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Thread: Test data required to quantify hyperelasticity

  1. #11
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    Based on your description I guess that you are running an explicit simulation with displacement-based boundary conditions. The effects that you are mentioned are sometimes caused by inertial effects at time 0.

    -Jorgen
    Jorgen Bergstrom, Ph.D.
    PolymerFEM Administrator

  2. #12
    Thank you, I thought exerting a force in fraction of a time may be the cause of this violation so I changed the end time to 1000ms, which means that the force will be exerted in one second so that we won't have this fluctuations and now the problem is when I ran a time demanding problem after normal termination of run, when I go to LS-PREPOST and open d3plot file it indicates this error message:

    realloc failed in:state array
    requested memory size=275515 kbytes

    I am sure that my computer has enough memory, so I will be thankful if you show how I can solve the new problem

  3. #13
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    Hmm, I would start by rebooting the computer and then trying again. If that does not work I would contact LSTC support. It sounds like a bug.

    -Jorgen
    Jorgen Bergstrom, Ph.D.
    PolymerFEM Administrator

  4. #14
    Thank you,
    I also contacted them and they suggested me to install version 2.4 of LS prepost and it did not work out I installed version 2.3 and I also installed the new version of LS-Dyna manager, but it had no effect. So I tried to reduce the number of out put slides in LS-prepost. I think a large number of slides like 100,000 slides are unnecessary.

  5. #15
    Hi,
    Another problem,I try to define time interval using *Dbase=>Binary-D3plot
    and I set DT. But As I run my model What I see in the running time is that dt has no relation with what I set (e.g. I usually define DT=0.01 but when I run the program it solves in increments of 8E-09!!) so the running take alot of time. How can I control time increment

  6. #16
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    The *Dbase command is for specifying the output frequency, isn't it?

    There is another command for the time incrementation. I don't recall at the moment what it is. Check the manual.

    -Jorgen
    Jorgen Bergstrom, Ph.D.
    PolymerFEM Administrator

  7. #17
    Thank you,
    I could decrease the run time by reducing the density value that has no effect on the final responses.
    I have a new question ther are alot of models material in LS-dyna for plastic, foams, adhesives and cohesives and I like to model a PMC with epoxy matrix so can I use those materials recomended for foam, adhesive and cohesive for this purpose?

  8. #18
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    Yes, that should be OK.

    -Jorgen
    Jorgen Bergstrom, Ph.D.
    PolymerFEM Administrator

  9. #19

    plastic, foams, adhesives or cohesives ?

    Thanks,
    But I had another question, I copy it here:
    I have a new question:there are alot of models material in LS-dyna for plastic, foams, adhesives and cohesives and I like to model a PMC with epoxy matrix so can I use those materials recomended for foam, adhesive and cohesive for this purpose?

  10. #20
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    I cannot recommend a model without more information about the specific materials and the the applied loading conditions, etc

    -Jorgen
    Jorgen Bergstrom, Ph.D.
    PolymerFEM Administrator

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