Damping required to give as input to the FEA simulation.

In that paper, the measured damping ratio varied from 0.14 to 0.55% for different beams at the three resonant frequencies when tested at 0.2g.

1) How to measure damping for the main beam and branched beam separately?

2) How to apply impulse excitation to the beam to measure damping for the main and branched beam?