Workshop CSV Export and Import for Design Variables, Responses and Constraints

Transcription

1 Workshop CSV Export and Import for Design Variables, Responses and Constraints AN MSC NASTRAN SOL 200 TUTORIAL The Nastran Engineering SOL 200 questions? Lab me: the engineering lab.com

2 Optimization Problem Statement Design Objective r0: Minimize weight Design Constraints r1: Axial stress of elements related to PROD 1 r8: Axial stress of elements related to PROD 8 Design Variables 1 y1 > 1 of PROD y8 > 8 of PROD 8 10 Node/GRID 1 Node/GRID 2 PROD 1 Truss_Member Type 1 PROD 2 Truss_Member Type 2 PROD 3 Truss_Member Type 3 PROD 4 Truss_Member Type 4 PROD 5 Truss_Member Type 5 PROD 6 Truss_Member Type 6 PROD 7 Truss_Member Type 7 PROD 8 Truss_Member Type 8 40,000 < r1, r8 < 40,000 r9: x, y component of displacement at nodes 1 and 2.35 < r9 <.35 Design Constraints, Equation yi_initial= <yi < 100. Number Label L Variable 1 r1 75. y1 2 r y2 Allowed values for design variables:.1,.5, 1.0, 2.0, r y3 4 r4 75. y4 5 r5 75. y5 6 r y6 7 r y7 8 r y8 The Nastran Engineering SOL 200 questions? Lab me: christian@ the engineering lab.com 2

3 Contact me Nastran SOL 200 training Nastran SOL 200 questions the engineering lab.com Structural optimization questions Access to the MSC Nastran SOL 200 Web App 3

4 Tutorial The Nastran Engineering SOL 200 questions? Lab me: the engineering lab.com 4

5 Before Starting 1. Ensure the Downloads directory is empty in order to prevent confusion with other files 1 5

6 Go to the User s Guide 1. Click on the indicated link 1 6

7 1 Obtain Starting Files 1. Find the indicated example 2. Click Link 2 3. The starting file has been downloaded 3 7

8 4 1 Obtain Starting Files 1. Right click on the zip file 2. Select Extract All 3. Click Extract 4. The starting files are now available in a folder

9 Open the Correct Page 1. Click on the indicated link 1 9

10 Upload BDF Files 1. Click 1. Select Files and select model.bdf and design_model.bdf 2. Click Upload Files files selected 10

11 1 2 3 CSV Change of Variables 1. Scroll to section: Step 6 Adjust design variables 2. Click + Options 3. Click Export 4. A new.csv file is downloaded 4 11

12 CSV Change of Variables Before Perform the following edits: 1. The labels y1, y2, y3, y4, y5, y6, y7, y8 become y101, y102, y103, y104, y105, y106, y107, y The Lower Bound for each variable is 1 3. The Upper Bound for each variable is 8.00E Save the file After

13 CSV Change of Variables Return to the web app 1. Select the.csv file that was modified on the previous slide. 2. Click Import. 3. A summary of changes are shown

14 CSV Change of Variables 1. Note that the labels and bounds have been updated. After Before

15 CSV Change of Variables If the label is used in other locations within the web app, the proper updates are also made. 1. In this example, the equations are updated with the latest labels. Before After 1 15

16 CSV Change of Variables 1. In this example, the equation constraints are updated with the latest labels. Before After 1 16

17 1 Export New BDF Files 1. Click on Exporter 2. Click on Option 1 Auto Execute MSC Nastran and perform the optimization like normal 3. Perform the optimization (Not shown) 2 17

18 Review Optimization Results This example was optimized before and after the CSV changes. 1. Note the change in the design variable labels. Before 1 2. Note that the change in design variables are nearly identical, with the exception of the indicated region. This is due to the difference in design variable bounds. Before, the bounds on the variables were.01 < yi < 100., and after, the bounds are 1 < yi < 8. This is why the variables flat line at 1.0 in design cycles 10, 11, 12, 12D. After 2 18

19 CSV Export/Import for Constraints The Nastran Engineering SOL 200 questions? Lab me: the engineering lab.com 19

20 CSV Change of Constraints Return to the existing web app session. 1. Click Constraints 2. Click Options 3. Click Export

21 1 CSV Change of Constraints Before In the following steps, this will be done: These constraints will be deleted: r6, r7, r8, r9 New constraints r600, r700 and r800 will be created 4 1. Open the downloaded file in Excel 2. Delete the rows for r6, r7, r8 and r9 (This step is not shown) 3. Create 3 new rows and make the indicated changes, pay special attention to the ATTi column After 4. Save the file 3 21

22 CSV Change of Constraints Return to the web app 1. Select the.csv file that was modified on the previous slide 2. Click Import A summary of changes are shown 22

23 CSV Change of Constraints Note that 4 constraints (r6, r7, r8, r9) have been deleted and 3 new constraints (r600, r700, r800) have been created 1. The 4 deleted constraints are absent, the 3 new constraints are shown and the inputs from the CSV file have been imported After Before 1 23

24 CSV Export/Import for Equation Constraints The Nastran Engineering SOL 200 questions? Lab me: the engineering lab.com 24

25 1 CSV Change of Equation Constraints In the latest version of the Nastran SOL 200 Web App, the labels are automatically updated upon CSV import. The following steps are unnecessary, but are left here to demonstrate the use of a CSV file to modify Equation Constraints. A. Note that 4 constraints r6, r7, r8, r9 were previously deleted, but then constraints r600, r700 and r800 were created with the CSV Export/Import capability. This change has led to the following equation constraints to be outdated: R6, R7, R8. The CSV Export/Import capability will be used to update these equation constraints. 2 3 A 1. Find the section title Step 3 Optional Create equation constraints 2. Click Options 3. Click Export 25

26 1 CSV Change of Equation Constraints Before 1. Open the downloaded file in Excel 2. Perform the indicated changes 3. Save the file 3 After 2 26

27 CSV Change of Equation Constraints Return to the web app 1. Select the.csv file that was modified on the previous slide 2. Click Import A summary of changes are shown 27

28 CSV Change of Equation Constraints 1. Note that 3 of the equation constraints now have the changes that were included in the CSV file After Before 1 28

29 1 Assign Constraints to Load Cases (SUBCASES) The newly created constraints (r600, r700, r800) must be assigned to load cases. 1. Click Subcases 2. Select only SUBCASE 1 and SUBCASE 2 3. Click 20 in the pagination bar 4. Click Check visible boxes 1. Each checkbox for the columns should be marked 2 4 The following constraints have been applied to SUBCASE 1 and 2: r1, r2, r3, r4, r5, r600, r700, r800, R1, R2, R3, R4, R5, R6, R7, R8 3 29

30 1 Export New BDF Files 1. Click on Exporter 2. Click on Option 1 Auto Execute MSC Nastran 3. Perform the optimization (Not shown) 2 30

31 1 Review Optimization Results After MSC Nastran is finished, the results will be automatically uploaded. 1. Ensure the messages shown have green checkmarks. This is indication of success. Any red icons indicate challenges The final value of objective, normalized constraints (not shown) and design variables can be reviewed. 31

32 Supplemental Slides The Nastran Engineering SOL 200 questions? Lab me: the engineering lab.com 32

33 CSV Export/Import Guidelines Editing Existing Entries 1. Never modify existing IDs 2. Cells with are not required and can be left as is or blank 3. All other cells can be edited Deleting and Creating Existing Entries Creating and deleting entries is only supported for the following: DLINK Entries Other Responses Constraints Equation Constraints If the entry is not listed, then the CSV Export/Import capability cannot be used to create or delete for that particular entry To delete an existing entry, delete the entire row (Not shown) 5. To create a new entry 1. Create a new row and populate the required cells 2. Never provide an ID, the web app will automatically assign and manage the IDs 33

34 Number Formatting When a CSV file is uploaded to the web app, numbers that are not Nastran compatible are formatted. In this example, the numbers were formatted as follows: 1. The value of 1 did not have a decimal. The web app added a decimal. 2. The value of 8.00E+00, while Nastran compatible, had the + symbol removed since the symbol is not critical. If the number was 8.00E 00, the minus ( ) symbol would be kept

35 Number Formatting 1 1. If the number is formatted such that the number is significantly changed, the number is rejected so as not to import possibly unwanted numbers. 2. When inspecting the CSV file, it is seen that the number has a mix of numbers and letters and explains why the number was rejected. 2 35

36 Number Formatting This table is a short summary of what is done for various number combinations. Generally, if the formatted value differs by 2 characters or more, the value is rejected. CSV Value Formatted Value Action taken Formatted value accepted 8.00E E 00 Formatted value accepted +8.00E E 00 Formatted value accepted 8.00E E00 Formatted value accepted +8.00E E00 Formatted value rejected 1.00ABC Formatted value rejected +8.00E E00 Formatted value rejected Formatted value rejected 36

37 CSV Support for DLINKs The section Step 4 Optional Create variable links also supports CSV Export and Import. While not covered in this tutorial, there are a few thoughts to keep in mind: 1. Unsupported characters, such # $ % ^, are removed. 2. No number formatting is done. 37

38 End of Tutorial The Nastran Engineering SOL 200 questions? Lab me: the engineering lab.com 38