties.

Select Sketch Select the front face of the fourth feature Draw sketch using the given dimensions Creating the rectangular Cut

Select Extrude Enter depth 50 Select subtract

Creating Holes in the Third Feature Now we will create two Holes in the third feature. Invoke the sketch tool and select the plane side face on the feature as the sketching plane. Draw the sketch for this feature with the required dimensions as shown. Then Finish Sketch and open the Extrude window.

Creating Holes in the Third and Fourth feature Change end to Until Next. Select Subtract from Boolean list. Make sure it is in the correct direction! Apply and Ok.

Creating Holes in the Third and Fourth feature Now we will create two Holes in the fourth feature. Invoke the Sketch tool and select the plane side face on the feature as the sketching plane. Draw the sketch for this feature with the required dimensions as shown. Then Finish Sketch and open the Extrude window.

Creating Holes in the Third and Fourth feature Change end to Until Next. Select Subtract from Boolean list Make sure it is in the correct direction! Apply and Ok.

Next, we will create four holes over the base feature. Choose Pre-NX5 tool and select the top face of the feature as planar placement plane as shown. Select specific point on position dialog box. Pick the corresponding edges to locate the holes as shown. Creating Counter bore Holes in the Model

On Hole dialog box Change form to Counter bored. Specify required dimensions. Change depth limit to Trough Body. Select Subtract from Boolean list Make sure it is in the correct direction! Apply and Ok.

On the top left corner select the drop down of Start and select Advanced Simulation. On the Simulation Navigator right click on tutorial_1.prt Select New FEM and Simulation. Make sure Structural is selected on the Analysis Type section and hit ok. On the Solution Type you can select the constrain you want, on our case select SESTATIC 101 – Single Constraint and click ok. Creating the mesh

Use the 3D Tetrahedral Mesh feature as shown in figure on the right. This feature is available on the _prt_fem1 Session on the Simulation File View. On the Overall Element Size, choose 12. Click on the solid model and ok. You can see the imperfections on the model when a coarse mesh is created. This is clearly seen on the holes and the fillet on the model. Using Mesh Control feature, this imperfections are improved in order to obtain a more realistic and smooth model.

Use the Mesh Control feature as shown in figure on the right. Use Size on Face, on the Density Types section Select holes as shown on figure. On the Element Size section, use 2mm or less and click ok. Creating the mesh(cont).

Use Update Finite Element Model feature shown on the figure in order to regenerate the mesh. Now the element size on the orifices will become smaller and a better circular cross-sectional area can be appreciated… Creating the mesh(cont).

Use the Mesh Control feature as shown in figure on the right. Use Number on Edge, on the Density Types section Select the edges as shown on figure. On the Number of Elements section, use 20 elements and click ok. In order to see the number of elements before finishing the procedure, on the Preview section click on the icon shown in the figure.

Creating the mesh(cont). Use the Mesh Control feature as shown in figure on the right. Use Size on Face, on the Density Types section Select the edges(fillet) as shown on figure. On the Number of Elements section, use 2mm elements and click ok. In order to see the number of elements before finishing the procedure, on the Preview section click on the icon shown in the figure. **Remember to update the mesh after each mesh modification.

Creating the mesh(cont). Use the Mesh Control feature as shown in figure on the right. Use Size on Face, on the Density Types section Select the rectangular hole as shown on figure. On the Number of Elements section, use 2mm elements and click ok.

When the meshing procedure is done, you can appreciate the different element densities on the solid model. Creating the mesh(cont).

Creating material properties Click on the Material Properties icon shown on the figure. This feature is available on the _prt_fem1 Session on the Simulation File View. Click on the Library icon on the Materials window.(shown on the lower section of the figure) On the Search Criteria window, select metals on the Category section and click ok. Select Aluminum_6061.(you can select the material you like, but this tutorial is done with Lib Ref. #3.

Creating material properties Because a material from NX’s library was chosen, you can see default properties on the main window! Select the solid model to assign properties. Click ok.

Click on the Constraint Type icon shown. Select Fixed constraint. This feature is available on the _prt_sim1 Session on the Simulation File View. Select the surfaces shown in orange as done on the figure. The constraint nodes will appear as shown on the figure below. Creating Constraints

Creating Loads Click on the Load Type icon shown. Select Torque. This feature is available on the _prt_sim1 Session on the Simulation File View. Select the inner cylinder as shown in figure below. Select a magnitude 1000 N-mm and click ok.

Creating Solution Right-Click with the mouse on the Solution 1 from the Simulation Navigator. Click Solve. This feature is available on the _prt_sim1 Session on the Simulation File View. On the Solve window, click ok. When solver finishes, a Results icon will appear in the Simulation Navigator. Double- click and on the Post- Processing Navigator, expand Solution 1 as shown in the figure below.

Creating Solution Shown in the figure Von- Mises stresses. In order to play the animation, click the play icon circulated on the figure. If this icon is not visible, you can always use the Command Finder icon(binoculars)!

Saving the File Choose File > Save All from the menu bar to save the file. ** On the figure: Displacement- Nodal/Magnitude solution