Hello, I am afraid there is no direct way to define this using the ATENA GUEs (2D, 3D, GiD).

There is an option of defining a multiplier as a function of distance from cable/bar beginning. All the bond properties are then scaled by this function. To introduce this function, you need to manually modify the ATENA Input File (.inp) before starting the analysis. For details, please see FUNCTION LOCATION in Table 43: &EXTERNAL_CABLE_GEOMETRY_SPEC sub-command parameters in the ATENA Input Manual, and understand the table covers both cables and bars with bond.

If you need help with your model, please it to our general support email along with your ATENA User ID (WR), and some sketches+description of your structure or experiment - we should be able to show you how to edit the .inp file, or, possibly even recommend some other way of modelling, suitable for your needs.