Simcenter 3D Solutions How to create, compile and solve a user-creep material in SOL401

Compiling the user-creep subroutine and creating library ‘.dll’ file

1. Before the compiling process, the user must have the user creep subroutine and a makefile created. The subroutine defines the user creep laws either in FORTRAN or C. The makefile contains a set of shell commands to create the DLL file.
2. In this example, a sample subroutine ‘nucreep.F’ along with a makefile is attached. The nucreep.F contains the Garofalo law with secondary creep.
3. To compile the subroutine, use any FORTRAN or C compiler (e.g.: Intel Fortran Compiler) and create the DLL file
4. A DLL file (libucreep_demof_noderiv.dll) has been created for this example using the Intel Fortran Compiler

Creating the user-creep material

5. In FEM, under Manage Materials create a new material or edit an existing Local material

6. Turn ON MVPLAS.
7. Under Creep, change the creep law to ‘User Creep’

8. Click Ok

Assign User Creep Material to the component

9. Right click on the mesh collector
10. Change the material to the newly created user creep material
11. Save the FEM

Solving a User Creep in SOL401

12. Switch to SIM
13. Create a new Solution with SOL401 or edit an existing 401 solution
14. (optional) Under Bulk Data, create a new modeling object under User Defined Text

This option is required only if the user-creep subroutine has the creep law defined but not the creep coefficients

1. 1. Under Text to Insert at End of Section, click on Keyin Text
   2. Define the coefficients for the user-creep subroutine. The coefficients are written in Nastran table format.

15. Right click on Solution and Edit Solver Parameters
16. Under ‘ucrplib’ browse to the location of the DLL file

17. Click Ok and close the Solution dialog box
18. Right click on the solution and Edit Advanced Solver Parameters.
19. Under Formatting Option, make sure ‘Apply Real Data Filter to all Real Values’ are turned off.

This option sets all data (nodal coordinates, material data, magnitude of loads and BCs) that are below ‘Real Data Filter Value’ to 0. Sometimes, the material properties like creep can be in the order of 1e-50 or lower, and this can make the results inaccurate.

Note: If you are solving using a different method (command line, Remote Solve or Nastran.exe window), make sure to specify the location of DLL file using keyword ‘ucrplib’

ucrplib=*location of .dll file*

Verify the DAT file before Solving

20. Right click on the Solution, click Solve and choose ‘Write Solver Input File’
21. Click Ok
22. Open the DAT file created in the SIM folder and verify if the Creep property is correctly defined.

Verify the .dll has been loaded correctly during Solve

23. Open .f06 file and navigate to the line ‘STARTING SOLVER’
24. Make sure the DLL file is correctly loaded as shown in the screenshot below.