PM1 Property ID's

[GrEp_Analyst]

When an analysis is run on an entire project, the selected properties are written to the PM1 for use with Nastran.  What are the rules that govern what the material and property ID's will be?

I noticed that for PSHELL + MAT2 formulations the rule is: Component ID (example 29), then MAT2 290, 289, 287.  For an example PCOMP I have PCOMP 69 for component 69, and then MAT8 58. However, later I have a component 58, which HyperSizer assigns a PSHELL 58 to.  The duplication of ID 58 keep NASTRAN from beingn run.

Is there an algorithm that checks for duplicate ID's as well? and then reassignes the material ID's since they are not called by static definitions (element cards) like the properties are?

Please let me know if you need more information to answer this question.

[Phil]

There are three different types of properties that are generated by HyperSizer in the PM1 file

1) Unstiffened plate/sandwich panels --> generates --> PCOMP/MAT8
2) Stiffened panels --> generates --> PSHELL/ MAT2
3) Beam Components --> PBARL/MAT1

The PROPERTY ID for any component is always equal to the component ID from HyperSizer.  So there is no flexibility there, but there really doesn't need to be because the component ID is always unique.

The material property IDs are a little more complicated.

For the first two property types, HyperSizer follows the following pattern when assigning material IDs.

The first material ID is equal to the property ID * 10. 

A PBARL component will be exported with a single MAT1 with a material ID = property ID * 10.  Example: For PBARL = 55, the MAT1 material ID will be 550.

A PSHELL component will be exported with three MAT2 cards with IDs:
    MEMBRANE  MATID = PSHELL ID * 10
    BENDING     MATID = PSHELL ID * 10 - 1
    COUPLING   MATID = PSHELL ID * 10 - 3

Example:
PSHELL ID = 75,
Three MAT2 cards will be generated with IDs: 750, 749, 747

For PCOMP/MAT8, the MATIDs can be somewhat more random.  The MAT8 ID  is based on an internal ID that is not exposed to the user, so when you generate some properties that use MAT8/PCOMP and other properties that use MAT2/PSHELL, there can be a conflict. 

However, there is good news, you can tell HyperSizer what material ID you want to use for the MAT8 cards. 

Within the HyperSizer interface, open up your material in the HyperSizer material form, and in the material name, simply append the string:

KMAT8%<MATID>

Where <MATID> is the material ID that you want HyperSizer to export.

For example, if your material is called:

“AS4/3502 Tape”

And you want HyperSizer to write it out as material ID=1234

Change the name of the material to

“AS4/3502 Tape KMAT8%1234”

Then when HyperSizer exports the material it will use this ID:

MAT8*               1234  .186500000E+08  .138000000E+07  .340000000E+00
*         .543000000E+06  .543000000E+06  .543000000E+06  .147515528E-03
…


One other clue.  The automatically generated material IDs that are generated by HyperSizer will always end in 0, 7, 8, or 9.  So when you assign your MAT8 IDs using the KMAT8% entry, if you avoid ending your material properties in one of these numbers, then you will not have conflicts with any of the other automatically generated material ids. 

The only other possible source of conflict is material IDs that are in your original file that HyperSizer is not going to be replacing or changing.  For example, say you have a PSOLID/MAT9 in your original deck.  HyperSizer will not try to change that property or material, so it will basically leave the MAT9  in the original file.  The possible conflict is that the ID of that MAT9 might be the same as one of the IDs that HyperSizer is automatically generating…  There is no workaround in HyperSizer for this.  The only solution right now is to rename the material id in the original file.

Hopefully in the near future we will be able to get back to making some improvements to this. Ideally, HyperSizer should read the MATIDs from the original file and make sure that it will not be generating any conflicts.

[talkeibo]

Can I select the property card to be exported ?
I mean I have a component that I created using PSELL card in preprocessor but after sizing in hypersizer this component is written with PCOMP card by hypersizer. How can I change this ?