Thursday 28 October 2010

Transient Thermal Conduction Example

Thermal - Mixed Boundary Example

Transient Analysis of a Cantilever Beam

Simple Conduction Example

Harmonic Analysis of a Cantilever Beam

NonLinear Materials

Modal Analysis of a Cantilever Beam

Buckling

Graphical Solution Tracking

Application of Distributed Loads

NonLinear Analysis of a Cantilever Beam

Effect of Self Weight on a Cantilever Beam

Monday 25 October 2010

Common catia or unigraphics interview question

What are the options available in exploded option?

How can you move the text along with view?

By giving the associatively in Edit View.

What is the different mating conditions?

What are the options available in Assembly edit?

What is the included angle in Hexagon?

What are Constraints?

What are the different options available in Transform?

What are the Translators?

What is the difference between import view and orthographic view?

What is Cloning Assembly?

What is Auxiliary View ?

What is Simplify?

What is Suppress?

What is Blank?

What is Delete?

What do you mean by Sweep along the guide?

What is Swept?

What is the Difference between part list and part family?

What is Tube?

What is the Difference between Ruled surface and Through curves?

What is the difference between absolute co-ordinate system and incremental co-ordinate system?

What is the difference between by by poles and through points in Spline?

What is the difference between Extract in curves and Extract in features?

What is Snap angle?

What are Basic curves?

What is ASCII?

What is Assembly?

What is Geometric Constraint?

What is Combine Curve Projection?

What is GPM and MDFG?

What is Wrap/Unwrap?

What is WCS?

What is MCS?

What are Translators?

What is the Kernel for UG/CATIA?

What is Top down assembly?

What is Bottom up Assembly?

What is Hybrid molding?

What is Grip?

What are Silhouettes curves?

What is angle for Isometric view in UG/CATIA?

What is angle for Trimetric view in UG/CATIA?

What are the different sheet sizes, Sheet Size, Trimmed Size and Untrimmed Size

What is the Difference between soft blend and face blend?

We have to give the radius in Face Blend, Yes or No?

Define the parameter Rho?

Define Feature?

Define Form Feature?

What is Quilt?

What do you mean by Sew?

What do you mean by Degrees of Spline?


Why should you use cubic splines [Low degree curves 3]?

What are the characteristics of high degree curves?

What are Defining points in Spline?

What are Knot Points in Spline?

What are Isocline Curves?

What are Extract Curve?

What is Sheet body?

What is Solid Body?

What is a Spline?

What is Template Part?

What are Part Families?

What is the use of Animate Constraint.

What is the use of Guide Curve?

Can you add Add objects to sketch?

What is Snap angle?

What is the use of Datum Planes?

What are Selection Sets?

List the different types of Geometric Constraints?

List the different types of Dimensional Constraints?

What is post processor?

What is a Instance?

What are Boolean options?

What is the use of Section command?

What are the different Image File Translators?

What are different 2d Translators?

What are different types of Positioning Dimension types?

Explain CLS, APT, PTP, MDFG, MDFA.

Sunday 3 October 2010

CAMWorks for UG-NX

Application of Distributed Loads



Introduction

This tutorial was completed using ANSYS 7.0. The purpose of this tutorial is to explain how to apply distributed loads and use element tables to extract data. Please note that this material was also covered in the 'Bicycle Space Frame' tutorial under 'Basic Tutorials'.
A distributed load of 1000 N/m (1 N/mm) will be applied to a solid steel beam with a rectangular cross section as shown in the figure below. The cross-section of the beam is 10mm x 10mm while the modulus of elasticity of the steel is 200GPa.

Preprocessing: Defining the Problem

  1. Open preprocessor menu/PREP7
  2. Give example a TitleUtility Menu > File > Change Title ...
    /title, Distributed Loading

  3. Create KeypointsPreprocessor > Modeling > Create > Keypoints > In Active CS
    K,#,x,yWe are going to define 2 keypoints (the beam vertices) for this structure as given in the following table:
    KeypointCoordinates (x,y)
    1(0,0)
    2(1000,0)


  4. Define LinesPreprocessor > Modeling > Create > Lines > Lines > Straight Line
    L,K#,K#Create a line between Keypoint 1 and Keypoint 2.

  5. Define Element Types
  6. Preprocessor > Element Type > Add/Edit/Delete...For this problem we will use the BEAM3 element. This element has 3 degrees of freedom (translation along the X and Y axis's, and rotation about the Z axis). With only 3 degrees of freedom, the BEAM3 element can only be used in 2D analysis.
  7. Define Real Constants
  8. Preprocessor > Real Constants... > Add...In the 'Real Constants for BEAM3' window, enter the following geometric properties:
    1. Cross-sectional area AREA: 100
    2. Area Moment of Inertia IZZ: 833.333
    3. Total beam height HEIGHT: 10
    This defines an element with a solid rectangular cross section 10mm x 10mm.
  9. Define Element Material PropertiesPreprocessor > Material Props > Material Models > Structural > Linear > Elastic > IsotropicIn the window that appears, enter the following geometric properties for steel:
    1. Young's modulus EX: 200000
    2. Poisson's Ratio PRXY: 0.3

  10. Define Mesh SizePreprocessor > Meshing > Size Cntrls > ManualSize > Lines > All Lines...For this example we will use an element length of 100mm.
  11. Mesh the framePreprocessor > Meshing > Mesh > Lines > click 'Pick All'
  12. Plot ElementsUtility Menu > Plot > ElementsYou may also wish to turn on element numbering and turn off keypoint numbering
    Utility Menu > PlotCtrls > Numbering ...

Solution Phase: Assigning Loads and Solving

  1. Define Analysis Type
  2. Solution > Analysis Type > New Analysis > StaticANTYPE,0
  3. Apply Constraints
  4. Solution > Define Loads > Apply > Structural > Displacement > On KeypointsPin Keypoint 1 (ie UX and UY constrained) and fix Keypoint 2 in the y direction (UY constrained).
  5. Apply Loads
  6. We will apply a distributed load, of 1000 N/m or 1 N/mm, over the entire length of the beam.
    • Select Solution > Define Loads > Apply > Structural > Pressure > On Beams
    • Click 'Pick All' in the 'Apply F/M' window.
    • As shown in the following figure, enter a value of 1 in the field 'VALI Pressure value at node I' then click 'OK'.
    The applied loads and constraints should now appear as shown in the figure below.Note:To have the constraints and loads appear each time you select 'Replot' you must change some settings. Select Utility Menu > PlotCtrls > Symbols.... In the window that appears, select 'Pressures' in the pull down menu of the 'Surface Load Symbols' section.
  7. Solve the System
  8. Solution > Solve > Current LSSOLVE

Postprocessing: Viewing the Results

  1. Plot Deformed ShapeGeneral Postproc > Plot Results > Deformed Shape
    PLDISP.2


  2. Plot Principle stress distributionAs shown previously, we need to use element tables to obtain principle stresses for line elements.
    1. Select General Postproc > Element Table > Define Table
    2. Click 'Add...'
    3. In the window that appears
      1. enter 'SMAXI' in the 'User Label for Item' section
      2. In the first window in the 'Results Data Item' section scroll down and select 'By sequence num'
      3. In the second window of the same section, select 'NMISC, '
      4. In the third window enter '1' anywhere after the comma
    4. click 'Apply'
    5. Repeat steps 2 to 4 but change 'SMAXI' to 'SMAXJ' in step 3a and change '1' to '3' in step 3d.
    6. Click 'OK'. The 'Element Table Data' window should now have two variables in it.
    7. Click 'Close' in the 'Element Table Data' window.
    8. Select: General Postproc > Plot Results > Line Elem Res...
    9. Select 'SMAXI' from the 'LabI' pull down menu and 'SMAXJ' from the 'LabJ' pull down menu
    Note:
    • ANSYS can only calculate the stress at a single location on the element. For this example, we decided to extract the stresses from the I and J nodes of each element. These are the nodes that are at the ends of each element.
    • For this problem, we wanted the principal stresses for the elements. For the BEAM3 element this is categorized as NMISC, 1 for the 'I' nodes and NMISC, 3 for the 'J' nodes. A list of available codes for each element can be found in the ANSYS help files. (ie. type help BEAM3 in the ANSYS Input window).
    As shown in the plot below, the maximum stress occurs in the middle of the beam with a value of 750 MPa.



    ANSYS Command Listing

    /title, Distributed Loading of a Beam
    /PREP7

    K,1,0,0 ! Define the keypoints
    K,2,1000,0

    L,1,2 ! Create the line

    ET,1,BEAM3 ! Beam3 element type

    R,1,100,833.333,10 ! Real constants - area,I,height

    MP,EX,1,200000 ! Young's Modulus
    MP,PRXY,1,0.33 ! Poisson's ratio

    ESIZE,100 ! Mesh size
    LMESH,ALL ! Mesh line

    FINISH
    /SOLU

    ANTYPE,0 ! Static analysis

    DK,1,UX,0,,,UY ! Pin keypoint 1
    DK,2,UY,0 ! Roller on keypoint 2

    SFBEAM,ALL,1,PRES,1 ! Apply distributed load

    SOLVE
    FINISH

    /POST1

    PLDISP,2 ! Plot deformed shape

    ETABLE,SMAXI,NMISC, 1 ! Create data for element table
    ETABLE,SMAXJ,NMISC, 3
    PLLS,SMAXI,SMAXJ,1,0 ! Plot ETABLE data

Effect of Self Weight on a Cantilever Beam



Introduction

This tutorial was completed using ANSYS 7.0 The purpose of the tutorial is to show the required steps to account for the weight of an object in ANSYS.
Loads will not be applied to the beam shown below in order to observe the deflection caused by the weight of the beam itself. The beam is to be made of steel with a modulus of elasticity of 200 GPa.

Preprocessing: Defining the Problem

  1. Give example a TitleUtility Menu > File > Change Title ...
    /title, Effects of Self Weight for a Cantilever Beam

  2. Open preprocessor menuANSYS Main Menu > Preprocessor
    /PREP7

  3. Define KeypointsPreprocessor > Modeling > Create > Keypoints > In Active CS...
    K,#,x,y,zWe are going to define 2 keypoints for this beam as given in the following table:


    KeypointCoordinates (x,y,z)
    1(0,0)
    2(1000,0)

  4. Create LinesPreprocessor > Modeling > Create > Lines > Lines > In Active Coord
    L,1,2Create a line joining Keypoints 1 and 2

  5. Define the Type of Element
  6. Preprocessor > Element Type > Add/Edit/Delete...For this problem we will use the BEAM3 (Beam 2D elastic) element. This element has 3 degrees of freedom (translation along the X and Y axes, and rotation about the Z axis).
  7. Define Real Constants
  8. Preprocessor > Real Constants... > Add...In the 'Real Constants for BEAM3' window, enter the following geometric properties:
    1. Cross-sectional area AREA: 500
    2. Area moment of inertia IZZ: 4166.67
    3. Total beam height: 10
    This defines a beam with a height of 10 mm and a width of 50 mm.
  9. Define Element Material PropertiesPreprocessor > Material Props > Material Models > Structural > Linear > Elastic > IsotropicIn the window that appears, enter the following geometric properties for steel:

    1. Young's modulus EX: 200000
    2. Poisson's Ratio PRXY: 0.3

  10. Define Element DensityPreprocessor > Material Props > Material Models > Structural > Linear > DensityIn the window that appears, enter the following density for steel:

    1. Density DENS: 7.86e-6

  11. Define Mesh SizePreprocessor > Meshing > Size Cntrls > ManualSize > Lines > All Lines...For this example we will use an element edge length of 100mm.
  12. Mesh the framePreprocessor > Meshing > Mesh > Lines > click 'Pick All'

Solution Phase: Assigning Loads and Solving

  1. Define Analysis Type
  2. Solution > Analysis Type > New Analysis > Static ANTYPE,0
  3. Apply Constraints
  4. Solution > Define Loads > Apply > Structural > Displacement > On KeypointsFix keypoint 1 (ie all DOF constrained)
  5. Define Gravity
  6. It is necessary to define the direction and magnitude of gravity for this problem.
    • Select Solution > Define Loads > Apply > Structural > Inertia > Gravity...
    • The following window will appear. Fill it in as shown to define an acceleration of 9.81m/s2 in the y direction.
      Note: Acceleration is defined in terms of meters (not 'mm' as used throughout the problem). This is because the units of acceleration and mass must be consistent to give the product of force units (Newtons in this case). Also note that a positive acceleration in the y direction stimulates gravity in the negative Y direction.
      There should now be a red arrow pointing in the positive y direction. This indicates that an acceleration has been defined in the y direction.
      DK,1,ALL,0,
      ACEL,,9.8
    The applied loads and constraints should now appear as shown in the figure below.
  7. Solve the System
  8. Solution > Solve > Current LS SOLVE

Postprocessing: Viewing the Results

  1. Hand CalculationsHand calculations were performed to verify the solution found using ANSYS:
    The maximum deflection was shown to be 5.777mm

  2. Show the deformation of the beamGeneral Postproc > Plot Results > Deformed Shape ... > Def + undef edge
    PLDISP,2

    As observed in the upper left hand corner, the maximum displacement was found to be 5.777mm. This is in agreement with the theortical value.

ANSYS Command Listing

/Title, Effects of Self Weight
/PREP7

Length = 1000
Width = 50
Height = 10

K,1,0,0 ! Create Keypoints
K,2,Length,0

L,1,2

ET,1,BEAM3 ! Set element type
R,1,Width*Height,Width*(Height**3)/12,Height !** = exponent
MP,EX,1,200000 ! Young's Modulus
MP,PRXY,1,0.3 ! Poisson's ratio
MP,DENS,1,7.86e-6 ! Density

LESIZE,ALL,Length/10, ! Size of line elements
LMESH,1 ! Mesh line 1

FINISH
/SOLU ! Enter solution mode

ANTYPE,0 ! Static analysis
DK,1,ALL,0, ! Constrain keypoint 1
ACEL,,9.8 ! Set gravity constant

SOLVE
FINISH

/POST1
PLDISP,2 ! Display deformed shape

solid model of the Spindle Base

Problem Description B

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

Geometry Generation

We will create this model by creating the base and the back and then the rib.

Create the Base

  1. Create the base rectangle
    WP X (XCORNER)WP Y (YCORNER)WIDTHHEIGHT
    00109102
  2. Create the curved edge (using keypoints and lines to create an area)
    • Create the following keypoints
      XYZ
      Keypoint 5-20820
      Keypoint 6-20200
      Keypoint 70820
      Keypoint 80200
      You should obtain the following:
    • Create arcs joining the keypointsMain Menu > Preprocessor > (-Modeling-) Create > (-Lines-) Arcs > By End KPs & Rad
      • Select keypoints 4 and 5 (either click on them or type 4,5 into the command line) when prompted.
      • Select Keypoint 7 as the center-of-curvature when prompted.
      • Enter the radius of the arc (20) in the 'Arc by End KPs & Radius' window
      • Repeat to create an arc from keypoints 1 and 6
      (Alternatively, type LARC,4,5,7,20 followed by LARC,1,6,8,20 into the command line)
    • Create a line from Keypoint 5 to 6Main Menu > Preprocessor > (-Modeling-) Create > (-Lines-) Lines > Straight Line
      L,5,6
    • Create an Arbitrary area within the bounds of the linesMain Menu > Preprocessor > (-Modeling-) Create > (-Areas-) Arbitrary > By Lines
      AL,4,5,6,7
    • Combine the 2 areas into 1 (to form Area 3)Main Menu > Preprocessor > (-Modeling-) Operate > (-Booleans-) Add > Volumes
      AADD,1,2
    You should obtain the following image:
  3. Create the 4 holes in the baseWe will make use of the 'copy' feature in ANSYS to create all 4 holes
    • Create the bottom left circle (XCENTER=0, YCENTER=20, RADIUS=10)
    • Copy the area to create the bottom right circle (DX=69)(AGEN,# Copies (include original),Area#,Area2# (if 2 areas to be copied),DX,DY,DZ)
    • Copy both circles to create the upper circles (DY=62)
    • Subtract the three circles from the main base(ASBA,3,ALL)
    You should obtain the following:
  4. Extrude the basePreprocessor > (-Modeling-) Operate > Extrude > (-Areas-) Along Normal
      The following window will appear once you select the area
    • Fill in the window as shown (length of extrusion = 26mm). Note, to extrude the area in the negative z direction you would simply enter -26.
    (Alternatively, type VOFFST,6,26 into the command line)

Create the Back

  1. Change the working planeAs in the previous example, we need to change the working plane. You may have observed that geometry can only be created in the X-Y plane. Therefore, in order to create the back of the Spindle Base, we need to create a new working plane where the X-Y plane is parallel to the back. Again, we will define the working plane by aligning it to 3 Keypoints.
    • Create the following keypoints
      XYZ
      #1001091020
      #10110920
      #102159102sqrt(3)/0.02

    • Align the working plane to the 3 keypointsRecall when defining the working plane; the first keypoint defines the origin, the second keypoint defines the x-axis orientation, while the third defines the orientation of the working plane.
      (Alternatively, type KWPLAN,1,100,101,102 into the command line)
  2. Create the back area
    • Create the base rectangle (XCORNER=0, YCORNER=0, WIDTH=102, HEIGHT=180)
    • Create a circle to obtain the curved top (XCENTER=51, YCENTER=180, RADIUS=51)
    • Add the 2 areas together
  3. Extrude the area (length of extrusion = 26mm)Preprocessor > (-Modeling-) Operate > Extrude > (-Areas-) Along Normal
    VOFFST,27,26
  4. Add the base and the back together
    • Add the two volumes togetherPreprocessor > (-Modeling-) Operate > (-Booleans-) Add > Volumes
      VADD,1,2
      You should now have the following geometry
      Note that the planar areas between the two volumes were not added together.
    • Add the planar areas together (don't forget the other side!)Preprocessor > (-Modeling-) Operate > (-Booleans-) Add > Areas
      AADD, Area 1, Area 2, Area 3
  5. Create the Upper Cylinder
    • Create the outer cylinder (XCENTER=51, YCENTER=180, RADIUS=32, DEPTH=60)Preprocessor > (-Modeling-) Create > (-Volumes-) Cylinder > Solid Cylinder
      CYL4,51,180,32, , , ,60
    • Add the volumes together
    • Create the inner cylinder (XCENTER=51, YCENTER=180, RADIUS=18.5, DEPTH=60)
    • Subtract the volumes to obtain a hole
    You should now have the following geometry:

Create the Rib

  1. Change the working plane
    • First change the active coordinate system back to the global coordinate system (this will make it easier to align to the new coordinate system)Utility Menu > WorkPlane > Align WP with > Global Cartesian(Alternatively, type WPCSYS,-1,0 into the command line)
    • Create the following keypoints
      XYZ
      #200-206126
      #20106126
      #202-206130

    • Align the working plane to the 3 keypointsRecall when defining the working plane; the first keypoint defines the origin, the second keypoint defines the x-axis orientation, while the third defines the orientation of the working plane.
      (Alternatively, type KWPLAN,1,200,201,202 into the command line)
  2. Change active coordinate systemWe now need to update the coordiante system to follow the working plane changes (ie make the new Work Plane origin the active coordinate)
    Utility Menu > WorkPlane > Change Active CS to > Working Plane
    CSYS,4
  3. Create the area
    • Create the keypoints corresponding to the vertices of the rib
      XYZ
      #203129-(0.57735*26)00
      #204129-(0.57735*26) + 38sqrt(3)/2*760

    • Create the rib area through keypoints 200, 203, 204Preprocessor > (-Modeling-) Create > (-Areas-) Arbitrary > Through KPs
      A,200,203,204
  4. Extrude the area (length of extrusion = 20mm)
  5. Add the volumes together
You should obtain the following:

solid model of the pulley

Solid Model Creation


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.

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, HEIGHT
    The geometry of the rectangles:
    Rectangle 1Rectangle 2Rectangle 3
    WP X (XCORNER)238
    WP Y (YCORNER)020
    WIDTH150.5
    HEIGHT5.515

    You should obtain the following:
  2. Add the AreasMain Menu > Preprocessor > (-Modeling-) Operate > (-Boolean-) Add > Areas
    AADD, ALL
    ANSYS 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,RAD
    The geometry of the circles:
    Circle 1Circle 2
    WP X (XCENTER)38.5
    WP Y (YCENTER)5.50.2
    RADIUS0.50.2

  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
      XYZ
      #2001030
      #2002130
      #2003031

    • 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:

Modeling Tools

Introduction

This tutorial was completed using ANSYS 7.1 The purpose of the tutorial is to show several modeling tools available in ANSYS.
Three methods will be shown to create the meshed plate shown below.

Using Cutlines in ANSYS

  1. Give example a TitleUtility Menu > File > Change Title ...
    /title, meshing a plate using cutlines

  2. Open preprocessor menuANSYS Main Menu > Preprocessor
    /PREP7

  3. Create a block at origin (0,0) with a width and height of 1Preprocessor > Modeling > Create > Areas > Rectangle > By 2 Corners...
    blc4,0,0,1,1

  4. Divide the area into 4 parts using 2 diagonal lines
    • Create a line Preprocessor > Modeling > Create > Lines > Lines > Straight Line
    • Select the top left keypoint and draw the line to the bottom right keypoint by clicking on that keypoint
    • Now divide the area into 2 areas using the line by selecting Preprocessor > Modeling > Operate > Booleans > Divide > Area by Line
    • Select the area and click OK in the 'Divide Area by Line' window
    • Now select the line and click OK in the 'Divide Area by Line' windowThe area is now divided into 2 as shown in the figure below. A warning may appear with the statement "Line 5 is attached to 2 area(s) and cannot be deleted. This is expected because the command which divides the area deletes the line used to create the area. However, in this case, the line is required to define the new areas. Click OK and ignore the warning.

    • Now we need to further divide the 2 areas to make 4 areas. Using the same method, create a line from the top right keypoint to the bottom left. Be sure to select both areas to divide, otherwise, you will have to create the line again to divide the second area.

  5. Define the Type of Element
  6. Preprocessor > Element Type > Add/Edit/Delete... > Add... > Structural Mass, Solid > Quad 4node 42For this problem we will use the PLANE42 (2D plane stress or plane strain) element. This element has 4 nodes each with 2 degrees of freedom(translation along the X and Y axes).
  7. Select Plane Stress with Thickness
  8. In the Element Types window, select Options... and in Element behavior select Plane strs w/thk
  9. Define Real Constants
  10. Preprocessor > Real Constants > Add/Edit/Delete > Add... > OKIn the 'Real Constants for PLANE42' window, enter the thickness: 0.1
  11. Define Element Material PropertiesPreprocessor > Material Props > Material Models > Structural > Linear > Elastic > IsotropicIn the window that appears, enter the following geometric properties for steel:
    1. Young's modulus EX: 200000
    2. Poisson's Ratio PRXY: 0.3

  12. Define Mesh SizePreprocessor > Meshing > Size Cntrls > ManualSize > Lines > All Lines...To obtain the desired mesh we need to set NDIV to 2
  13. Create a hardpointPreprocessor > Modeling > Create > Keypoints > Hard PT on line > Hard PT by ratioFor demonstration purposes only, we are going to create a hardpoint on one of the diagonal lines. Select the bottom right diagonal line and enter a ratio of 0.41 This will ensure the creation of a node at a location 41% down the line
  14. Mesh the framePreprocessor > Meshing > Mesh > Areas > click 'Pick All'
    amesh,all
    The mesh should then appear as shown below. Note that the node is not at the midway point on the bottom right diagonal line due to the hardpoint.

Merging Objects in ANSYS

  1. Clear the memory and start a new modelUtility Menu > File > Clear & Start New ...
    /clear

  2. Give example a TitleUtility Menu > File > Change Title ...
    /title, meshing a plate by copying elements

  3. Open preprocessor menuANSYS Main Menu > Preprocessor
    /PREP7

  4. Define KeypointsPreprocessor > Modeling > Create > Keypoints > In Active CS...
    K,#,x,y,zWe are going to define 3 keypoints as given in the following table:

    KeypointCoordinates (x,y)
    1(0,0)
    2(1,0)
    3(0.5,0.5)

  5. Create AreaPreprocessor > Modeling > Create > Areas > Arbitrary > Through KPs
    a,k1,k2,k3...We are going to define an area through keypoints 1,2,3. Select keypoints 1,2 and 3 and then select 'OK'.

  6. Define the Type of Element
  7. Preprocessor > Element Type > Add/Edit/Delete... > Add... > Structural Mass, Solid > Quad 4node 42As in the previous mesh, we will use the PLANE42 (2D plane stress or plane strain) element. This element has 4 nodes each with 2 degrees of freedom(translation along the X and Y axes).
  8. Select Plane Stress with Thickness
  9. In the Element Types window, select Options... and in Element behavior select Plane strs w/thk
  10. Define Real Constants
  11. Preprocessor > Real Constants > Add/Edit/Delete > Add... > OKIn the 'Real Constants for PLANE42' window, enter the thickness: 0.1
  12. Define Element Material PropertiesPreprocessor > Material Props > Material Models > Structural > Linear > Elastic > IsotropicIn the window that appears, enter the following geometric properties for steel:
    1. Young's modulus EX: 200000
    2. Poisson's Ratio PRXY: 0.3

  13. Define Mesh SizePreprocessor > Meshing > Size Cntrls > ManualSize > Lines > All Lines...To obtain the desired mesh we need to set NDIV to 2
  14. Mesh the areaPreprocessor > Meshing > Mesh > Areas > click 'Pick All'
    amesh,all


  15. Mirror the geometry
    • Create local coord system to mirror geom.
      Select: Utility Menu > WorkPlane > Local Coordinate Systems > Create Local CS > At specified Loc
    • We are first going to mirror the geometry about the diagonal from node 1 to 4. Click on the lower left node (bottom corner) and select 'OK'
    • As shown below, create a coordinate system rotated 45 degrees about Z
    • Next, mirror the geometry
      Select: Preprocessor > Modeling > Reflect > Areas Click 'Pick All'
    • In the window that appears select X-Z plane Y and click 'OK'. This will mirror the geometry about the X-Z plane
    • Use the same technique to obtain the full geometry

  16. Re-activate the global coordinate systemUtility Menu > WorkPlane > Change Active CS to > Global Cartesian
    csys,0

  17. Plot ElementsUtility Menu > Plot > ElementsYour mesh should now appear as follows:

    However, you are not done! If you plot the node numbers you will note that some duplicate nodes exist (created in mirroring).

  18. Merge duplicate nodes/elementsPreprocessor > Numbering Ctrls > Merge Items > All
    nummrg,all

Gluing Areas in ANSYS

  1. Clear the memory and start a new modelUtility Menu > File > Clear & Start New ...
    /clear

  2. Give example a TitleUtility Menu > File > Change Title ...
    /title, meshing a plate by copying areas

  3. Open preprocessor menuANSYS Main Menu > Preprocessor
    /PREP7

  4. Define KeypointsPreprocessor > Modeling > Create > Keypoints > In Active CS...
    K,#,x,y,zWe are going to define 7 keypoints as given in the following table:

    KeypointCoordinates (x,y)
    1(0,0)
    2(0.5,0)
    3(1,0)
    4(0.75,0.25)
    5(0.5,0.5)
    6(0.25,0.25)
    7(0.5,0.166667)

  5. Create AreaPreprocessor > Modeling > Create > Areas > Arbitrary > Through KPs
    a,k1,k2,k3...Now we are going to define 3 areas; (1,2,7,6), (2,3,4,7), (4,5,6,7)

  6. Mirror the geometry
    • As shown in the previous section, create a local coordinate system and mirror the geometry
      Utility Menu > WorkPlane > Local Coordinate Systems > Create Local CS > At specified Loc
    • Then, mirror the geometry, select: Preprocessor > Modeling > Reflect > Areas
    • Do this twice to obtain the full geometry

  7. Re-activate the global coordinate systemUtility Menu > WorkPlane > Change Active CS to > Global Cartesian
    csys,0

  8. Glue the areas togetherPreprocessor > Modeling > Operate > Booleans > Glue > Areas
    aglue,allWe need to glue the areas together so that the areas are attached but that the subdivided areas remain to give us the elements we want

  9. Define the Type of Element
  10. Preprocessor > Element Type > Add/Edit/Delete... > Add... > Structural Mass, Solid > Quad 4node 42As in the previous mesh, we will use the PLANE42 (2D plane stress or plane strain) element. This element has 4 nodes each with 2 degrees of freedom(translation along the X and Y axes).
  11. Select Plane Stress with Thickness
  12. In the Element Types window, select Options... and in Element behavior select Plane strs w/thk
  13. Define Real Constants
  14. Preprocessor > Real Constants > Add/Edit/Delete > Add... > OKIn the 'Real Constants for PLANE42' window, enter the thickness: 0.1
  15. Define Element Material PropertiesPreprocessor > Material Props > Material Models > Structural > Linear > Elastic > IsotropicIn the window that appears, enter the following geometric properties for steel:
    1. Young's modulus EX: 200000
    2. Poisson's Ratio PRXY: 0.3

  16. Define Mesh SizePreprocessor > Meshing > Size Cntrls > ManualSize > Areas > All Areas...To obtain the desired mesh we need to set SIZE to 1
  17. Mesh the areaPreprocessor > Meshing > Mesh > Areas > click 'Pick All'
    amesh,all
    And again we obtain the desired mesh: