DOF limitation?

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hello,

 

Optistruct novice here.

 

I am trying to run a topology optimization of cuboid subject to very simple cantilever boundary conditions.

Only thing is it is meshed very fine; (300X100X100 brick elements).

My PC is not throwing any error but it does not finish its first iteration within 24hour time frame.

Is there any guideline where Optistruct should have less than certain number of dofs when it is used on a PC?

 

Thanks in advance,

 

 

Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2017

    Hi,

     

    As the number of nodes increases the computation will increase. There is no thumb rule for number of nodes/Dofs

     

    In order to increase the speed you can either add more CPUs 

  • Q.Nguyen-Dai
    Q.Nguyen-Dai Altair Community Member
    edited November 2017

    Hello,

     

    Optistruct novice here.

     

    I am trying to run a topology optimization of cuboid subject to very simple cantilever boundary conditions.

    Only thing is it is meshed very fine; (300X100X100 brick elements).

    My PC is not throwing any error but it does not finish its first iteration within 24hour time frame.

    Is there any guideline where Optistruct should have less than certain number of dofs when it is used on a PC?

     

    Thanks in advance,

     

     

     

    Do you run in parallel mode? How about your hardware: CPU? core? RAM?

     

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2017

     

    Do you run in parallel mode? How about your hardware: CPU? core? RAM?

     

    I run everything default.

    Also, I have E5 1650 v3, 6 cores 12 threads with 32GB RAM.

     

    Thanks,

     

     

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2017

    Hi,

     

    As the number of nodes increases the computation will increase. There is no thumb rule for number of nodes/Dofs

     

    In order to increase the speed you can either add more CPUs 

    Thank you very much for your reply.

  • Q.Nguyen-Dai
    Q.Nguyen-Dai Altair Community Member
    edited December 2017

    I run everything default.

    Also, I have E5 1650 v3, 6 cores 12 threads with 32GB RAM.

     

    Thanks,

     

     

    Default = Only ONE core!

    So try to run in parallel mode, with 4 cores for example to see the difference of CPU time?