solid model of the pulley

Solid Model Creation

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Introduction

This tutorial is the last of three basic tutorials devised to illustrate commom features in ANSYS. Each tutorial builds upon techniques covered in previous tutorials, it is therefore essential that you complete the tutorials in order.

The Solid Modelling Tutorial will introduce various techniques which can be used in ANSYS to create solid models. Filleting, extrusion/sweeping, copying, and working plane orientation will be covered in detail.

Two Solid Models will be created within this tutorial.

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Problem Description A

We will be creating a solid model of the pulley shown in the following figure.

Geometry Generation

We will create this model by first tracing out the cross section of the pulley and then sweeping this area about the y axis.

Creation of Cross Sectional Area

1. Create 3 RectanglesMain Menu > Preprocessor > (-Modeling-) Create > Rectangle > By 2 Corners
   BLC4, XCORNER, YCORNER, WIDTH, HEIGHTThe geometry of the rectangles:
   

   	Rectangle 1	Rectangle 2	Rectangle 3
   WP X (XCORNER)	2	3	8
   WP Y (YCORNER)	0	2	0
   WIDTH	1	5	0.5
   HEIGHT	5.5	1	5

   
   You should obtain the following:
   
   
2. Add the AreasMain Menu > Preprocessor > (-Modeling-) Operate > (-Boolean-) Add > Areas
   AADD, ALLANSYS will label the united area as AREA 4 and the previous three areas will be deleted.
   
3. Create the rounded edges using circlesPreprocessor > (-Modeling-) Create > (-Areas-) Circle > Solid circles
   CYL4,XCENTER,YCENTER,RADThe geometry of the circles:
   

   	Circle 1	Circle 2
   WP X (XCENTER)	3	8.5
   WP Y (YCENTER)	5.5	0.2
   RADIUS	0.5	0.2

   
   
4. Subtract the large circle from the basePreprocessor > Operate > Subtract > Areas
   ASBA,BASE,SUBTRACT
5. Copy the smaller circle for the rounded edges at the topPreprocessor > (-Modeling-) Copy > Areas
   • Click on the small circle and then on OK.
   • The following window will appear. It asks for the x,y and z offset of the copied area. Enter the y offset as 4.6 and then click OK.
     
   • Copy this new area now with an x offset of -0.5You should obtain the following
     
     
6. Add the smaller circles to the large area.Preprocessor > Operate > Add > Areas
   AADD,ALL
7. Fillet the inside edges of the top half of the areaPreprocessor > Create > (-Lines-) Line Fillet
   • Select the two lines shown below and click on OK.
     
   • The following window will appear prompting for the fillet radius. Enter 0.1
     
   • Follow the same procedure and create a fillet with the same radius between the following lines
     
8. Create the fillet areas
   • As shown below, zoom into the fillet radius and plot and number the lines.
     
     Preprocessor > (-Modeling-) Create > (-Areas-) Arbitrary > By Lines
     
   • Select the lines as shown below
     
   • Repeat for the other fillet
9. Add all the areas togetherPreprocessor > Operate > Add > Areas
   AADD,ALL
10. Plot the areas (Utility Menu > Plot - Areas)

Sweep the Cross Sectional Area

Now we need to sweep the area around a y axis at x=0 and z=0 to create the pulley.

1. Create two keypoints defining the y axisCreate keypoints at (0,0,0) and (0,5,0) and number them 1001 and 1002 respectively. (K,#,X,Y,Z)
2. By default the graphics will now show all keypoints. Plot Areas
3. Sweep the area about the y axisPreprocessor > (-Modeling-) Operate > Extrude > (-Areas-) About axis
   • You will first be prompted to select the areas to be swept so click on the area.
   • Then you will be asked to enter or pick two keypoints defining the axis.
   • Plot the Keypoints (Utility Menu > Plot > Keypoints. Then select the following two keypoints
     
   • The following window will appear prompting for sweeping angles. Click on OK.
     
     You should now see the following in the graphics screen.
     
     

Create Bolt Holes

1. Change the Working PlaneBy default, the working plane in ANSYS is located on the global Cartesian X-Y plane. However, for us to define the bolt holes, we need to use a different working plane. There are several ways to define a working plane, one of which is to define it by three keypoints.
   
   • Create the following Keypoints
     

     	X	Y	Z
     #2001	0	3	0
     #2002	1	3	0
     #2003	0	3	1

     
     
   • Switch the view to top view and plot only keypoints.
2. Align the Working Plane with the KeypointsUtility Menu > WorkPlane > Align WP with > Keypoints +
   • Select Keypoints 2001 then 2002 then 2003 IN THAT ORDER. The first keypoint (2001) defines the origin of the working plane coordinate system, the second keypoint (2002) defines the x-axis orientation, while the third (2003) defines the orientation of the working plane. The following warning will appear when selecting the keypoint at the origin as there are more than one in this location.
     
     Just click on 'Next' until the one selected is 2001.
     
   • Once you have selected the 3 keypoints and clicked 'OK' the WP symbol (green) should appear in the Graphics window. Another way to make sure the active WP has moves is:Utility Menu > WorkPlane > Show WP Status
     
     note the origin of the working plane. By default those values would be 0,0,0.
3. Create a Cylinder (solid cylinder) with x=5.5 y=0 r=0.5 depth=1 You should see the following in the graphics screen
   
   We will now copy this volume so that we repeat it every 45 degrees. Note that you must copy the cylinder before you use boolean operations to subtract it because you cannot copy an empty space.
   
4. We need to change active CS to cylindrical YUtility Menu > WorkPlane > Change Active CS to > Global Cylindrical Y
   This will allow us to copy radially about the Y axis
5. Create 8 bolt HolesPreprocessor > Copy > Volumes
   • Select the cylinder volume and click on OK. The following window will appear; fill in the blanks as shown,Youi should obtain the following model,
     
     
   • Subtract the cylinders from the pulley hub (Boolean operations) to create the boltholes. This will result in the following completed structure: