FEMAP contact

[Markeng512]

Hi all,
I run a model in which there is a glue contact. In the f06 I have these warning but I don't now how to interpret them:

*** USER WARNING MESSAGE 4690 (CNTGAPERR)
The gap between glue faces of some elements in gap pair 73 between
regions 3049 and 3063 seems overly large. The largest values are listed
in the table below:

ELEMENT ELEMENT GAP

32100483 31000777 2.50000E+00
32100483 31000868 2.50000E+00
32100485 31001102 2.50000E+00
32100485 31001103 2.50000E+00
32100486 31000777 2.30710E+00
32100498 31001103 2.28164E+00
32100486 31000775 1.13489E+00
32100498 31001104 1.05941E+00
32100487 31000773 5.00000E-01
32100516 31000797 5.00000E-01

Does it mean that the regions are not anymore glued?

 

[Darkmann]

I have used glued contacts successfully for components which actually mate with zero gap, functionally. You do have a gap but it is not clear to me whether or not that is intentional. If functionally you do not need a gap, play with the Glued Contact Property (BGSET) option on the FEMAP Define Connection Property card. There is a Search Distance option you can modify at will.

Here's what's worked for me (I have never posted images on this forum, so I hope this works):

 

[MComposite]

I recommend you to perform modal analysis ( boundary conditions free-free ) and you will see whether the desired components are glued or not. First six modes are rigid body modes with very low frequency. If some contact pair is not good, you will see.

A few days ago, i had the same problem, the same warning message. I was modeling structure which has more than 250 connectors, and i couldn't perform static analysis because Nx Nastran returned me warning message about large gap between some elements of wing skin and ribs. Increasing MAXDi didn't help. I performed modal analysis ( free- free) and there was nothing wrong with the contact pairs and elements from warning message, components were glued. The problem was something else entirely, which has no influence on these elements.

So it doesn't mean that your regions are not connected. Try again, set defaults parameters and increase Max Contact Search Distance. You can use Glued Contact even if there is gap between faces in contact pair, you just need to define adequate search distance.

Best regards