Organizing sets in 1D Spot connection

Ram Dhiwakar Seetharaman_21015
Ram Dhiwakar Seetharaman_21015 Altair Community Member
edited May 2022 in Community Q&A

I made a 1D spot Rigid connection between two components. I created a set of nodes where the rigids should be created and used to this set as the location to join the two components. The connections were realized but I get a huge number of sets that seem to contain just 1 node. How can I organize all these sets into a single set or how should I make the connection such that I do not get such a high number of sets ?

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Best Answer

  • PaulAltair
    PaulAltair
    Altair Employee
    edited May 2022 Answer ✓

    What you are seeing is expected for the options you have chosen, each Radioss RBODY has its own 'group' (set) of dependent secondary nodes. So you will get a set per connector (you don't want to merge/combine them, that would give you one huge rigid rather than lots of spot connectors, and break all your other spot connectors too) The huge number of sets is unavoidable, you have to have one per RBODY.

    The reason there is just 1 node per set in your case, is that where you create the spot connector realisation type 'rigid' this creates a rigid/RBODY where the independent main node (on your 1st part) is on the RBODY card itself, and the secondary dependent node is in the set you see in the list, while this is ok for some solvers, this is not good practice in Radioss, the Main node (on the RBODY) should be 'free' (i.e. not connected to the structural mesh)

    For Radioss, you should instead use the spot connector realisation type 'rigidlnk(midnode)' this will create a free mid node between your parts (which will be on the RBODY card) and the group (set) will then contain 2 nodes per RBODY (rigid) for the secondaries

    You will still get many sets (now with 2 nodes each), but this is required!

    You should also check after creation, that none of your rigid connections share nodes by using the 1d element dependency check, as this is illegal in Radioss

Answers

  • PaulAltair
    PaulAltair
    Altair Employee
    edited May 2022 Answer ✓

    What you are seeing is expected for the options you have chosen, each Radioss RBODY has its own 'group' (set) of dependent secondary nodes. So you will get a set per connector (you don't want to merge/combine them, that would give you one huge rigid rather than lots of spot connectors, and break all your other spot connectors too) The huge number of sets is unavoidable, you have to have one per RBODY.

    The reason there is just 1 node per set in your case, is that where you create the spot connector realisation type 'rigid' this creates a rigid/RBODY where the independent main node (on your 1st part) is on the RBODY card itself, and the secondary dependent node is in the set you see in the list, while this is ok for some solvers, this is not good practice in Radioss, the Main node (on the RBODY) should be 'free' (i.e. not connected to the structural mesh)

    For Radioss, you should instead use the spot connector realisation type 'rigidlnk(midnode)' this will create a free mid node between your parts (which will be on the RBODY card) and the group (set) will then contain 2 nodes per RBODY (rigid) for the secondaries

    You will still get many sets (now with 2 nodes each), but this is required!

    You should also check after creation, that none of your rigid connections share nodes by using the 1d element dependency check, as this is illegal in Radioss

  • Ram Dhiwakar Seetharaman_21015
    Ram Dhiwakar Seetharaman_21015 Altair Community Member
    edited April 2022

    What you are seeing is expected for the options you have chosen, each Radioss RBODY has its own 'group' (set) of dependent secondary nodes. So you will get a set per connector (you don't want to merge/combine them, that would give you one huge rigid rather than lots of spot connectors, and break all your other spot connectors too) The huge number of sets is unavoidable, you have to have one per RBODY.

    The reason there is just 1 node per set in your case, is that where you create the spot connector realisation type 'rigid' this creates a rigid/RBODY where the independent main node (on your 1st part) is on the RBODY card itself, and the secondary dependent node is in the set you see in the list, while this is ok for some solvers, this is not good practice in Radioss, the Main node (on the RBODY) should be 'free' (i.e. not connected to the structural mesh)

    For Radioss, you should instead use the spot connector realisation type 'rigidlnk(midnode)' this will create a free mid node between your parts (which will be on the RBODY card) and the group (set) will then contain 2 nodes per RBODY (rigid) for the secondaries

    You will still get many sets (now with 2 nodes each), but this is required!

    You should also check after creation, that none of your rigid connections share nodes by using the 1d element dependency check, as this is illegal in Radioss

    Thanks, Paul