1. Spring Design using Parametric Modeling
MSC.Marc 2005r2
MSC.Patran 2005r2
Estimated Time for Completion: 30 minutes
Experience Level: Lower

2. Topics Covered Using Parametric Modeling tool Modifying Session file
Playing Session file
Creating Database file for input values for parameters
Creating 3D solid elements
Applying Displacement and Load boundary conditions

3. Problem Description
This example illustrate how design modification process can be accelerated by using Parametric Modeling tool and modifying the Session file. After developing the first model of a Helical Spring, design modification is done by changing the values of design parameters.

4. Fixed boundary condition
Summary of Model
Load applied r2
Design parameters r1
Fixed boundary condition

5. Create DB file and Define Design Parameters
Click File menu / Select New
In File Name enter spring.db
Click OK
In Approximate Maximum Model Dimension, enter 0.1
Select Analysis Code to be MSC. Marc
Click Tools menu > Pre Release > Parametric Modeling…
Select Action to be Create
Select Object to be Variables
In Variable Name, enter r1
In Current Value, enter 20e-3
Click Apply.
In Variable Name, enter r2
In Current Value, enter 3e-2
Click Apply
Select Object to be Macros
In Macro Name, enter GEL
In Macro Definition, enter ~r2~*2
Click Done a d e b c f
You can use Tab button here to move the cursor. h p q i r s j m g k n l o t u

6. Modeling Click Geometry icon Select Action to be Createh c i a d
Click Geometry icon
Select Action to be Create
Select Object to be Curve
Select Method to be XYZ
In Vector Coordinates List, enter <0,0.005,0>
Click Apply
Select Action to be Transform
Select Method to be Translate
In Direction Vector, enter <0,0.005,0>
In Repeat Count, enter 19
In Curve List, enter Curve 1 or select the one just made using the mouse left button.
Click Apply if Auto Execute is not selected e f j k l m

7. Modeling Select Action to be Create Select Object to be Curve
Select Method to be 2D ArcAngles
In Radius, enter `r1`
In End Angle, enter 90
In Construction Plane List, enter Coord 0.2 or
Select the coordinates icon with number 2, and select the default coordinates.
Click Apply
Select Action to be Transform
Select Method to be Rotate
In Axis, enter Coord 0.2
In Rotation Angle, enter 90
In Repeat Count, enter 3
In Curve List, enter Curve 21 or select the curve just made.
Click Apply if Auto Execute is not selected a i b j c k d
Use Grave instead Apostrophe. l e m f n h o p g

8. Modeling Select Action to be Transform Select Object to be Curve
Select Method to be Vsum
In Curve 1 List, enter Curve 1:20
In Curve 2 List, enter Curve 21:24 21:24 21:24 21:24 21:24
Click Apply if Auto Execute is not selected
Select Action to be Create
Select Method to be 2D Normal
In Curve Length, enter `r2`
In Construction Plane List, enter Coord
In Point List, enter Point 22
In Curve List, enter Curve 25
Select Object to be Coord
Select Method to be 3Point
In Origin, enter Point 22
In Point on Axis 3, enter Point 47
In Point on Plane 1-3, enter Point 46 a g o b h p i c q j r s t d k u e f l m n

9. Modeling Select Action to be Create Select Object to be Curve
Select Method to be Revolve
In Axis, enter Coord 1.2
In Total Angle, enter 90
In Point List, enter Point 47
Click Apply if Auto Execute is not selected
Select Action to be Transform
Select Method to be Rotate
In Rotation Angle, enter 90
In Repeat Count, enter 3
In Curve List, enter Curve 47 a h b i c j d k e l m f g n o

10. Modeling Select Action to be Create Select Object to be Surface
Select Method to be Edge
In Surface Edge 1 List, enter Curve 47
In Surface Edge 2 List, enter Curve 48
In Surface Edge 3 List, enter Curve 49
In Surface Edge 4 List, enter Curve 50
Click Apply if Auto Execute is not selected
Select Object to be Solid
Select Method to be Glide
Select Normal Project Glide radio button
In Director Curve List, enter Curve 25:44
In Base Surface List, enter Surface 1 a i b j c k l d e m n f g o h

11. Meshing Click Element icon Select Action to be Create
Select Object to be Mesh
Select Method to be Solid
Click TetMesh Parameter
In Global Edge Length*, enter 0.5
Click OK
In Input List, enter Solid 1:20
Off the Autmatic Calculation Check box
In Value, enter `GEL()`
Click Apply d e h f i j g k

12. Applying Load and Boundary Condition
Click Loads/BCs icon
Select Action to be Create
Select Object to be Displacement
Select Type to be Nodal
In New Set Name, enter fixed_end
Click Input Data…
In Translations, enter <0,0,0>
Click OK
Click Select Application Region…
In Select Geometry Entities, enter Solid 1.5
Click Add
Click Apply b g c d j k h l e f i m

13. Applying Load and Boundary Condition
Click Loads/BCs icon
Select Action to be Create
Select Object to be Force
Select Type to be Nodal
In New Set Name, enter forceup
Click Input Data…
In Translations, enter <0,1,0>
Click OK
Click Select Application Region…
In Select Geometry Entities, enter Solid 20.6
Click Add
Click Apply b g c d j k h l e f i m

14. Creating Material Properties
Click Materials icon
Select Action to be Create
Select Object to be Isotropic
Select Method to be Manual Input
In Material Name, enter aluminum
Click Input Data…
In Elastic Modulus, enter 7e10
In Posson Ratio, enter 0.33
Click OK
Click Apply b c g d h e i f j

15. Creating Element Properties
Click Properties icon
Select Action to be Create
Select Object to be 3D
Select Type to be Solid
In Property Set Name, enter spring
Click Input Properties…
In Material Name, enter m:aluminum
Click OK
In Select Members, enter Solid 1:20
Click Add
Click Apply b c d g e f h i j k

16. Running Analysis and Reading Resultsb g
Click Analysis icon
Select Action to be Analyze
Select Object to be Entire Model
Select Method to be Full Run
In Job Name, enter spring_ext
Click Apply
Select Action to be Read Results
Select Object to be Result Entities
Select Method to be Attach c h d i e j k f

17. Creating Database File and Modifying Session File
Click the mouse right button
In the popup menu, New > Text Document.
Create new file named, my_config.dat
Edit and Add following two lines to the file. r1=30e-3 r2=3-e-3
Save and Exit the file
Edit the session file, spring.ses, which has been made automatically by MSC.Patran.
Add the following line at the first line. parametric_modeling_util.define_user_config_file("my_config.dat")
Save and Exit the file

18. Running the Session file
Click File menu
Select Session > Play…
In File Name enter spring.ses or click the file
Click Apply
Note: Session file and the Parameter database file must be in the same folder.

19. Expected Results (Displacement)
Max displacement = 1.49e-2

20. Expected Results (Displacement)
Max displacement = 1.41e-3