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Solid body penetration with surface-to-surface contacts

Hi,

 

I am modelling a tunnel structure in Siemens NX 11. Separate tunnel segments are loaded and between the segments, a surface-to-surface contact is modelled. Due to the compressive loads, the tunnel segments are pushed against each other. Initial penetrations were set to 0 and small displacements-method is assumed.

 

When I run this model (using a SOL601), results show that the tunnel segments are penetrating into each other, which is off course not desired. Consequently, displacements are way more than allowable...

 

Can anyone help me to encounter this problem?

 

In attachment, I zipped the model files.

 

Thank you!

4 REPLIES

Betreff: Solid body penetration with surface-to-surface contacts

SanderK,

 

as I do not use NX11, can you post some pictures of the model and the results of penetration? - May be there is somebody who can give you further advices.

 

Thank you and best wishes, Michael.

Betreff: Solid body penetration with surface-to-surface contacts

I solved the model a couple times with slight changes. I can't figure out why the contact is showing interferences, but it definitely is, and it definitely makes no sense to me. This may be worth sending to GTAC for assistance.

 

Regards,

Mark

Solution
Solution
Accepted by topic author sanderk
‎04-24-2017 06:39 PM

Re: Solid body penetration with surface-to-surface contacts

The contact penetrations are due to the large compliance factor that you are using. The provided deck has CFACTOR1 set to 0.01.

 

The typical range of values used for CFACTOR1 are 1e-8 to 1e-5. A value of 0.01 results in very soft contact with excessive penetrations.

 

See the section "Contact surface compliance" in section 4.4 of the Advanced Nonlinear Theory and Modeling Guide

 

Re: Solid body penetration with surface-to-surface contacts

Thank you for the replies.

Indeed, the compliance factor was way too large. I set CFACTOR1 equal to 1e-05 and the corresponding EPSN-value at 1e-12. Now I'm obtaining more realistic results.

Thanks a lot!