Constraint Compiling in HM8.0

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hello

I'm fairly new to hypermesh. I'm using version 8.0 with LS-Dyna as a solver. I have a series of simulations which need remeshing inbetween them. To do this I've imported the LS-Dyna output file into hm (after the first simulation), did my changes (trimming some of the original mesh, creating a null mesh, and relocating one mesh relative to the global coordinates). My problem comes into play when I try to export the data back to a LS-Dyna file. Since symmetry allows me to simulate half of the real life structure, constraints are applied to the axis of symmetry along with position constraints of the device itself. These constraints are listed under the *BOUNDARY_SPC_NODE card but nodes are double listed with different constraints causing errors in LS-Dyna. For example :

*BOUNDARY_SPC_NODE

308579 0 1 1 1

308579 0 1 1 1

How can I compile all the data into a single listing for each node? for example

*BOUNDARY_SPC_NODE

308579 0 1 1 1 1

Thanks in advance for any help.

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Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2008

    Run 'Error Check' found in the 'DYNA Tools' of 'Utility browser' (From pull down menu, View --> Utility Menu). Be aware that you have to be in the LsDyna user profile.

    Check the 'BCS' option found in 'LsDyna Error Check' window.

    If there are duplicate loads (*BOUNDARY_SPC_NODE) in the model, error check utility will identify the node numbers which have duplicate loads and also gives you an option to merge them.

    An example of the sample message is given below.

    Boundary_spc on node 121 was found to have multiple *boundary_SPC defined through loads (ids : 6 5 4 ) - Click here to merge all the SPC's for this node

    Clicking the merge option will resolve your issue.

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