WS11-1 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation WORKSHOP 11 SPACECRAFT FAIRING

WS11-2 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation

WS11-3 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation l Workshop Objectives l Learn to use Groups and Lists

WS11-4 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation l Problem Description l In this exercise, a spacecraft fairing will be constructed. Curves and surfaces will be used to define the fairing geometry. The finite element model will consist of 2-dimensional elements with 1- dimensional elements applied at various edges of the geometry. The 1-dimensional elements will represent stiffeners for the structure.

WS11-5 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation l Suggested Exercise Steps 1. Create a new database called fairing.db and set the model preferences. 2. Create the model geometry. 3. Create the mesh seeds for the model. 4. IsoMesh the model using Quad4 topology. 5. Check the free edges, equivalence the model, and then check the free edges again. 6. Create a new group called FEM that contains only the finite elemental model. Then post only the FEM group. 7. Create two material properties, alum_1 and alum_2. 8. Create two fields, one for temperature and the other for thickness. 9. Create element properties. 10. Create a temperature boundary condition. 11. Create a series of lists containing elements that satisfy these following requirements: 1) the elements are made up of the alum_1 material, 2) the elements are greater than 0.98 in thickness, and 3) the elements have a temperature greater than degrees. 12. Intersect lists a and b to produce a list of elements that satisfy the first two conditions.

WS11-6 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation l Suggested Exercise Steps (Cont.) 13. Create another list that satisfies the third condition. 14. Intersect the new list with the other list to produce a group of elements that satisfy all three conditions. Then, place these elements in a separate group. 15. Post the group containing the elements produced in step Create 2 new groups, each containing elements with different property sets. 17. Change the display attributes for each group. 18. Post each group separately, then post both groups together.

WS11-7 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 1. Create New Database Create a new database and set the model preferences. a.File: New. b.Enter fairing for the File Name. c.Click OK. d.Set the Tolerance to Default. e.Make sure that the Analysis Code and Analysis Type are set to MSC.Nastran and Structural, respectively. f.Click OK. a b c d e f

WS11-8 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 2. Create Model Geometry Create the points and curves that represent the outline of the fairing. a.Geometry: Create / Point / XYZ. b.Enter [30 0 0] under Point Coordinates List and click Apply. c.Geometry: Create / Curve / XYZ. d.Enter and [ ] under Vector Coordinates List and Origin Coordinates List, respectively. e.Click Apply. f.Click on Cycle Show Labels icon. g.Click on Point Size icon to increase the point size. h.Geometry : Create / Curve / Point. i.Click on Point 1 under Starting Point List and click on Point 2 for Ending Point List. a b c d e h i j f g

WS11-9 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 2. Create Model Geometry (Cont.) Illustrated here are curves that represent the basic geometry for the fairing. These curves will be revolved 360º in order to get the final model.

WS11-10 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 2. Create Model Geometry (Cont.) Create the fairing by revolving curves 1 and 2 about the fairings vertical center line. a.Geometry: Create / Surface / Revolve. b.Enter Coord 0.2 for Axis c.Enter 360 for the Total Angle. d.Click on Curve List. e.Click on Curve 1, then click on Curve 2. f.Viewing: Angles. g.Enter under Angles. h.Click Apply. a b c d e f g

WS11-11 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 2. Create Model Geometry (Cont.) Change the display preferences in order to get a clearer visual of the model. a.Display: Geometry… b.Enter 3 for Number of Display Lines c.Click Apply, then Cancel. a b c

WS11-12 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 3. Create Mesh Seeds Create a finite element mesh so that 4 node Quad elements are created every 10° along the circumferential edges. a.Elements: Create / Mesh Seed / Uniform. b.Select Number of Elements and enter 36 for the Number. c.Click on Curve List. d.Select the top circumferential edge of the fairing (Surface 1.3). a b c d

WS11-13 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 3. Create Mesh Seeds (Cont.) In the vertical direction (y-direction), define a smoothly transitioning mesh density. The elements along the top of the cylinder are 2.5 times as large as those along the bottom edge (tapered end) of the fairing. a.Elements : Create / Mesh Seed / One Way Bias. b.Select L1 and L2 and enter 7 and 10 for L1 and L2, respectively. c.Click on Curve List and select Curve 1. d.Elements : Create / Mesh Seed / One Way Bias. e.Select L1 and L2 and enter 4 and 7 for L1 and L2, respectively. f.Click on Curve List and select Curve 2. a c b d e f

WS11-14 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 4. Create a Mesh for the Model Now that the mesh seeds have been created, mesh the model using Quad4 topology. a.Elements: Create / Mesh / Surface. b.Select Quad, IsoMesh, and Quad4. c.Rectangular pick the entire model and click Apply. d.Remove the display lines by clicking the on the Display lines icon. e.Remove the labels by clicking the Cycle Show labels icon. f.Decrease the point-size by clicking on the Point Size icon. a b c e d f c

WS11-15 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 4. Create a Mesh for the Model (Cont.) Mesh the horizontal (circumferential) edges of each surface with two-noded bar elements. a.Click on Plot/Erase icon. b.Click on Erase under FEM. c.Click OK. d.Elements: Create / Mesh / Curve. e.Set Topology to Bar2 f.Shift select the 3 curves (as indicated). g.Click Apply. c d e f g a f b

WS11-16 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 5. Observe the Free Edges Check the free edges of the model, equivalence, and then check the free edges again. a.Click on the Plot/Erase Icon. b.Under FEM, click Plot. c.Elements : Verify / Element / Boundaries. d.Select Free Edges under Display Type. e.Click Apply. f.Elements : Equivalence / All / Tolerance Cube. g.Click Apply. h.Repeat steps c through e. c d e f g a b

WS11-17 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 6. Create a New Group Replot the FEM and create a group called FEM containing only the finite element model. Post only this new group to the viewport. a.Group: Create… b.Enter FEM for the New Group Name. c.Select Unpost All Other Groups. d.Change Group Contents to Add All FEM. e.Click Apply. a b c d e

WS11-18 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 7. Create Material Properties Create the first material for the model. Material alum_1 will be applied to the top(cylindrical) portion of the fairing. a.Materials: Create / Isotropic / Manual Input. b.Enter alum_1 for the Material Name. c.Click on Input Properties. d.Select Linear Elastic and enter 1.05E7, 0.33, and 2.6E-4, for Elastic Modulus, Poisson Ratio, and Density, respectively. e.Click OK. f.Click Apply. d e a b c f

WS11-19 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 7. Create Material Properties (Cont.) Create the second material for the model. Material alum_2 will be applied to the bottom (tapered) portion of the fairing. a.Materials: Create / Isotropic / Manual Input. b.Enter alum_2 for the Material Name. c.Click on Input Properties. d.Select Linear Elastic and enter 1.18E7, 0.33, and 2.4E-4, for Elastic Modulus, Poisson Ratio, and Density, respectively. e.Click OK. f.Click Apply. d e a b c f

WS11-20 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 8. Create Fields Define a field that represents the varying thickness. a.Fields: Create / Spatial / PCL Function. b.Enter thickness for the Field Name. c.Enter 1.5-Y/160 for the Scalar Function and click Apply. a b c

WS11-21 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 8. Create Fields Plot the function defined in the field. a.Field: Show b.Select thickness as the field to show. c.Click Specify Range. d.Enter for the maximum and 20 for the number of points. e.Click OK. f.Click Apply. d e a b c f

WS11-22 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 8. Create Fields Delete the plot. a.XY Plot: Delete / XYWindow b.Select XY Result Window. c.Click Apply. d.Choose Yes to delete the result window. a b c d

WS11-23 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Define a field that represents the varying temperature distribution. a.Fields: Create / Spatial / PCL Function. b.Enter temperature for the Field Name. c.Enter (150.0/160.0)*X for the Scalar Function and click Apply. Step 8. Create Fields a b c

WS11-24 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 8. Create Fields Plot the function defined in the field. a.Field: Show b.Select temperature as the field to show. c.Click Specify Range. d.Enter 50.0 for the maximum and 10 for the number of points. e.Click OK. f.Click Apply. b d e c a f

WS11-25 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 9. Create Element Properties Create two element properties which include the material definitions and varying thickness. a.Properties: Create / 2D / Shell. b.Enter prop_1 for the Property Set Name. c.Click on Input Properties. d.Click on the Select Material icon. e.Select alum_1 from the Select Material list box. f.Click on the Front view icon. f d e a b c

WS11-26 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 9. Create Element Properties (Cont.) Finish creating the first property set. a.Set the thickness type to Element Nodal and click on the Select Field icon. b.Select thickness as the Scalar Spatial Field. c.Click OK. d.Click on Select Members and click on the Shell Element icon. e.Select the top(cylindrical) portion of the fairing by dragging a box around the desired section (as indicated on next page). f.Click Add, then Apply. a d b c d f f

WS11-27 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 9. Create Element Properties (Cont.) Illustrated here is the desired application region for the first property set.

WS11-28 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 9. Create Element Properties (Cont.) Create the second property set. a.Properties: Create / 2D / Shell. b.Enter prop_2 for the Property Set Name. c.Click on Input Properties… d.Click on the Select Material Icon. e.Select alum_2 from the Existing Materials. f.Click on the Select Field Icon g.Select thickness from the Existing Fields box. h.Click OK. i.Click on Select Members and select the bottom (tapered) portion of the fairing by dragging a box around it(as indicated on next page). j.Click Add, then Apply d f e g h a b c i j

WS11-29 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 9. Create Element Properties (Cont.) Shown here are the elements for the desired application region of the second property set.

WS11-30 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 10. Create Temperature Boundary Conditions Define the models varying temperature distribution. a.Loads/BCs: Create / Temperature / Nodal. b.Enter temp for the New Set Name. c.Click on Input Data. d.Click on Temperature and select temperature from the Spatial Fields. e.Click OK. f.Click on Select Application Region. g.Under Geometry Filter, select FEM. h.Click on Application Region and select the entire model. i.Click Add, then, OK j.Click Apply. d e g h i a b c f j

WS11-31 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 10. Create Temperature Boundary Conditions (Cont.) Turn off the temperature labels in order to get a better visualization of the model. a.Display: Load/BC/Elem. Prop… b.Under Loads/BCs remove check under Temperature. c.Click Apply, then Cancel. a b c

WS11-32 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 11. Create Lists Use Lists and groups to filter then group the quad elements that have the following attributes: Material : alum_1 Thickness : > 0.98 Temperature : >230.0 a.Tools : List / Create… b.FEM / Element / Attribute c.Under Attribute, select Material. d.Under Existing Materials, select alum_1. e.Set the Target List to A and click Apply. a b c d e The contents of List A compose of elements that satisfy the first condition; they are made up of the alum_1 material.

WS11-33 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 11. Create Lists (Cont.) Define List B to include only the Quad elements that have a thickness greater than a.Properties: Show. b.Under Existing Properties, select Thickness. c.Set Display Method to Scalar Plot. d.Select Current Viewport, select FEM and click Apply. a b c d Shown above is a fringe plot the model by thickness. Those elements that are thicker than 0.98 will be included in the next list.

WS11-34 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 11. Create Lists (Cont.) After defining the list parameters, add the elements greater than 0.98 in thickness to list B. a.Tools: List / Create… b.FEM / Element / Attribute. c.Under Attribute, select Fringe Value. d.Under Fringe Tools, select default_Fringe. e.Change the inequality to > and enter f.Select B for the Target List. g.Click on Apply. a The contents of List B include all elements thicker than b c d e f g

WS11-35 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 12. Intersect Lists Intersect Lists A and B and replace the contents of List A with the elements found in the intersection. a.Tools: List / Boolean… b.Click on the Intersect icon. c.Click on Replace A. The new List A is composed of elements that satisfy both requirements: they are made up of alum a b c

WS11-36 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 13. Create More Lists Perform a final classification of the elements. Isolate those elements that satisfy the third condition of the applied temperature load > a.Loads/BCs: Plot Contours / Temperature. b.Select temp from the Existing Sets. c.Select Temperature under Select Data Variable. d.Select the FEM group and click Apply. a b c d

WS11-37 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 13. Create More Lists (Cont.) Clear the contents of List B and add the values obtained from the final classification. a.Tools: List / Create. b.FEM / Element / Attribute. c.Select Fringe Value and default_Fringe for Attribute and Fringe Tools respectively. d.Change the inequality to > and enter e.Select B for the Target List. f.Click on Clear on the List B form g.Click Apply on the List Create form. a b c d e f g

WS11-38 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 14. Intersect Lists Again Lists A and B will be intersected again to create a List C. This list will contain the elements that satisfy all three conditions. The contents of List C will then be placed into a new group called common_quads. a.Tools: List / Boolean… b.Click Clear. c.Click on the Intersect icon (It may be necessary to click on any of the other icons first). d.Click on Add To Group… e.Enter common_quads for the Group Name. f.Click Apply, then Cancel. a b c d e f

WS11-39 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 15. Post Group Post the common_quad group. This is the group of elements that satisfy all three of the conditions defined earlier. a.Group: Post… b.Select the common_quads group under Select Groups to Post. c.Click Apply, then Cancel. d.Click on the Iso 1 view icon. a b c d

WS11-40 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 15. Post Group (Cont.) This is the Iso 1 view of the elements in the common_quads group. These are all the elements that satisfied all three conditions.

WS11-41 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 16. Create Two New Groups Create two new groups, prop1_group and prop2_group.Then, change the display attributes for each group. a.Click on the Reset Graphics icon. b.Group: Create… c.Create / Property Set. d.Enter prop1_group for the Group Name. e.Select prop_1 under Property Sets. f.Click Apply. g.Repeat steps b through f entering prop2_group for the Group Name and selecting prop_2 under Property Sets. a b c d e f g

WS11-42 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 17. Change the Display Attributes Set the entity coloring and labeling to Group mode and then change the display attributes for each of the two new groups. a.Display: Entity / Color / Label / Render… b.Select Group under Entity Color and Labeling. c.Select the prop1_group under the Target Group(s). d.Select HiddenLine for the Render Style and select dark blue for the Shade Color. e.Click Apply. f.Select the prop2_group for the Target Group(s). g.Select Wireframe for the Render Style and select red for the Shade Color. h.Click Apply, then, Cancel. a b c d e f g h

WS11-43 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 18. Post Groups Change views and post the prop1_group. a.Click on the Iso 3 view icon. b.Group : Post… c.Under Select Groups to Post, select prop1_group. d.Click Apply. a b c d

WS11-44 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 18. Post Groups (Cont.) Post only the prop2_group. a.Group: Post… b.Under Select Groups to Post, select prop2_group. c.Click Apply. a b c

WS11-45 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation Step 18. Post Groups (Cont.) Post both the prop1_group and the prop2_group. a.Group: Post… b.Under Select Groups to Post, select both prop1_group and prop2_group. c.Click Apply. a b c

WS11-46 NAS120, Workshop 11, May 2006 Copyright 2005 MSC.Software Corporation