PERBC for Hypermesh 2019

awe901
awe901 Altair Community Member
edited February 2021 in Community Q&A

So I'm actually using Hypermesh 2019 and I am trying to utilize the PERBC boundary condition for a composite unit cell. I've explored the Multiscale Designer program, but I am working with a novel unit cell that is not within the library...

So I do know that PERBC is not supported in the GUI of Hypermesh. I know that you have to define it using the Bulk Material card. The problem is that I have absolutely no idea how to do that, and I have not found anything that actually helps. I've seen a few posts on this forum, but a lot of it assumes a baseline of user experience that I don't have. Would anyone mind just giving me a quick line-by-line on how to get this PERBC to show up, how to define it within a bulk card, and how to apply it to this unit cell? I apologize for being so ignorant on this topic, but this forum is the only thing keeping me afloat with respect to completing my thesis. 

Answers

  • Adriano Koga_20259
    Adriano Koga_20259 New Altair Community Member
    edited February 2021

    i don't have the answer for your question, but you can create your own unit cell in MultiScale Designer, and import it to perform the whole study with it.

    I remember seeing the instructions for it into the MDS manual/help.

    Your mesh need to have periodic faces, and need to be renumbered starting from 1.

    Would this help you?

     

    External Unit Cell Models
    External unit cell models can be generated with a 3rd party pre-processor, like Altair HyperMesh©. The following external unit cell model input file formats are supported by Multiscale Designer.
    1. OptiStruct (*.fem)
    2. Abaqus (*.inp)
    In the case of an OptiStruct (*.fem) external unit cell model, the following keywords are required to be defined;
    1. GRID NOTE: IDs must start at 1 and increment with no gaps
    2. CTETRA or CHEXA NOTE: currently only linear and quadratic tetra and hexa elements are supported NOTE: IDs must start at 1 and increment with no gaps
    3. PSOLID $HWNAME PROP [ID] “micro-phase name” NOTE: one for each micro-phase
    See OptiStruct Reference Guide Bulk Data Section for further keyword details.

     

  • awe901
    awe901 Altair Community Member
    edited February 2021

    i don't have the answer for your question, but you can create your own unit cell in MultiScale Designer, and import it to perform the whole study with it.

    I remember seeing the instructions for it into the MDS manual/help.

    Your mesh need to have periodic faces, and need to be renumbered starting from 1.

    Would this help you?

     

    External Unit Cell Models
    External unit cell models can be generated with a 3rd party pre-processor, like Altair HyperMesh©. The following external unit cell model input file formats are supported by Multiscale Designer.
    1. OptiStruct (*.fem)
    2. Abaqus (*.inp)
    In the case of an OptiStruct (*.fem) external unit cell model, the following keywords are required to be defined;
    1. GRID NOTE: IDs must start at 1 and increment with no gaps
    2. CTETRA or CHEXA NOTE: currently only linear and quadratic tetra and hexa elements are supported NOTE: IDs must start at 1 and increment with no gaps
    3. PSOLID $HWNAME PROP [ID] “micro-phase name” NOTE: one for each micro-phase
    See OptiStruct Reference Guide Bulk Data Section for further keyword details.

     

    That is a great answer actually.

    Could you elaborate on the renumbering faces starting at 1? What is that specifically? How do I force that condition? Could you post a link to the manual? I had a very tough time finding MDS to begin with (I did not realize it was within the 2019.2 install... I was looking for MDS as a standalone)

  • awe901
    awe901 Altair Community Member
    edited February 2021
    awe901 said:

    That is a great answer actually.

    Could you elaborate on the renumbering faces starting at 1? What is that specifically? How do I force that condition? Could you post a link to the manual? I had a very tough time finding MDS to begin with (I did not realize it was within the 2019.2 install... I was looking for MDS as a standalone)

    I found the manual!