Hello,
 

In the steady-state direct step, I wanted to set up loads that vary in phase and magnitude over the frequency, but found that the tabular amplitude only allows 2 entries, not one for each frequency. Also, I can unfortunately not use user subroutines like UAMP  as they are not included in the teaching license for students. How can I run an FEA in the frequency domain (=harmonic) with loads that change over the frequency? 

This is the problem I am trying to solve: 

I have a floating steel shell-element body subject to harmonic loads. The loads were obtained from a linear hydrodynamic model that computes steady state forces and rigid body motions frequency by frequency for steady sinusoidal waves. At every frequency (about ~50 frequencies, far below eigenfrequencies), the loads have different phases and magnitudes. My goal is to compute stress and strain fields for every frequency and later calculate fatigue. I do not need to account for any nonlinearities. The steady-state direct method therefore seemed the most suitable step but with the limitations described above and can currently just use it for a single frequency, not the whole set.

 

Any help is very much appreciated.