I was trying to model a free-free boundary conditions for a beam which is freely hanged using string on both ends (excuse the drawing):

However, I couldn't find any useful resources on doing so in Abaqus. My questions:

1. If I set the left (vibrator) end as a moving boundary (to simulate the vibrator) and right as simply supported, does the analysis still valid?
2. From this old answer, the author says to "model the geometry symmetric and then fix the symmetry line with boundary condition", what is the boundary condition the author is talking about?
3. If there any other alternative solution to this problem?

Thanks in advance!