WS1c-1 WORKSHOP 1C NORMAL MODES ANALYSIS WITH FINE MESH NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation. - презентация

1 WS1c-1 WORKSHOP 1C NORMAL MODES ANALYSIS WITH FINE MESH NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation

2 WS1c-2 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation

3 WS1c-3 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation NORMAL MODES ANALYSIS n Problem Description u For this problem, we will repeat the procedures of Workshop 1b, except that the model will be meshed with a Global Edge Length of 0.1. The goal is to see the difference between a fine meshed model and a coarse meshed model.

4 WS1c-4 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation NORMAL MODES ANALYSIS n Suggested Exercise Steps 1. Import the model definition from Workshop 1a. 2. Delete the existing finite elements. 3. Mesh the surface with a Global Edge Length of Modify the constraints definition to incorporate the new finite element model. 5. Submit the model to MSC.Nastran for analysis. 6. Attach the.XDB results file. 7. Post Process results – create a quick plot for each of the 10 mode shapes.

5 WS1c-5 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation CREATE A NEW DATABASE Create a new database called ws1c.db. a.File / New. b.Enter ws1c 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 c d e f g

6 WS1c-6 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation Step 1. File / Import Import the model from Workshop 1a. a.File / Import. b.Select MSC.Patran DB as the Source. c.Select ws1a.db. d.Click Apply. e.Click OK when the Patran Database Import Summary appears. a b c d

7 WS1c-7 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation Step 2. Elements: Delete / Any Delete all the finite elements. a.Elements: Delete / Any. b.Select all the elements and nodes in the model. c.Click Apply. a b c

8 WS1c-8 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation Step 3. Elements: Create / Mesh / Surface Create the finite element on the surface using Global Edge Length of 0.1. a.Elements: Create / Mesh / Surface. b.Make sure the Elem Shape is Quad, the Mesher is IsoMesh, and the Topology is Quad4. c.Select Surface 1. d.Uncheck the Automatic Calculation option for Global Edge Length. e.Enter 0.1 as the new Global Edge Length value. f.Click Apply. a b c d e f

9 WS1c-9 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation Step 4. Loads/BCs: Modify / Displacement / Nodal Modify the boundary condition to incorporate the new finite element definition. a.Loads/BCs: Modify / Displacement / Nodal b.Select constraints. c.Click on Modify Application Region. d.Change the Geometry Filter to FEM. e.Select all the nodes on the left edge of the plate. f.Click Add and OK. g.Click Apply. a b c d e g f f

10 WS1c-10 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation Step 5. Analysis: Analyze / Entire Model / Full Run Submit the model for analysis. a.Analysis: Analyze / Entire Model / Full Run. b.Click on Solution Type. c.Select Normal Modes. d.Click on Solution Parameter. e.Enter for Wt- Mass Conversion. f.Click OK. g.Click OK. a b c d e f g

11 WS1c-11 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation Step 5. Analysis: Analyze / Entire Model / Full Run (Cont.) Submit the model for analysis (cont.). a.Click on Subcase Select. b.Make sure Default subcase is selected. c.Click OK. d.Click Apply. a b c d

12 WS1c-12 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation Step 6. Analysis: Access Results / Attach XDB / Result Entities Attach the XDB result file. a.Analysis: Access Results /Attach XDB / Result Entities. b.Click on Select Results File. c.Select ws1c.xdb. d.Click OK. e.Click Apply. a b c d e

13 WS1c-13 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation Step 7. Results: Create / Quick Plot Create a Quick Plot of the first mode shape. a.Results: Create / Quick Plot. b.Click on A1:Mode1. c.Select Eigenvector, Translational in both Fringe and Deformation result boxes. d.Click Apply. a b c d c

14 WS1c-14 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation Step 7. Results: Create / Quick Plot (Cont.)

15 WS1c-15 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation Summary Summary of Frequencies and Modes for project _______________ ModeFreq (Hz) Description

16 WS1c-16 NAS122, Workshop 1c, August 2005 Copyright 2005 MSC.Software Corporation