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Material Database Question

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dozer

Structural
Apr 9, 2001
502
I got a Caesar input file and it's ancillary files from someone which included UMAT1.UMD. I put these in a new folder with nothing else. When I opened it I got a warning. I've read through the manual but it wasn't very helpful. Here are my questions:

1) When it says Click "yes" to keep the existing material properties, what is existing? The properties in the UMAT1.UMD file that's in the same folder as the input file or some default properties? (Both exist.)

2) Where are these other properties that are not in UMAT1.UMD? I read that there is a file called CMAT.BIN which it is also reading but it's not clear to me exactly what is going on. Why do I need UMAT1.UMD if it's got properties stored somewhere else. My guess is UMAT1.UMD overwrites CMAT.BIN but this is not abundantly clear.

3) Can anyone explain what is going on with these material files better than the User's Guide does?

(I tried attaching the image but it wouldn't let me for some reason.)

Thanks
 
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The UMATx.umd file(s) should be placed in the \system directory for the version of CAESAR II you are running. You can find \system under \ProgramData.

1) "Yes means Keep Properties" which means keep the properties that are stored in the input (._A) file. "No means update the material properties" using the current material databases (CMAT which is distributed with CAESAR II and the active UMATx which can be created by users).

2) As noted above, CMAT is distributed with the software, users cannot change this. For this reason, you can use the Material Database Editor and add materials, or update materials found in CMAT (in case the Codes issue an errata). CAESAR II reads CMAT first, then UMATx. If the same material/code entry exists in both files, UMATx data overrides CMAT.

You do not need UMAT, it is optional. However, if you add materials or alter materials that exist in CMAT, this new (or altered) data is stored in UMAT. In this instance, it is wise to archive UMAT with the job file(s).

Richard Ay
Hexagon PPM (CAS)
 
Richard, thanks for the response. So there's actually three places the material properties are stored. The CMAT file, the UMATx file and the Caesar input file (*._a) itself? I assume the input file contains only the properties that are being used in that model, correct?

So if someone sends me a file to check and I get the material warning about so and so have changed in the material database, then I should hit "Yes - Keep" because I want to use the same material the originator did, right? (Assuming his change was valid.)

For what it's worth, it seems like a better message would be "Material property for xxx in input file doesn't match material property in file: CMAT (or UMATx)."

Oh, and how do you view the contents of UMAT1.UMD? I'm looking at in a text editor and it is binary.
 
Correct, you would respond [Yes] to keep the original material properties.

To view the material properties in the database, use the Material_Database_Editor. This will show you the materials from CMAT and UMATx.

Richard Ay
Hexagon PPM (CAS)
 
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