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Is there any fast tip to transform APEX glued connection to sliding contact?

if I export a *.bdf file is there any quick script change to perform a Nastran analysis simply editing contact on a txt editor.Grinning
 
Thank you all
  • Change the IGLUE parameter on the BCONPRG entry to 0. this is for touching contact instead of glue. I also suggest removing or resetting the ERROR parameter as the tolerance specified by apex for glue is likely not appropriate for touching contact.
     
    this is a great application for a script. apex can automatically execute a script after bdf export. the script could read the bdf and make the changes automatically.
  • It's not so easy to switch from permanent glued contact to touching contact. You have to add at least friction and a friction coefficent in the BCPARA or BCONPRP card. If all your parts are touching contact bodies you can think about automatic contact in Nastran 2018 using BCONTACT=AUTO,Touch.
  • Good morning.
    Thank you for your suggestions. I've tried the setup of an analysis with the change in the BCONPRG parameter and it is working.
    If in Apex you just rename the glue contact and then you look for the specific card BCONPRG it is possible to set the IGLUE coefficient to 0.
     
     
    --------------------------------------------------------------------
    $ Permanent Glue Interaction: PatchCARRELLO
    BCONECT 21     21             5      8
    BCONPRG 21                     COPTS  10     COPTM  10     ERROR  +
    +      .5     IGLUE  0
    --------------------------------------------------------------------
     
    ... it seems to work and looks like the equivalent of a patran setup.. so lets hope for the best and for a good convergence.
     
     
  • Hello everyone!
    How do you increase the speed of a model created changing the IGLUE coefficient to 0?
    When the model is small there is no need of further adjustment, but when the number of DOF grows it looks like the analysis is always very expensive considering time.
     
    Any smart suggestion to avoid Patran?
    How do I introduce friction in a mixed situation with "glued" and "touch" contact at the same time?