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Permanently Modify Input Deck

Permanently Modify Input Deck

Permanently Modify Input Deck

Hi all,

I'm running an analysis with a bunch of linear gap elements and the "Gaps as contact" flag turned on. To make it run correctly to actual convergence, I have been adding a BCTPARM line to control convergence requirements manually by doing the following:

Analysis -> Preview -> Edit Preview (Paste lines from text file I saved with the correct parameters) -> Analyze.

Is there a way to place these lines somewhere where they'll be permanent additions? Adding a contact property does nothing without any actual contact pairs in the model.

I forgot to add them on one of my analysis runs and while I caught it, I could have easily missed it if I hadn't dug into the f06 file to double check. Since it's just a couple of bulk data lines it'd be nice if there was a place to paste them in where they'd get inserted every time the analysis was submitted.


RE: Permanently Modify Input Deck


When you use the Analysis Set Manager and set up the analysis, go to the page "NASTRAN Bulk Data Options". At the bottom right there are two bottons, I suspect that "Start Text" is what you want. Insert the text there in that dialog and it will be written to all your analysis files.

Hope this helps


RE: Permanently Modify Input Deck

since the model ran successfully without this PARAM, were the results any different to the run with the PARAM ?

Possibly that run was just a happy coincidence when the PARAM wasn't active ?

another day in paradise, or is paradise one day closer ?

RE: Permanently Modify Input Deck

Dear EnginerdNate
ThomasH is correct, in this FEMAP tutorial dealing with CGAP elements I show how to enter the number of contact interations for CGAP elements defined directly into the analysis study:

Best regards,

Blas Molero Hidalgo
Ingeniero Industrial

WEB: http://www.iberisa.com
Blog de FEMAP & NX Nastran: http://iberisa.wordpress.com/

RE: Permanently Modify Input Deck

Exactly what I was looking for, thanks to both of you!

rb1957 - What has happens without the param set, is that it runs to 20 outer loops for the contact computation, and then converged or not it just moves on with the analysis with whatever that result is. So in my case, what tipped me off to a convergence problem was that some of my gap elements were showing more deflection than the limit I had specified. When I dug into the f06 file, there was a statement about the iteration limit being hit as opposed to convergence being achieved.

Cheers all!

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