Unable to create bonds between irregular particles and spherical particles

Chao
Chao Altair Community Member
edited March 2023 in Community Q&A

Hi,

I create some irregular shape particles as aggregate and set the contact radius (in Fig.1).

Then, I filled a specimens with these irregular particles and spherical particles and compacted these aggregates as a cylindrical specimen (in Fig.2).

After I got this cylindrical specimen, I used the bonding model (in Fig.3) to create bonds between particles and then want to do the simulation of the uniaxial compression test.

However, there were no bonds created (in Fig.4) between particles and the particles in this cylindrical specimen failed at the beginning of the uniaxial compression simulation.

Therefore, I would like to know how to create bonds between these clump of irregular particles and spherical particles.

Kind regards,

Chao

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Best Answer

  • Stephen Cole
    Stephen Cole
    Altair Employee
    edited November 2022 Answer ✓

    Hi CHao,

     

    The bond time is set to 2 s, has the simulation passed this time point?  It should only create bonds between the specified particle types if they are in contact at that point in time.

     

    I see you are using the original 'bonding' model.  I'd recommend using Bonding V2 as you can run this on the GPU.  Bonding V2 uses 'contacts' rather than 'bonds' to calculate the bond forces.  The two models have similar input only that the V2 allows the addition of a range of bond stiffness values (set range to 0 to be same as v1) and also V2 sets the 'bond disk scale' not 'bond disk radius'.  The bond disk radius = bond disk scale * smallest radius in a contact pair.


    Regards

    Stephen

Answers

  • Stephen Cole
    Stephen Cole
    Altair Employee
    edited November 2022 Answer ✓

    Hi CHao,

     

    The bond time is set to 2 s, has the simulation passed this time point?  It should only create bonds between the specified particle types if they are in contact at that point in time.

     

    I see you are using the original 'bonding' model.  I'd recommend using Bonding V2 as you can run this on the GPU.  Bonding V2 uses 'contacts' rather than 'bonds' to calculate the bond forces.  The two models have similar input only that the V2 allows the addition of a range of bond stiffness values (set range to 0 to be same as v1) and also V2 sets the 'bond disk scale' not 'bond disk radius'.  The bond disk radius = bond disk scale * smallest radius in a contact pair.


    Regards

    Stephen

  • Trung Dinh Hoang
    Trung Dinh Hoang New Altair Community Member
    edited March 2023

    Hi Chao 

    I am wondering wether you have found out the solution or not. If you have any information, could you please give me some hints?

    Thank you very much. 

    Regards

    Hoang Dinh Trung 

  • Stephen Cole
    Stephen Cole
    Altair Employee
    edited March 2023
    Trung Dinh Hoang said:

    Hi Chao 

    I am wondering wether you have found out the solution or not. If you have any information, could you please give me some hints?

    Thank you very much. 

    Regards

    Hoang Dinh Trung 

    Hi Hoang, there is a tutorial on the bonded model if this helps:

    https://community.altair.com/community?id=kb_article_view&sysparm_article=KB0037188

    Summary of all the tutorial materials:

    https://support.altair.com/community?id=community_blog&sys_id=5e7dc459979de950e3b0361e6253afae

     

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