How to rupture 3D elements in Radioss?

Anuj Nandal_22610
Anuj Nandal_22610 New Altair Community Member
edited April 2023 in Community Q&A

I am trying to drop a ball on to a plate. The ball has imposed Velocity. All elements are of 3D type. In material (LAW2) I have given a failure criteria (epsp max), the elements don't rupture. Even after crossing the limit. Am I missing something? Also How do we check Von Mises strain in the component. We have option to browse plastic strain but not any other types. I am attaching the starter and engine file for reference. Can someone help here please?

Best Answer

  • PaulAltair
    PaulAltair
    Altair Employee
    edited April 2023 Answer ✓

    Hi Tayfun, thanks for the quick reply. Generally we get only tensile test data. In that case it becomes difficult to use failure model. Do we have a way where I could rupture the element automatically when maximum strain is reached? I tried with epsp max in the material, It is in the file that I had shared but looks like its not working. 

    the epsp max in material will not rupture solid elements, this is the expected behaviour, you may use a /FAIL model to rupture them instead, It is not complex to use the /FAIL models, if you only have tensile data, then you may choose to use that value only for all directions (set only D1 in /FAIL/JOHNSON for example) or you can use /FAIL/BIQUAD with some material defaults (Mflag) to use the tensile failure strain to set relative values in other modes

Answers

  • TayfunBaskara
    TayfunBaskara Altair Community Member
    edited April 2023

    Hello Anuj,

    If you define additional failure model depending on the material you can see ruptured elements as in the picture below. I defined a Johnson failure model with dummy parameters to see ruptured elements in the picture. You can also examine Failure Models for Ductile Materials using links below.

    https://2022.help.altair.com/2022.3/hwsolvers/rad/topics/solvers/rad/failure_materials_explicit_fea_r.htm

    image

    For your second question, you can already see vonMises Strain in HyperView.

    image

    Best Regards

    Tayfun

  • Anuj Nandal_22610
    Anuj Nandal_22610 New Altair Community Member
    edited April 2023

    Hello Anuj,

    If you define additional failure model depending on the material you can see ruptured elements as in the picture below. I defined a Johnson failure model with dummy parameters to see ruptured elements in the picture. You can also examine Failure Models for Ductile Materials using links below.

    https://2022.help.altair.com/2022.3/hwsolvers/rad/topics/solvers/rad/failure_materials_explicit_fea_r.htm

    image

    For your second question, you can already see vonMises Strain in HyperView.

    image

    Best Regards

    Tayfun

    Hi Tayfun, thanks for the quick reply. Generally we get only tensile test data. In that case it becomes difficult to use failure model. Do we have a way where I could rupture the element automatically when maximum strain is reached? I tried with epsp max in the material, It is in the file that I had shared but looks like its not working. 

  • Anuj Nandal_22610
    Anuj Nandal_22610 New Altair Community Member
    edited April 2023

    Hi Tayfun, thanks for the quick reply. Generally we get only tensile test data. In that case it becomes difficult to use failure model. Do we have a way where I could rupture the element automatically when maximum strain is reached? I tried with epsp max in the material, It is in the file that I had shared but looks like its not working. 

    Also could you please share your file for reference

  • PaulAltair
    PaulAltair
    Altair Employee
    edited April 2023 Answer ✓

    Hi Tayfun, thanks for the quick reply. Generally we get only tensile test data. In that case it becomes difficult to use failure model. Do we have a way where I could rupture the element automatically when maximum strain is reached? I tried with epsp max in the material, It is in the file that I had shared but looks like its not working. 

    the epsp max in material will not rupture solid elements, this is the expected behaviour, you may use a /FAIL model to rupture them instead, It is not complex to use the /FAIL models, if you only have tensile data, then you may choose to use that value only for all directions (set only D1 in /FAIL/JOHNSON for example) or you can use /FAIL/BIQUAD with some material defaults (Mflag) to use the tensile failure strain to set relative values in other modes