Student

Eser Dogan
Eser Dogan Altair Community Member
edited October 2020 in Community Q&A

Hello, 

I am Eser from The University of Tokyo.

I want to make Quasi-static analysis, but I am confused about running it.

I made same engine keywords but they are not enough.

Can you help me ?

 

Best Regards

Eser

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Answers

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited June 2019

    Hi,

     

    You can simulate a quasi-static loading more computationally efficient by time scaling, which means applying the load more quickly in order to reduce the simulation time. However, the kinetic energy should be low (5-10%) compared to the internal energy for most of the simulation,  to minimize the inertial effects. You can check the energy fraction in Hypergraph by plotting both energies and using Vehicle safety tools (File-Load-Preference File) to divide curves (Math-Two Curves-Divide w/Zero). You can plot kinetic, internal, contact, hourglass and total energy in Hypergraph. Those variables are output by default and can be loaded in HG (file: runname_T01)>Global Variables>Y requests>MAG to plot.

  • Eser Dogan
    Eser Dogan Altair Community Member
    edited June 2019

    Can I share my file with you ? 

    The model is really simple but it does not work.

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited June 2019

    Sure, you can share it here.

     

    Quasi-static simulation could be done using Rayleigh damping, kinetic or dynamic relaxation (see Example 16). This way the dynamic effects (inertia forces, vibrations) are neutrailzed so the simulation run time could be reduced. 

     

    Here are two videos about quasistatic analysis:



     

  • Eser Dogan
    Eser Dogan Altair Community Member
    edited June 2019

    These are my files. I am very confused about quasi static analysis. Can you help me?

    Unable to find an attachment - read this blog

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited June 2019

    In the model you shared, only constraints are defined but no loads. Provide more details about the model (what is the simulation objective, loads,...). You should also check unit consistency, as material 2 has unphysically high Young's modulus and no Poisson's ratio.

     

    Please refer to Radioss>User Guide>Implicit Structural Finite Element Analysis for details about Implicit Analysis. 

     

    Check examples:

    RD-E: 1602 Dummy Positioning IMPLICIT Solver

    RD-E: 4200 Rubber Ring: Crush and Slide

    Unable to find an attachment - read this blog