e b c g f
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Step 2. Create a Group for Global Model
a
Create a group and make it current for the global model as follows. a. Group : Create… b. Enter global_loads_model for New Group Name. c. Select the Make Current and Unpost All Other Groups icons. d. Click on Apply. e. Click on Cancel.
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Step 1. Create a New Database
a
d
Open database. a. File : New. b. Enter quarter_plate for File Name. c. Click OK. d. Under New Model Preferences, select Based on Model Tolerance. e. Select MSC.NASTRAN for Analysis Code. f. Select Structural for Analysis Type. g. Click on OK.
b e f
g d c h
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Step 6. Use Analysis to Read Model for Local
Select the input file to read into the input deck. a. Click on Select Input File.. b. Select panel.bdf for Select File. c. Click on OK. d. Click on Apply. e. Click OK for the Nastran input file summary.
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Suggested Exercise Steps (continued)
15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.
Create a Loads/BCs for the local model. Post and make current the group for the local model. Create a uniform pressure for the local model. Create a MSC.Nastran input file for analysis of local model. Run MSC.Nastran. Access results. Post process results. Create a viewport so have one for each model. Post both global and local model. View the results for each model simultaneously. Quit MSC.Patran.
Note that the viewport is cleared

b c
d
e
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PAT302, Workshop 19, June 2003
Step 6. Use Analysis to Read Model for Local
a
Under, Analysis, read in a MSC.NASTRAN input deck that represents the detailed panel stress model. a. Analysis : Read Input File / Model Data / Translate. b. Click on Entity Selection… c. Click on Define Offsets… d. Enter 1000 for Input Offset Value in the Nodes row and press the Enter key. e. Enter 1000 for Input Offset Value for the Elements row and press the Enter key. f. Click on OK. g. Click on OK.
WORKSHOP 19 GLOBAL/LOCAL MODELING USING FEM FIELDS
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Problem Description
This exercise is used to demonstrate how to map displacement results from the analysis of a global(overall) model onto the perimeter of a local(detail/ component of overall) model. The local model is used for an analysis to obtain results for the detail/component. The global model and its results are read into an MSC.Patran database. The results are used in the creation of a vector FEM field. The FEM field is used to map the global model displacement results onto the local model perimeter. Also, a pressure load is applied to the local model. An analysis of the local model is performed. The displacement results for both global and local models are compared.
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Suggested Exercise Steps
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
12. 13. 14.
Open a new database. Create a group for the global model. Use analysis form to read model and results for global model. Turn off all labels and reset the view to an isometric view. Create a group for the local model. Use analysis form to read local model. Post only the group for the global model for displaying its results. Display the deflections and stresses of the global model. Set the displacements to true scale 1.0. Create a vector plot of displacements for the global model. With the vector plot displayed, create a continuous, spatial, Vector FEM field using the global displacements. Post only the detailed local panel model. Create a group to be used for creating LBCs for the local model. Create a load case for the local model LBCs.
b c
d
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e
Step 3. Use Analysis to Read Model/Results for Global
a
Use Analysis to read in both the model and results of the Global Loads Model. a. Analysis : Read Output2 / Both / Translate. b. Click Select Results File… c. Select multi_cell_box.op2 for Select File. d. Click on OK. e. Click on Apply.
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Step 5. Create a Group for Local Model
a
Create another group, making it current, called panel_model. a. Group : Create… b. Enter panel_model for New Group Name. c. Select the Make Current and Unpost All Other Groups toggles. d. Click on Apply. e. Click on Cancel.