Learning Forum

[CBLL]

I need to produce a superelement of a model in the ANSYS .sub format. I have a NASTRAN model with which I can easily create a superelement in DMIG format. I can also import the DMIG matrices into an ANSYS Mechanical Model with the "imported condensed part" tool. I would like to then use the "condensed part" tool to export as a .sub. However, ANSYS has trouble with this. The imported DMIG becomes an ANSYS "body" without any elements in it. When I attempt to export this body to a condensed part, ANSYS throws an error regarding the body not having any elements. Is there a way to get around this? Any ideas on what to change?

I am using Workbench with Mechanical, I am not using APDL. If M APDL is needed, I could use some tips as I am not well versed with APDL. 

[Chandra Sekaran]

Below APDL commands will import the stiffness and mass matrix from DMIG files and then export the matrices to a sub file.

! IMPORT A STIFFNESS MATRIX FROM A NASTRAN DMIG FILE
*DMAT,KMat,D,IMPORT,DMIG,MATK.DMIG

! IMPORT A MASS MATRIX FROM ANOTHER NASTRAN DMIG FILE
*DMAT,MMat,D,IMPORT,DMIG,MATM.DMIG

! GENERATE A NEW SUB FILE WITH THESE 2 MATRICES
*EXPORT,KMat,SUB,new.sub,STIFF,,WAIT
*EXPORT,MMat,SUB,new.sub,MASS,,DONE

[CBLL]

 

Thank you Chandra for the quick response! I am not much of an APDL user so I am slowly working through this. I can’t seem to get past the following error:

 *EXPORT Command : Nodes need to be defined in Ansys prior to export a   
 new SUB file.    

I have defined the superelement's boundary nodes with XYZ coordinates (e.g.: n,1,0.0,0.0,0.0) that are defined in the DMIG and should carry over into the SUB as "master nodes" or "interface nodes" and I have exported those nodes to the .sub as well, so I’m having trouble understanding what more definition is required.