issues faced in spectrum analysis,sprs on ansys

Hi to all,

 Im a student pursuing my project under GE Healthcare. My problem is basically the analysis of the vibrations on a X-ray tube packaging ( a wooden pallet which is the base) using an electrodynamic shaker. I have tried following Ansys help guide to my fullest extent but still no breakthroughs. Listed below are the issues and doubts im facing:

  1. From what i have understood, we are to input the modes of the modal analysis for the spectrum analysis. But then where are we to input the frequency range of the shaker itself??

 2. I have just theoretically understood that for velocity/acceleration as outputs we are to excite the system at the support and for disp/force excite it away from the support. But how do we implement this practically??

 3. In the sample problem given in Ansys to do with beams, the inputs given in the question has to do with a frequency range and also displacements or the spectral value. How do we determine this displacement or SV?? From what i understood nodal displacements, vel, accelerations are the outputs that we get from spectrum analysis.. ?

4. What is the practical importance of significant threshold??

 I have followed all the steps given in the Ansys helpguide for spectrum analysis and still have not been successfull even after a lot of attempts. So i am assuming it is due to the above problems and am hoping that somebody could help me out with these.

 Thank you !  :)