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Nonlinear contact without liftoff

Creator
Creator

Hi,

 

i am working with Siemens NX 11.1 and do my CAE in NX Nastran.

 

As u know there are plenty of options how to deal with penetrations at nonlinear contacts.

But i am searching for an option to surpress the contact to open.

No glueing because both surfaces should still glide on eachother with no friction.

 

I tried the option "tied" at options for constrained contact (SOL 601) , but it was the same as if i glued both surfaces.

 

So force that usually would lift off the surface or parts from the surface from eachother, should be transfered by the contact.

In Ansys there is an option called "bonded" i think, that prevents nonlinear contacts from lifting off and its still able to slide.

 

Is there an option to get such a non-lifting nonlinear contact in NX Nastran?

 

 

 

Greetings

 

David

 

3 REPLIES

Re: Nonlinear contact without liftoff

Solution Partner Pioneer Solution Partner Pioneer
Solution Partner Pioneer
David, it is not a GLUE, it is not a CONTACT, it is not a SLIDING CONSTRAINT because you do not move on GROUND but BOTH of your surfaces must be free to move in space. So it is an EQUATION that must tell to NX the displacements of the 2 surfaces along ONLY the normal direction of the 2 surfaces are linked and must be the same in both directions. If so in linear solutions the NASTRAN card to define EQUATION is called MPC (multipoint constraint) and must be defined between 2 facing grids (so same grids position on both surfaces). I think you can use it in non linear solutions too but the connected grids remain always the same. Franco

Re: Nonlinear contact without liftoff

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Dear David,

The new nonlinear MultiStep module of NX NASTRAN (SOL401) available in future FEMAP V12 will support the option to glue elements together using SLIDING GLUE

By default, the glue formulation in SOL 401 creates a connection which prevents relative motion in all directions. But you can also optionally turn on the sliding glue formulation for both the surface-to-surface and the edge-to-edge glue conditions. Sliding glue includes a normal stiffness but no tangential stiffness, and is requested by defining the parameter setting SLIDE=1 on the BGPARM entry.

Best regards,
Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: Nonlinear contact without liftoff

Creator
Creator

Okay, thanks for your replies!