Spring Element in Pre-stressing of Cables in Concrete

[Zain_117]

Hello,
I am trying to model prestressing in cables (strands) in concrete. I am trying to replicate the model as in the paper attached. In the paper, the author mentioned the spring elements between concrete and strands interface. Can anyone help me how to introduce the spring element for interface modeling?
FYI: I have done all the required processes like surf-surf interaction.

 

[Zain_117]

The screenshot related to the spring element assignment is given as an attachment (Page 6/16).

"In this study, the steel used was not ribbed and the consideration of interfacial behavior is limited to bond-slip behavior idealized by using interfacial distributed spring elements of zero dimensions to transfer normal and tangential forces at the interface"

Can anyone help me to model the spring element?