Contact without Penetration


Dear All


I am a FEMAP beginner user.

Kindly please help me to find a solution of the issue I had face.

I want to anaylise the equipment shown below

Swevelling Padeye.JPG


The model consist 3 part

1. The inner pipe

2. Connector part (blue color)

3. Padeye (white color)


The boundary condition is fixed in the both edge of the inner pipe. And the load are applied trough the ridgd link (RB2) in the padeye hole (red color).

I also have apply the connector contact region between all of the part.

But, after I run the model, the connector part is penetrate the inner pipe part, as shown below.

Swevelling Padeye 2.JPG


I guess this result is wrong. There is should beno peteration between the parts if I have modelled the conector in right way.

Here I attche my model.


Please if anybody could help me.



Re: Contact without Penetration

Siemens Phenom Siemens Phenom
Siemens Phenom

The issue with your model is your Connection Property.  If you have touching regions, you should set the Initial Penetration Setting to 3..Zero Gap/Penetration.  With this setting NX Nastran, NX Nastran sets areas where intial penetration exists to zero.  Normally, this occurs when the mesh does not match on adjactent surfaces as shown below from your model.



In addition, you should reduce the value of the Max Contact Search Distance to a value larger than the maxium inital seperation distance.  This will help speed up the NX Nastran solution.


In you case, I set the Initial Penetration Setting to 3. and the Max Contact Search Distance to 10.  With these settings, I get the following results.  Note the Maximum Von Mises Stress is considerably less than the default settings as shown below.


I also recommend that when displaying deformed results on an assembly, you set the Scale type to Actual Deformations, then set a scale value for that.




Best Regards,
Chip Fricke
Principal Applications Engineer - Femap Product Development

Re: Contact without Penetration

Hi Chip Fricke.

Thank you very much for your answer.

Really appreciated!