Assistance Needed for Converting a LS-DYNA Barrier Model to Radioss

Khazri Jaber
Khazri Jaber Altair Community Member
in Community Q&A

Hello everyone,

I am currently working on a project to model and simulate the impact of a motorcyclist against a road barrier to assess injuries, both with and without the use of an airbag.

  • Project Context:
    • The airbag and motorcyclist models have been fully developed and are functioning correctly in Radioss.
    • The barrier model, however, was retrieved from previous work and was initially developed in LS-DYNA. I am now in the process of converting this model to integrate it into Radioss.
  • Issue Encountered:
    • I used Altair's Convert tool for the conversion. Unfortunately, I noticed that some data, such as the details for bolts, seem to have been lost or misinterpreted during the process.
    • My objectives are as follows:
      1. To determine if there is a method or process that allows the conversion of an LS-DYNA model to Radioss while retaining all information (materials, properties, contacts, etc.).
      2. To verify that the converted Radioss model is identical to the original LS-DYNA model.
  • Specific Cards Requiring Conversion:
    • The *MAT_SPOTWELD_TITLE card used for welds.
    • The *INITIAL_AXIAL_FORCE_BEAM card used to initialize axial forces in beams.

I am attaching both versions of the model (LS-DYNA and Radioss) to this message for reference. If anyone has suggestions or experience with this type of conversion, I would greatly appreciate your guidance:

  • Is there a way to ensure all data is preserved during the conversion?
  • How can I verify that the Radioss model accurately replicates the original LS-DYNA model?
  • If necessary, how can I manually recreate or adapt specific cards, such as those mentioned above, in Radioss?

Thank you in advance for your help!

Best regards,

SPM.k
SPM_0000.rad
SPM_0001.rad

Tagged:

Answers

  • Guilherme_Brandao
    Guilherme_Brandao
    Altair Employee

    Hello @Khazri Jaber

    The best way to convert a Dyna model to Radioss is by using the Altair D2RAD converter, which is inside Altair Compute Console → Apps → Altair Radioss Converter:

    image.png

    The keywords you mentioned (*MAT_SPOWELD and *INITIAL_AXIAL_FORCE_BEAM) are supported by the 2024.1 converter. You can find the complete list of the supported keywords here: LS-Dyna Input

    At the end of the conversion, a log file will be created showing how each keyword was mapped and listing any keywords that couldn't be mapped, if any.

  • Khazri Jaber
    Khazri Jaber Altair Community Member

    Bonjour @Guilherme_Brandao

    Thank you for your response and the information regarding the use of the Altair D2RAD converter in version 2024.1. However, I am currently working with version Compute Console 2022.2, which does not have the latest improvements to the converter.

    I would like to know if the converter available in this version (2022.2) can also handle keywords like *MAT_SPOTWELD and *INITIAL_AXIAL_FORCE_BEAM when converting a model from LS-DYNA to Radioss. If not, could you guide me on how to proceed manually or with additional tools to effectively convert the models?

    Additionally, I would appreciate any further information or resources to successfully perform the conversion using my current version.

    Thank you in advance for your help!

  • Guilherme_Brandao
    Guilherme_Brandao
    Altair Employee

    Hi, you can find the keyword mapping in the Radioss Reference Guide:

    MAT_SPOTWELD mapping: https://help.altair.com/hwsolvers/rad/topics/solvers/rad/mat_100_spotweld_lsdyna_r.htm

    INITIAL_AXIAL_FORCE_BEAM mapping: https://help.altair.com/hwsolvers/rad/topics/solvers/rad/initial_axial_force_beam_lsdyna_r.htm

    At the end of each section, you'll find comments indicating the corresponding Radioss entities. These references will guide you to each Radioss keyword page and give a detailed setup description.

Categories