I guess you should be able to plot the local coordinate system for the interface in ATENA Studio. In the "Labels 'n signals" toolbox, select the option to plot "Element LCSs". Then you should be able to correctly assign the two tangential stresses in the interface to the corresponding directions.

Also, for this purpose, another simple modelling approach would be to use BAR WITH BOND and check the bond stress values.

If I misunderstood something, please let me know. Furthermore, if you need any assistance with the modelling, you can send us your model to our ATENA user's support at cervenka@cervenka.cz

Best regards,
Jiří Rymeš

I made an axisymmetric model including a single circular FRP yarn surrounded by concrete and subjected to tension displacement controlled load. For the first simple try, I considered the material of yarn and concrete as elastic. The interaction between concrete and yarn is modeled by the contact surface (zero thickness surface) with the interface material assigned.

I need to see the bond and slip evolution on the interface. Because the interface has no thickness and the loading somehow that doesn't make the interface open in the normal direction, the interface remains like a line shape. Then when it comes to visualization of interface stress and displacement in the scalar tab of the result module, nothing can be visible on the interface. Indeed I have the legend with values on the up-right side, but I can not recognize the results are related to which location in the interface.

Is there any tips and trick to visualize that?

Best Regards,
Ahmad Delpasand