Thanks for your response and your sharing. I already saw this course and, as i'm calculating displacement by hand (in matlab), this course doesn't correspond to what i'm looking for. Indeed, i want to know what follow:

I know that the residual vector option lets ansys write a last column in the mcf file which correspond to a pseudo-mode (the 11th in my original message). I also know that I have to add it to the displacement calculated by the mode superposition method :

So the result with residual vector gives me something like this:

Where {u_res} is the residual vector calculated by ansys in the mcf file (the last column).

And lambda is the corresponding coordinate (that's something i've found after writting this post). For exemple, in my example, i found empirically that lambda = -0.135 gives me the exact graph i want (the same as ansys), but i don't know how to find that coordinate (somewhere in the rst file ?). If you have any idea, let me know