Node-Node contact

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  • Last Post 15 January 2019
Amin Al-Fakih posted this 13 January 2019

Dear All,

I am modelling mortarless interlocking masonry prism (3 units height) and I want to define the interface between the brick using CONTA178 and combined with nonlinear spring (COMBIN39). The problem is, the interface between bricks got varies gaps at different locations. Could you please show me how to accomplish this model In ANSYS workbench. 

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peteroznewman posted this 13 January 2019

Dear Amin,

ANSYS members like Sandeep and others are not permitted to download attachments, so I am inserting the images below for their benefit.

In Workbench Mechanical, you can define Frictional Contact by picking one set of faces for the Contact side on one brick, and a second set of faces for the Target side on the other brick.

You could make two sets of contacts, one for the boss and hole interface that might have a large gap, and a second contact for the horizontal faces that are touching.  You might have to manually set the Pinball Radius on the first contact to a large number. This will force the Contact Tool to show that the contact pair with the large gap is Near Open, not Far Open.

Please explain how you want to use the COMBIN39.

Regards,
Peter

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Amin Al-Fakih posted this 14 January 2019

Dear Peter, 

Thank you very much for you response. 

I have done what you have explained which called (surface to surface contact), I got an acceptable results as well. However, I wan t to examine the  dry joint contact behavior where roughness and gaps are consider. I have read a few literature using CONTA52 combined with COMBIN39. They were used nodal degree of freedom coupling technique on nodes 'i' and ' j ' to allow only one directional (longitudinal) displacement of those nodes as shown in the attachment (Picture 1). 

On my case, the horizontal faces contacts are not fully touched. There are gaps of 0.1mm - 0.15mm (as shown in the picture) which I want to use the nonlinear spring (COMBIN39) to connect those nodes and represent the gaps .

Thank you very much

Picture 1Picture 2

peteroznewman posted this 15 January 2019

I understand completely.  I assume you bring this geometry into SpaceClaim. If so, you start a sketch on the plane of contact.

Draw small squares on the face of each block, which will make new faces that you can connect one end of each spring to.

Below I drew squares on the top and bottom rows of points. The benefit of a square is there is a finite area to distribute the force.

If you put all the faces on one block in a Named Selection for the Reference side of the spring, and the matching faces in a Named Selection for the Mobile side of the spring. You can build one spring, then use the Object Generator to automatically make all the other springs. 

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  • Amin Al-Fakih
Amin Al-Fakih posted this 15 January 2019

Thank you very much Mr. Peter. I will try your suggestion and revert to you of the results obtained. 

Many thanks Peter. 

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