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Contact Analysis - SOl101

Hi,

 

I'm having difficulty getting a contact to work. The initial gap between the 2 contact surfaces is 0.2". Using Sol101. The picture attached shows a bar attached to a dummy shell thru RBE2. The picture shows only 1% pin contact.jpg

of the whole model. The idea behind this model is let the pin move 0.2" before it starts reacting any load. The checked the normals, surfaces, max search dir, switched master/slave etc, but nothing worked. Hpin contact1.jpg

3 REPLIES

Re: Contact Analysis - SOl101

May be the huge pictures chopped the message. The 2nd picture shows the final deformation. I appreciate any help/Ideas.

 

Thank you.

KR

Re: Contact Analysis - SOl101

Hello!,

Plot element normals, to develop contact the region´s element normals should point one againts the other, this is a common error. NX NASTRAN creates a contact element if any of the source element normals intersect with an element in the target region.

  • Make sure the source region is the cylinder and the target region is the more stiffer, ie, the dummy shell.
  • I would split the cylinder surfaces in 4 parts, making 4 contact connector pairs instead only one for 360º, this increase the contact accuracy.
  • Also plot deformed shape at scale 1:1, this is linear contact and depending of displacements the scale of results could be exagerated.

SHOW-NORMALS.png

If not arrived to a valid solution, post your FEMAP model here and we can take a look to it, OK?.

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: Contact Analysis - SOl101

Assuming your displacement plot is 1:1 scale instead of % of model scale, then you may have a problem that every contact node is a dependent / constrained DoF. You may need to use beams instead of RBE (eg. convert via Custom Tools -> Element Update -> Convert RBE to Active Beam) and perhaps Reverse the connector as well if necessary as it may make a difference whether the Target or Source is the fully constrained region. Check the .f06 text for warnings.