According the basic theory of forced vibration[1], before entering the steady-state response, there is a short duration for so-called "transient" state vibration. I'm wondering how long is this "transient" state? How can I compute its duration?
[1]Introduction to Dynamics and Vibrations http://www.brown.edu/Departments/Engineering/Courses/En4/Notes/vibrations_forced/vibrations_forced.htm