WS3-1 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation WORKSHOP 3 TOPOLOGY OPTIMIZATION

WS3-2 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation

WS3-3 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Problem Description u A new bridge is being designed. The designer wants to come up with a preliminary design which is stiff and has good load path. The available material envelop is 120 x 60 x 6. The loading and boundary conditions are show below: 2000 lb

WS3-4 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Suggested Exercise Steps 1. Start MSC.Patran and create a new database bridge.db. 2. Create two surfaces representing the raw material. 3. Mesh the surfaces using QUAD4 elements and equivalence. 4. Create boundary conditions. 5. Apply a force at the mid-span. 6. Create an steel material with Elastic Modulus of 29e6 and Poisson ratio of Create a shell property with a thickness of 6 inches. 8. Set up and run analysis. 9. Read in optimization results 10. Plot the results 11. Exploration.

WS3-5 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 1. Create a Database Create a new database. a.File / New. b.Enter bridge as the file name. c.Click OK. d.Choose Default Tolerance. e.Select MSC.Nastran as the Analysis Code. f.Select Structural as the Analysis Type. g.Click OK. a b e f d c g

WS3-6 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 2. Create geometry for raw material a.Geometry: Create / Surface / XYZ. b.Click on Vector Coordinates List and enter. c.Apply. a b c

WS3-7 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 2. Create geometry for raw material (Cont.) a.Click on the lower right hand vertex of surface 1. b.A second 60x60 surface is automatically created. a

WS3-8 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 3. Meshing with QUAD4 Elements and Equivalence a.Elements: Create / Mesh / Surface. b.Select Elem Shape: Quad. Mesher: IsoMesh. Topology: Quad4. c.Click on Surface List and rectangular select both surfaces. d.Enter a global edge length of 1.5. e.Apply. b c d a e

WS3-9 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 3. Meshing with QUAD4 Elements and Equivalence a.Elements: Equivalence / All / Tolerance Cube b.Apply b a

WS3-10 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 4. Create Boundary Conditions Create a boundary condition on the left end of the bridge as shown lb

WS3-11 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 4. Create Boundary Conditions Create a boundary condition on the right end of the bridge as shown lb

WS3-12 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 5. Create a force Apply a force of 2000 lbs at the mid-span of the bridge lb

WS3-13 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation The model should look similar to the picture below.

WS3-14 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 6. Defining the Material Create a material called Steel with the following properties: Elastic Modulus = 29E6 Poisson Ratio = 0.3 Density = 0.3

WS3-15 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 7. Defining Element Properties Create a 2D shell property with a thickness of 6 in.

WS3-16 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 8. Set up and run Analysis Set up the Topology Optimization Run a.Analysis: Optimize / Entire Model / Full Run. b.Select Customized Solutions… c.Select Use Customized Solutions. a b c

WS3-17 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 8. Set up and run Analysis cont. a.Click on Design Domain… b.Click on the plate property to send it to the Design Domain below c.OK a c b

WS3-18 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 8. Set up and run Analysis cont. a.Click on Objectives_Constraints… b.Select Static Analysis c.Enter 0.4 for Mass Target d.OK a c b a d

WS3-19 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 8. Set up and run Analysis cont. a.Click on Optimization Control… b.Use all defaults c.OK d.OK again a c a b d

WS3-20 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 8. Set up and run Analysis cont. a.Click on Subcase Select… b.Click on the Default subcase to select it. c.OK d.Apply a b c d

WS3-21 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 9. Read Optimization Results Import the results: a.Tools / Design Study / Post- Process… b.Read Results / Results Entities c.Select Results File… d.Select bridge.des e.OK. f.Apply a b c d e f

WS3-22 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 10. Display Optimization Results Display the results: a.Display Results / Results Entities b.Select the result case. c.Enter 0.3 for the threshold. d.Apply a b c d

WS3-23 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 10. Display Optimization Results Smooth the results: a.FEM Smooth / Results Entities / 2D b.Select the result case. c.Select all of the elements. d.Apply a b c d

WS3-24 PAT328, Workshop 3, May 2005 Copyright 2005 MSC.Software Corporation Step 11. Exploration Try a different Analysis Discipline u Select Normal Modes instead of Static n Try different parameters u Instead of the 2:1 geometry aspect ratio, try a different aspect ratio. u Try a different material u Try a different thickness u Try a different loading u Try a different mesh size u Try different Mass Targets