Apply a stress on region of a system

Hi ,
System is 2D graphene ribbon both end (red regions) are fixed (no time integration).
Boundaries are P F F
Tensile stresses need to be applied on green regions such that it causes the deformation in y direction of system.
I want to know what are the possible commands(fixes) that can be used to perform the simulation in control manner?

I tried with fix add-force and fix move linear for green regions however it did not work.

If you immobilize the border areas of your sheet, there really is not much of a need for periodic boundary conditions.

The only options that I can think of to apply stress according to your sketch would be fix addforce and fix aveforce. For details, please see their documentation.

“Did not work” is a very unscientific expression and pretty much useless unless you also explain how it did not produce the expected results and what you expected in the first place.

In general, your setup is rather problematic and it is not clear what physically relevant results are even possible with such a complex and unusual setup. What particular property do you want to derive this way, that cannot be obtained with the more conventional approaches. What is the corresponding experiment that you can correlate to. Please keep in mind the length and time scales. For most macroscopic experiments, it is sufficient to determine bulk properties (i.e. with all periodic boundaries).