contact opening

[Zigmhount]

Hi all,

I have a model with a pre-stressed bolt and a contact connection between two solids. In addition there is a traction force on one solid.
I'd like to watch the contact status (if there is contact or not) and possibly the gap between the surfaces when there isn't any contact (similarly to COPEN variable in Abaqus maybe)...

I'm thinking of output processing: Substraction between the translation components of the nodes on one surface and those of the nodes on the other surface.
But there is a problem if both surface have different mesh sizes...

Does someone have an (great) idea?

Thanks
Simon

 

[BlasMolero]

Dear Simon,
When you solve a surface-to-surface contact problem between the results you can plot the contact pressure, then you can see the extension of closed surface-to-surface compression contact elements.

Of course, when dealing with surface-to-surface contact problems is very important to select correctly the TARGET (or MASTER) & SOURCE (or SLAVE) regions, remember the SOURCE region should be the one with the most refined mesh. My recomendation is always to use the same mesh density in both contact regions, this is the best setup.

Best regards,
Blas.

 

[BlasMolero]

Dear Simon,
In addition please note that under nastran case control you have to set BCRESULTS parameters in order to:
• Specifies whether to output contact results for contact nodes
• If requested, contact force results are output at all nodes on both contactor and target contact regions
• If requested, contact traction results are output at all nodes on contactor regions only

Example:
BCRESULTS(TRACTION,PLOT)=ALL
• Request contact tractions, contact force or both
• Traction results are contact pressure (scalar) and in-plane contact tractions (vector in basic coordinate system). In-plane contact tractions gives the traction force due to frictional contact. Traction results are output for all contact nodes on the contactor regions only.
• Contact force is a vector result in the basic coordinate system. Force results are output for all contact nodes on both the contactor and target regions.

Best regards,
Blas.