WS9-1 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation WORKSHOP 9 TOPOLOGY OPTIMIZATION

WS9-2 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation

WS9-3 PAT328, Workshop 9, September 2004 Copyright 2004 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

WS9-4 PAT328, Workshop 9, September 2004 Copyright 2004 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.

WS9-5 PAT328, Workshop 9, September 2004 Copyright 2004 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

WS9-6 PAT328, Workshop 9, September 2004 Copyright 2004 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

WS9-7 PAT328, Workshop 9, September 2004 Copyright 2004 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

WS9-8 PAT328, Workshop 9, September 2004 Copyright 2004 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

WS9-9 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation Step 3. Meshing with QUAD4 Elements and Equivalence a.Elements: Equivalence / All / Tolerance Cube b.Apply b a

WS9-10 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation Step 4. Create Boundary Conditions Create a boundary condition on the left end of the bridge as shown lb

WS9-11 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation Step 4. Create Boundary Conditions Create a boundary condition on the right end of the bridge as shown lb

WS9-12 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation Step 5. Create a force Apply a force of 2000 lbs at the mid-span of the bridge lb

WS9-13 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation The model should look similar to the picture below.

WS9-14 PAT328, Workshop 9, September 2004 Copyright 2004 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

WS9-15 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation Step 7. Defining Element Properties Create a 2D shell property with a thickness of 6 in.

WS9-16 PAT328, Workshop 9, September 2004 Copyright 2004 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

WS9-17 PAT328, Workshop 9, September 2004 Copyright 2004 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

WS9-18 PAT328, Workshop 9, September 2004 Copyright 2004 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

WS9-19 PAT328, Workshop 9, September 2004 Copyright 2004 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

WS9-20 PAT328, Workshop 9, September 2004 Copyright 2004 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 d a b c d

WS9-21 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation Step 9. Read Optimization Results Import the results: a.File / Import b.Results / PATRAN 2.els… c.Select topo.res_tmpl d.OK. e.Type *.des in the File Name Field and click Apply to display the correct file. f.Select the bridge.des file g.Apply a b c d e f g

WS9-22 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation Step 10. Plot Results Create a Fringe Plot. a.Results: Create / Fringe b.Apply c.Select Plot Options d.Set Averaging Definition Domain to None. e.Apply again c a b d

WS9-23 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation Step 10. Plot Results Averaged Plot.

WS9-24 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation Step 10. Plot Results Un-averaged Plot.

WS9-25 PAT328, Workshop 9, September 2004 Copyright 2004 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

WS9-26 PAT328, Workshop 9, September 2004 Copyright 2004 MSC.Software Corporation