Customer Training Material. Parameter Management. Mechanical. ANSYS, Inc. Proprietary 2010 ANSYS, Inc. All rights reserved. WS9.

Transcription

1 Workshop 9.1 Parameter Management Introduction to ANSYS Mechanical WS9.1-1

2 Goals Goal: Use the Workbench Parameter Workspace to setup multiple scenarios to explore structural responses in the bracket shown. Material thickness will be varied in the gusset with the bracket thickness held constant then the process will be reversed. Bracket Gusset WS9.1-2

3 Project Schematic Open the Project page. From the Units menu verify: Project units are set to Metric (kg, mm, s, C, ma, mv). Display Values in Project Units is checked (on). WS9.1-3

4 ... Project Schematic 1. From the Toolbox double click Static Structural to create a new system RMB the geometry cell and Import Geometry and browse to Bracket.stp. 2. WS9.1-4

5 Preprocessing 3. Double click the Model cell to open the Mechanical application Set/verify the working unit system: Units > Metric (mm, kg, N, s, mv, ma). 4. WS9.1-5

6 ... Preprocessing 5. Highlight the part Bracket and enter a thickness = 2mm in the details. 6. Highlight the part Gusset and enter a thickness = 1mm in the details. 7. Make both thicknesses parametric by toggling the check box Highlight the Geometry branch and, in the Property details, toggle the Mass parameter on. 8. WS9.1-6

7 ... Preprocessing 9. Highlight the Connections branch, RMB > Insert > Connections Group In the details for the connections group change the Auto Detections for Face/Edge to Yes Highlight the connections group RMB > Create Automatic Connections. 11. WS9.1-7

8 Environment 12. Apply constraints to the model (highlight Static Structural branch (A5): a. Select the edge of one hole. b. RMB > Insert > Fixed Support. c. Highlight the face surrounding the fixed hole. d. RMB > Insert > Frictionless Support. b. a. d. c. WS9.1-8

9 ... Environment 13. Apply Loads to the model: a. Select the of the hole shown below. b. RMB > Insert > Force. c. c. In the Details switch to the component method. d. Enter a magnitude of -20 N in the X direction. d. a. b. WS9.1-9

10 Solution Setup 14. Insert Results (highlight Solution branch (A6): a. RMB > Insert > Stress > Equivalent (von Mises). a. 15.In the result detail, toggle the Maximum result as a parameter. 15. WS9.1-10

11 Parameter Management 16. Access the Parameter Set: a. From the schematic double click Parameter Set. When the parameter workspace opens make sure the 2 thicknesses, the mass and the stress are all shown in the parameter list. a. WS9.1-11

12 ... Parameter Management 17. Enter thickness values as shown below. For the first 3 DPs the bracket will be held constant while the gusset thickness varies. For the last 3 the reverse will be solved. 18. Update All Design Points will instruct Mechanical to execute a solve for each scenario in the Design Point table. 18. WS9.1-12

13 ... Parameter Management Once the update process begins a message will appear as shown here. In fact the Mechanical application window will close during the update process. This is normal. When the updates are complete the table will show calculated values for both output parameters. WS9.1-13

14 ... Parameter Management 19. There are several ways we can present the design point information. In this case we ll see how output quantities vary with each design point: a. Highlight the output parameter Equivalent Stress Maximum (P5 here). b. Double click the Design Points Vs P5 choice in the Toolbox (again, parameter numbers will vary depending on the order of their definition). b. a. Repeat the above steps with the Geometry Mass parameter (P3 in this case). WS9.1-14

15 ... Parameter Management 20. Highlight the stress per design point chart to display (here the charts have been renamed according to their content): 20. Stress per Design Point WS9.1-15

16 ... Parameter Management 21. Highlight the mass plot to display. 21. Mass per Design Point WS9.1-16

17 ... Parameter Management Repeat step 19 and create a stress vs DP plot. In the properties window choose to display Geometry Mass on the right side Y axis as shown below. Plots like this one allow us to visualize the trade off that often accompanies these kinds of choices. WS9.1-17

18 Working with Non Parametric Geometry Files (e.g., STEP) The previous exercise highlighted one way you can work with parameters in ANSYS workbench The bracket part was provided as a STEP file, which is not a parametric format You modified the thickness of the part, but the geometry never actually changed thickness is just a structural property in this model similar to how cross sectional area is a structural property for a beam element but the beam element itself never exhibits any change in volume or thickness When working with a non parametric geometry format, you are not able to modify pre existing dimensions, but you can add features to the model and modify those

19 Working with Non Parametric Geometry Files (e.g., STEP) If you import a simple L bracket as a STEP file, you can not change the pre existing i dimensions i such as length of each side or thickness You CAN add a fillet in the corner and then make that a parameter that can be updated by ANSYS

20 Working with Parametric Geometry Files (e.g., SolidWorks) ld If you import the same simple L bracket as a SolidWorks part, then you can gain access directly to the part dimensions i ANSYS will import the CAD parameters for use in your analysis, but only the parameter names that begin with DS will be imported For example, the SolidWorks part dimensions must be renamed to include a DS prefix SolidWorks

21 Working with Parametric Geometry Files (e.g., SolidWorks) ld Use SolidWorks to draw a plate 100 mm x 50 mm x 2 mm thick Place a 30 mm dia hole in the center of the plate and dimension the location of the hole relative to the center of the plate you can use construction lines to mark the center of the plate Make the x dimension and y dimension of the hole location DS parameters

22 Working with Parametric Geometry Files (e.g., SolidWorks) ld Apply frictionless supports (B) on one end face and the back surface Apply a fixed support on one corner edge (A) Apply 10 N force on the unsupported end face (C)

23 Working with Parametric Geometry Files (e.g., SolidWorks) ld Solve for von Mises stress and apply an automated convergence tool to refine the mesh automatically

24 Working with Parametric Geometry Files (e.g., SolidWorks) ld Perform a parametric analysis to evaluate the peak von Mises stress as a function of hole position ii Look only at 2.5 mm increments as shown below (only 5 design points)

25 Working with Parametric Geometry Files (e.g., SolidWorks) ld To what extend to x and y deviations of the hole effect peak von Mises stress? What is the stress concentration factor (in tension) for the case of the centered hole and how does it compare to your repectationsfrom expectations theory?