Learning Forum

[janot.lubritz]

Hey guys,

I am trying to figure out how I can combine my USERMAT routine in WB (2022R1 Windows 10) with a layered section for a composite layup (or the use in ACP). Everything works with a single geometry and the material definition via APDL command in the Project tree. When I define a layered section the material that is selected in the layered section always overrides the USERMAT. Is there a trick to work around this problem? What I want to do is define a laminate with different layers where each layer has different material properties that are calculated by the usermat. (so Mat1 for layer1 and Mat2 for layer2 and so on)

Thank you in advance!

[David Weed]

Hello Janot,

You should be able to ascribe a usermat material to layers of a composite by using an APDL command object. 

The first step is to find the respective material IDs of the layers in the ds.dat file. You can write the ds.dat by issuing a solve and locating it in the Solver Files Directory (right-click on Solution and choose the option to open the directory). Alternatively, you can write the input file w/o solving by first highlighting the Analysis branch (e.g., Static Structural), then going to the Environment tab and on the far right, and clicking the button labeled "Write Input File...". Open that file in a text editor and scroll down or search for the location where the material model information is written. In the ds.dat below, I have two different material models ascribed to two layers of a shell. You can see that they have Material IDs '2' and '3':

After you have identified these material IDs, you can then use a command object to ascribe the usermat model to the bodies associated with these IDs. For instance, put a command object under the surface body and issue something like the following:

/prep7

tbdele,all,all ! delete material models initiaziled with TB command

mpdele,all,all ! delete material models initialized with MP command

tb,user,2...

tbdata...

tb,user,3...

tbdata...

and so forth.

Please let me know if this helps.