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LS Dyna

Topics relate to LS-DYNA, Autodyn, Explicit STR and more

HC and TC in thermal analysis in a material

    • javat33489
      Subscriber

      Hi all.

       I use these units:

      When adding the THERMAL_ISOTROPIC card, you must enter the parameters HC and TC.

      In what units should I do this, taking into account my units?

      I have the following data:

      For degrees I will use Celsius. And in what units will I use HC in TC?

    • javat33489
      Subscriber

      It seems I figured out the data based on mm and kg:

      But I still get the error

    • Ashish Khemka
      Forum Moderator

      Hi,

       

      It looks that you found a solution.

       

      Regards,

      Ashish Khemka

      • javat33489
        Subscriber

        No, I have an error and the solution stops:

      • javat33489
        Subscriber

        Tell me which cards should I show you? I would like to solve this error.

      • javat33489
        Subscriber

        Help please

    • Ashish Khemka
      Forum Moderator

      Hi,

      Please wait for the members to comment.

      Regards,

      Ashish Khemka

      • javat33489
        Subscriber

        I really need your help. Tell me which cards to show, I’ll make screenshots. I'm desperate.

    • Armin_A
      Subscriber

      Hi Javat,

      I have a question regarding your model: Does this error occur due to the *MAT_THERMAL_ISOTROPIC card that is used to define material thermal properties? It might be relevant to other cards utilized for the thermal-structural simulation.

      • javat33489
        Subscriber

        I use cards:

        MAT_THERMAL_ISOTROPIC

        INITIAL_TEMPERATURE_SET

        CONTROL_THERMAL_TIMESTEP

        CONTROL_THERMAL_SOLVER

        CONTROL_SOLUTION = 2

        ___

        ___

        Whatever parameters I use in MAT_THERMAL_ISOTROPIC there is always an error. I'll try to turn off these cards and run the calculation. Then I will turn them off sequentially to understand where the error is. Thanks for the advice. I'll write what the result is.

      • javat33489
        Subscriber

        Hello.

        I tried different options but the error still appears.

        I did some tests. I'll tell you more.

        I'm using calculation time 7.5.

        The drill material is plastic kinematic, the material is SPG sand MOHR_COULUMB.

        I wrote above which units I use.

        I manage to make the first entry in d3plot, but at the next step an error occurs.

        I changed the timestep parameters of the temperature solver and the HC and TC parameters in the MAT_THERMAL_ISOTROPIC settings (for drill and sand).

        1. 

        With these settings, the sand temperature is noticeably very high:

         

        2.

        With these settings there are generally negative temperatures

         

        ___

        Where to go next? What to watch or configure? Please tell me?

         

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